C — https://home.cern | BeaverCheck Audit

Site Health

Score: 73 / 100

Based on 8 categories, 0 sections

Decent speed, but optimizing further could improve engagement.

Several missing protections leave your users and data exposed.

Several issues make your site difficult for assistive technology users.

Well-optimized for search — your content is discoverable.

Solid infrastructure — fast server responses across the board.

Mostly compliant — a few items need attention.

Missing metadata means poor previews on social media and search.

Heavier than average — reducing page weight saves energy and bandwidth.

How is this calculated?

The overall score is a weighted average of individual category scores. Categories with more impact on user experience and security carry more weight.

Performance 25%Security 25%Accessibility 15%SEO 10%Infrastructure 10%Compliance 8%Content 5%Sustainability 2%

Weights reflect general web best practices. Individual needs may differ.

How the composite score is calculated

How you compare

Drupal · 358 peers

You 73

Avg 73

At average

0 50 100

Better than 36% of Drupal sites See full Drupal benchmark →

Bootstrap · 807 peers

You 73

Avg 73

At average

0 50 100

Better than 42% of Bootstrap sites See full Bootstrap benchmark →

Top Priorities (5)

Content-Security-Policy header is missing

Security gaps expose your site and users to attacks, eroding trust.

Security › Security Headers

HSTS header is missing

Security gaps expose your site and users to attacks, eroding trust.

Security › Security Headers

No Content-Security-Policy header found

Security gaps expose your site and users to attacks, eroding trust.

Security › Content Security Policy

Page weighs 17.6 MB (16.5 MB transferred)

Performance issues directly impact user engagement and conversion rates.

Performance › Page Weight Budget

38 link(s) with no accessible text

Accessibility issues exclude users with disabilities — up to 15% of your potential audience.

Accessibility › Link & Button Quality

View fix priority matrix

Fix Priority Matrix

5 findings

Impact

Quick Wins

High impact, low effort — start here.

Strategic

High impact, requires investment.

Easy Improvements

Small gains, minimal effort.

Nothing in this quadrant — good news.

Deprioritize

Low impact, high effort — do last.

Nothing in this quadrant — good news.

← Low effort High effort →

Embed this badge

Markdown

[![BeaverCheck](https://beavercheck.com/badge?url=https%3A%2F%2Fhome.cern)](https://beavercheck.com/results/477ced17-db0a-4129-b87b-073465c02955)

HTML

<a href="https://beavercheck.com/results/477ced17-db0a-4129-b87b-073465c02955"><img src="https://beavercheck.com/badge?url=https%3A%2F%2Fhome.cern" alt="BeaverCheck Score"></a>

Image URL

https://beavercheck.com/badge?url=https%3A%2F%2Fhome.cern

This badge auto-updates with your latest scan result.

What fixing these means

Your site performs reasonably well, but a few targeted fixes could meaningfully improve results. Your LCP of 85.0s exceeds Google's 2.5s 'Good' threshold and the 1 performance issue below directly contributes to it. Accessibility issues exclude users who rely on assistive technology — an estimated 15% of your potential audience. Addressing the critical issues below would have the most immediate impact on your user trust.

3 security gaps detected — browsers may warn visitors about your site.

Your LCP is 85.0s — fixing the 1 performance critical could bring it under Google's 2.5s 'Good' threshold.

1 accessibility issue excludes users who rely on assistive technology.

Conversion Barriers

2 critical 6 warning

8 barrier(s) likely increasing bounce by ~29%.

Speed (2)

Page takes 85.0s to load

+12% bounce

Users abandon at ~3s — you're 82.5s over the 2.5s threshold

Fix: Optimize render-blocking resources, preload the hero image, and compress images

High main-thread blocking time

+2% bounce

Page is non-interactive for 400ms after first paint

Fix: Defer third-party scripts and split large bundles

Trust (2)

No HSTS header

+1% bounce

Returning visitors are briefly exposed to downgrade attacks on first request

Fix: Set Strict-Transport-Security: max-age=31536000; includeSubDomains

No Content-Security-Policy header

+1% bounce

Higher XSS blast radius — one compromised script can exfiltrate the checkout form

Fix: Ship a reporting-only CSP first, then enforce once violations are clean

Content (2)

No Open Graph tags

+2% bounce

Links shared on LinkedIn / Slack / Facebook show bare URLs — referral clicks drop

Fix: Add og:title, og:description, og:image, og:url to the page head

No structured data

+2% bounce

No rich-result eligibility in Google — lower SERP CTR vs competitors with stars and prices

Fix: Add JSON-LD for your page type (Product, Article, FAQPage, LocalBusiness, …)

Navigation (2)

38 link(s) with generic text ("click here", "read more")

+1% bounce

Screen-reader users navigating by link list see no context — and search engines can't infer relevance

Fix: Rewrite with descriptive phrases that identify the destination

53 broken link(s) on the page

+5% bounce

Clicks land on 404s — trust drops and the session often ends

Fix: Fix or remove the broken destinations surfaced on the Content tab

Preliminary CRO audit — each barrier links to the tab with detailed analysis.

Return on Investment

CHF 650 investment → CHF 3.67/month returns + CHF 250,000 risk avoided

Payback period: > 2 years First-year ROI: -93%

Investment

CHF 650

5h · 5 findings

Monthly returns

CHF 3.67 /mo

~CHF 44 / year

Bandwidth savings CHF 3.67

Regulatory risk avoided

CHF 250,000

if kept compliant

nDSG/FADP CHF 250,000

CHF 195 — in quick wins — start here for the fastest payback

Figures combine localized regulatory fine ceilings, search/conversion value priced against local CPC, and bandwidth waste estimates. Results depend on implementation quality and audience composition. Not legal or financial advice.

Full methodology & sources

Estimated Remediation Cost

CHF650

5.0 developer hours at CHF130/hr

Based on Switzerland rates (CHF130/hr)

Quick wins

CHF195 3 fixes in ~90 minutes

Start here for the best return on investment

Cost by category

Cost by effort level

Adjust assumptions

Custom rate

CHF /hr

Rates reflect fully-loaded developer cost including overhead

How developer rates are sourced

What Inaction Is Costing You

CHF 20,837 / month at risk

~CHF 250,044 / year if left unfixed

Compliance Risk

CHF 250,000

nDSG/FADP

No privacy policy link detected
nDSG/FADP: CHF 1,000 – CHF 250,000
Trackers detected but no cookie policy found
nDSG/FADP: CHF 1,000 – CHF 250,000
Trackers detected but no privacy policy found
nDSG/FADP: CHF 1,000 – CHF 250,000

Bandwidth Waste

CHF 3.67 /mo

51801.9 MB/mo × 0.071 CHF/GB

Optimize transfer: save ~5.2 MB per page load
Saves CHF 3.67/mo

Compliance figures represent the statutory maximum fine for the most severe triggered category, capped per regulation — not the sum of per-finding penalties. Based on published regulatory fine ranges. This is not legal advice.

Compliance methodology · SEO assumptions · Bandwidth model

Your performance is already good — improvements may show diminishing returns

Monthly visitors

Unique monthly visitors from your analytics

Conversion rate (%)

Purchases, signups, or key actions

Avg. order value

Optional — for revenue estimation

additional conversions/month

more engaged visitors from reduced bounce

potential monthly revenue

Current bounce (est.)

After fixes (est.)

Estimated bounce reduction

Fix 5 critical issues to capture this value

How this is calculated

Based on Google/Deloitte research ("Milliseconds Make Millions") showing a ~7% bounce rate increase per additional second of LCP above the 2.5s "Good" threshold.

Your site's LCP: → estimated after fixes.

These are estimates based on industry research — actual results vary

Bounce-rate model & assumptions

Your data stays in your browser — nothing is sent to our servers

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Lighthouse Scores

Industry-standard audits powered by Google Lighthouse.

Performance

Accessibility

Best Practices

100

SEO

Core Web Vitals

Key metrics that affect user experience.

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

3.92 s

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

84.96 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

400 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.013

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

5.93 s

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

85.84 s

Detailed Report

Audit breakdown by category with detailed findings.

Performance

Insights

Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling

Why this matters

Shipping ES5 transpiled code to modern browsers wastes bytes — every user with an evergreen browser pays for compatibility you don't need.

Learn more ▾

Most users today run browsers that natively support ES6+, async/await, optional chaining, and the rest of modern JavaScript. Transpiling to ES5 'just in case' adds 20-40% to your bundle for no benefit. Configure your build to target a modern browserslist, or ship a differential bundle pair (modern + legacy) with the module/nomodule pattern.

Source: Google web.dev / Lighthouse

3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.

Why this matters

Performance issues directly impact user engagement and conversion rates.

A long cache lifetime can speed up repeat visits to your page. Learn more about caching.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Request	Cache TTL	Transfer Size
/sites/default/files/styles/large/public/2026-04/Kart-144...	0.0 ms	237.7 KiB
/sites/default/files/styles/large/public/2026-04/ATLAS-Ev...	0.0 ms	101.1 KiB
/sites/default/files/styles/large/public/2026-04/ATLAS_co...	0.0 ms	100.3 KiB
/sites/default/files/styles/large/public/2026-03/Toponium...	0.0 ms	91.9 KiB
/sites/default/files/styles/large/public/2026-04/collisio...	0.0 ms	62.8 KiB
/sites/default/files/styles/large/public/2026-03/Mosaic_s...	0.0 ms	32.3 KiB
/sites/default/files/styles/large/public/2026-04/IMG_7455...	0.0 ms	30.5 KiB
/sites/default/files/styles/large/public/2026-03/Image_Ch...	0.0 ms	16.7 KiB

Consider setting font-display to swap or optional to ensure text is consistently visible. swap can be further optimized to mitigate layout shifts with font metric overrides.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Est Savings
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/bold.woff2	65 ms
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/regular.woff2	60 ms
framework.web.cern.ch/framework/3.0/fonts/open-sans/bold.woff2	60 ms
framework.web.cern.ch/framework/3.0/fonts/cern/cern.woff2	60 ms
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/semibold.woff2	60 ms
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/light.woff2	60 ms

A forced reflow occurs when JavaScript queries geometric properties (such as offsetWidth) after styles have been invalidated by a change to the DOM state. This can result in poor performance. Learn more about forced reflows and possible mitigations.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:source label:Source valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]

items: [map[reflowTime:35.723 source:map[column:14526 line:2 type:source-location url:https://framework.web.cern.ch/framework/3.0/js/scroll-magic/ScrollMagic.min.js urlProvider:network]]]

Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL	Resource Size	Est Savings
div.owl-stage > div.owl-item > div.header-block > div.background-component `div.owl-stage > div.owl-item > div.header-block > div.background-component`	home.cern/sites/default/files/2026-04/Antimatter-3.png	5.0 MiB	4.0 MiB
div.owl-stage > div.owl-item > div.header-block > div.background-component `div.owl-stage > div.owl-item > div.header-block > div.background-component`	home.cern/sites/default/files/2026-04/g2-experiment_1.png	4.7 MiB	3.7 MiB
Plan your CERN visit `div.component-row__row > div.component-row__column > div.box-effects-wrapper > div#preview-card--8`	home.cern/sites/default/files/2025-12/202310-230_50_2_1.jpg	1.1 MiB	868.3 KiB
div.owl-stage > div.owl-item > div.header-block > div.background-component `div.owl-stage > div.owl-item > div.header-block > div.background-component`	home.cern/sites/default/files/2026-04/Toponium.png	1.3 MiB	275.0 KiB
W and Z bosons `div.component-row__row > div.component-row__column > div.box-effects-wrapper > div#preview-card--23`	home.cern/sites/default/files/2025-12/69576_1.jpeg	426.7 KiB	218.7 KiB
CERN levels up with new superconducting karts Engineering News 1 April, 2026 `carousel-cern-item.owl-item > div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--5`	/sites/default/files/styles/large/public/2026-04/Kart-144...	237.5 KiB	212.9 KiB
Neutral currents `div.component-row__row > div.component-row__column > div.box-effects-wrapper > div#preview-card--24`	home.cern/sites/default/files/2025-12/60100_2.jpeg	300.3 KiB	202.0 KiB
CERN and the environment `div#explore-cern > div.component-row__row > div.component-row__column > div#preview-card--11`	home.cern/sites/default/files/2025-12/OPEN-PHO-CIVIL-2023-001-6_0_1.jpeg	150.1 KiB	105.6 KiB
ATLAS sets record limits on Higgs boson’s sel... Physics News 22 April, 2026 `carousel-cern-item.owl-item > div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card`	/sites/default/files/styles/large/public/2026-04/ATLAS-Ev...	100.9 KiB	84.2 KiB
ATLAS acts as a cosmic-ray laboratory Physics News 21 April, 2026 `carousel-cern-item.owl-item > div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--2`	/sites/default/files/styles/large/public/2026-04/ATLAS_co...	100.1 KiB	79.0 KiB
CMS strengthens the case for toponium Physics News 25 March, 2026 `carousel-cern-item.owl-item > div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--6`	/sites/default/files/styles/large/public/2026-03/Toponium...	91.8 KiB	70.7 KiB
Take an immersive tour of CERN's accelerators... `div.component-row__row > div.component-row__column > div.box-effects-wrapper > div#preview-card--9`	home.cern/sites/default/files/2025-12/Screenshot-vitual-tour_1.jpg	92.2 KiB	61.9 KiB
CMS looks deep inside quarks Physics News 16 April, 2026 `carousel-cern-item.owl-item > div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--3`	/sites/default/files/styles/large/public/2026-04/collisio...	62.6 KiB	41.5 KiB
home `div.site-info > div.site-info__logo > a > img`	home.cern/sites/default/files/logo/cern-logo.png	19.6 KiB	17.2 KiB
The Large Hadron Collider `div.component-row__row > div.component-row__column > div.box-effects-wrapper > div#preview-card--20`	home.cern/sites/default/files/2025-12/CERN-AC-0911188-01_2.jpg	45.3 KiB	11.0 KiB
Explore CERN's educational resources `div.component-row__row > div.component-row__column > div.box-effects-wrapper > div#preview-card--10`	/sites/default/files/2025-12/Artist Rasheedah Phillips fr...	263.8 KiB	10.6 KiB
The Higgs boson `div.component-row__row > div.component-row__column > div.box-effects-wrapper > div#preview-card--19`	home.cern/sites/default/files/2025-12/ATLAS-PHO-EVENTS-2014-010-1_1.jpg	43.2 KiB	5.7 KiB
CERN to host Europe’s flagship open access pu... At CERN News 26 March, 2026 `carousel-cern-item.owl-item > div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--3`	/sites/default/files/styles/large/public/2026-03/Mosaic_s...	32.1 KiB	4.1 KiB

Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading

Why this matters

Performance issues directly impact user engagement and conversion rates.

lhId: page-1-DIV

nodeLabel: div.owl-stage > div.owl-item > div.header-block > div.background-component

path: 1,HTML,1,BODY,4,MAIN,1,DIV,0,DIV,0,DIV,2,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,2,DIV,0,DIV,2,DIV

selector: div.owl-stage > div.owl-item > div.header-block > div.background-component

snippet: <div class="background-component background__image" style="">

HTTP/2 and HTTP/3 offer many benefits over HTTP/1.1, such as multiplexing. Learn more about using modern HTTP.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Protocol
home.cern/	http/1.1
home.cern/modules/custom/cern-loading/css/cern_loading.css?tckkx1	http/1.1
framework.web.cern.ch/framework/3.0/js/owlcarousel/css/owl.carousel.css	http/1.1
framework.web.cern.ch/framework/3.0/js/owlcarousel/css/owl.theme.default.css	http/1.1
home.cern/core/misc/components/progress.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/align.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/fieldgroup.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/container-inline.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/clearfix.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/details.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/hidden.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/item-list.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/js.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/nowrap.module.css?tckkx1	http/1.1
/core/modules/system/css/components/position-container.mo...	http/1.1
home.cern/core/modules/system/css/components/reset-appearance.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/resize.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/system-status-counter.css?tckkx1	http/1.1
/core/modules/system/css/components/system-status-report-...	http/1.1
/core/modules/system/css/components/system-status-report-...	http/1.1
home.cern/core/modules/system/css/components/tablesort.module.css?tckkx1	http/1.1
home.cern/modules/custom/cern-toolbar/assets/css/screen.css?tckkx1	http/1.1
home.cern/modules/custom/cern-toolbar/assets/css/cookieconsent.css?tckkx1	http/1.1
/modules/custom/cern-components/patterns/molecules/agenda...	http/1.1
/modules/custom/cern-components/patterns/atoms/background...	http/1.1
/modules/custom/cern-components/patterns/molecules/header...	http/1.1
/modules/custom/cern-components/patterns/molecules/header...	http/1.1
/modules/custom/cern-components/patterns/molecules/margin...	http/1.1
/modules/custom/cern-components/patterns/molecules/menu/c...	http/1.1
/modules/custom/cern-components/patterns/molecules/previe...	http/1.1
/modules/custom/cern-components/patterns/molecules/row/cs...	http/1.1
home.cern/core/modules/views/css/views.module.css?tckkx1	http/1.1
home.cern/core/modules/layout_discovery/layouts/onecol/onecol.css?tckkx1	http/1.1
home.cern/modules/contrib/paragraphs/css/paragraphs.unpublished.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/base.css?tckkx1	http/1.1
home.cern/sites/default/files/color/cernpublic-ac827e9a/colors.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/layout.css?tckkx1	http/1.1
framework.web.cern.ch/framework/3.0/js/prism/prism.css	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/components/footer.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/components/header.css?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/css/components/pagi...	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/components/forms.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/components/fields.css?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/css/components/drop...	http/1.1
/sites/default/themes/custom/cernbase/css/components/prog...	http/1.1
/sites/default/themes/custom/cernbase/css/components/acco...	http/1.1
/sites/default/themes/custom/cernbase/css/components/soci...	http/1.1
framework.web.cern.ch/framework/3.0/js/colorbox/colorbox.css	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/theme.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/cookies.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/viewspage.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/views/faq-views.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/views/agenda-views.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/views/news-views.css?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/css/views/stories-v...	http/1.1
/sites/default/themes/custom/cernbase/css/views/resources...	http/1.1
/sites/default/themes/custom/cernbase/css/views/taxonomie...	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/views/search-views.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/views/common-views.css?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/css/views/generic-v...	http/1.1
home.cern/sites/default/themes/custom/cernpublic/css/layout.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernpublic/css/overrides.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernpublic/css/header.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernpublic/css/views.css?tckkx1	http/1.1
framework.web.cern.ch/framework/3.0/images/loader.gif	http/1.1
home.cern/sites/default/files/logo/cern-logo.png	http/1.1
home.cern/core/assets/vendor/jquery/jquery.min.js?v=3.7.1	http/1.1
home.cern/core/assets/vendor/underscore/underscore-min.js?v=1.13.7	http/1.1
home.cern/core/assets/vendor/once/once.min.js?v=1.0.1	http/1.1
/sites/default/files/languages/en_p5SjUX5jHQqdSjFPWYikWHz...	http/1.1
home.cern/core/misc/drupalSettingsLoader.js?v=10.4.5	http/1.1
home.cern/core/misc/drupal.js?v=10.4.5	http/1.1
home.cern/core/misc/drupal.init.js?v=10.4.5	http/1.1
home.cern/core/assets/vendor/tabbable/index.umd.min.js?v=6.2.0	http/1.1
home.cern/core/misc/progress.js?v=10.4.5	http/1.1
home.cern/themes/contrib/bootstrap/js/misc/progress.js?tckkx1	http/1.1
home.cern/core/assets/vendor/loadjs/loadjs.min.js?v=4.3.0	http/1.1
home.cern/core/misc/debounce.js?v=10.4.5	http/1.1
home.cern/core/misc/announce.js?v=10.4.5	http/1.1
home.cern/core/misc/message.js?v=10.4.5	http/1.1
home.cern/themes/contrib/bootstrap/js/misc/message.js?tckkx1	http/1.1
home.cern/core/misc/ajax.js?v=10.4.5	http/1.1
home.cern/themes/contrib/bootstrap/js/misc/ajax.js?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/sass/bootstrap/java...	http/1.1
home.cern/themes/contrib/bootstrap/js/drupal.bootstrap.js?tckkx1	http/1.1
home.cern/themes/contrib/bootstrap/js/attributes.js?tckkx1	http/1.1
home.cern/themes/contrib/bootstrap/js/theme.js?tckkx1	http/1.1
home.cern/themes/contrib/bootstrap/js/popover.js?tckkx1	http/1.1
home.cern/themes/contrib/bootstrap/js/tooltip.js?tckkx1	http/1.1
home.cern/modules/custom/cern-loading/js/cern_loading.js?tckkx1	http/1.1
home.cern/modules/custom/cern-toolbar/assets/js/cern_toolbar.js?v=1.x	http/1.1
framework.web.cern.ch/framework/3.0/js/prism/prism.js	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/cernbase.js?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/js/components/socia...	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/components/footer.js?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/views/agenda-views.js?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/views/faq-views.js?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/views/news-views.js?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/js/views/resources-...	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/views/stories-views.js?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/js/views/taxonomies...	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/views/search-views.js?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/views/common-views.js?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/box-effects.js?tckkx1	http/1.1
framework.web.cern.ch/framework/3.0/js/colorbox/jquery.colorbox-min.js	http/1.1
framework.web.cern.ch/framework/3.0/js/scroll-magic/ScrollMagic.min.js	http/1.1
framework.web.cern.ch/framework/3.0/js/scroll-magic/text-effects.js	http/1.1
framework.web.cern.ch/framework/3.0/js/owlcarousel/js/owl.carousel.js	http/1.1
framework.web.cern.ch/framework/3.0/js/owlcarousel/js/owl.carousel2.thumbs.js	http/1.1
home.cern/sites/default/themes/custom/cernpublic/js/views_carousel.js?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernpublic/js/anchor-fix.js?tckkx1	http/1.1
home.cern/sites/default/modules/mathjax/js/config.js?v=10.4.5	http/1.1
home.cern/libraries/MathJax/MathJax.js?config=TeX-AMS-MML_HTMLorMML	http/1.1
home.cern/sites/default/modules/mathjax/js/setup.js?v=10.4.5	http/1.1
home.cern/modules/contrib/matomo/js/matomo.js?v=10.4.5	http/1.1
/modules/custom/cern-components/patterns/atoms/background...	http/1.1
/modules/custom/cern-components/patterns/molecules/header...	http/1.1
/modules/custom/cern-components/patterns/molecules/menu/j...	http/1.1
/modules/custom/cern-components/patterns/molecules/previe...	http/1.1
/modules/custom/cern-components/patterns/molecules/row/js...	http/1.1
home.cern/modules/custom/cern-loading/images/loader.gif	http/1.1
home.cern/modules/custom/cern-toolbar/assets/img/toolbarsprite.png	http/1.1
/sites/default/files/styles/large/public/2026-04/ATLAS-Ev...	http/1.1
/sites/default/files/styles/large/public/2026-04/ATLAS_co...	http/1.1
/sites/default/files/styles/large/public/2026-04/IMG_7455...	http/1.1
/sites/default/files/styles/large/public/2026-04/collisio...	http/1.1
/sites/default/files/styles/large/public/2026-03/Image_Ch...	http/1.1
home.cern/sites/default/files/2026-04/55182696113-0c4398702d-o-2_0.jpg	http/1.1
/sites/default/files/styles/large/public/2026-04/Kart-144...	http/1.1
/sites/default/files/styles/large/public/2026-03/Mosaic_s...	http/1.1
/sites/default/files/styles/large/public/2026-03/Toponium...	http/1.1
home.cern/sites/default/files/2025-12/202310-230_50_2_1.jpg	http/1.1
home.cern/sites/default/files/2025-12/Screenshot-vitual-tour_1.jpg	http/1.1
/sites/default/files/2025-12/Artist Rasheedah Phillips fr...	http/1.1
home.cern/sites/default/files/2025-12/OPEN-PHO-CIVIL-2023-001-6_0_1.jpeg	http/1.1
home.cern/sites/default/files/2025-12/CERN-EX-1212264-01_0_1.jpg	http/1.1
home.cern/sites/default/files/2025-12/ATLAS-PHO-EVENTS-2014-010-1_1.jpg	http/1.1
home.cern/sites/default/files/2025-12/CERN-AC-0911188-01_2.jpg	http/1.1
home.cern/sites/default/files/2025-12/CERN-EX-23296-1_1.jpg	http/1.1
home.cern/sites/default/files/2025-12/CERN-GE-9407011-31_1.jpg	http/1.1
home.cern/sites/default/files/2025-12/69576_1.jpeg	http/1.1
home.cern/sites/default/files/2025-12/60100_2.jpeg	http/1.1
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/regular.woff2	http/1.1
framework.web.cern.ch/framework/3.0/fonts/open-sans/bold.woff2	http/1.1
framework.web.cern.ch/framework/3.0/fonts/cern/cern.woff2	http/1.1
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/semibold.woff2	http/1.1
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/light.woff2	http/1.1
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/bold.woff2	http/1.1
home.cern/sites/default/files/2026-04/g2-experiment_1.png	http/1.1
home.cern/sites/default/files/2026-04/Toponium.png	http/1.1
home.cern/sites/default/files/2026-04/Antimatter-3.png	http/1.1
home.cern/sites/default/themes/custom/cernpublic/favicon.ico	http/1.1

Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.

Why this matters

Performance issues directly impact user engagement and conversion rates.

description: [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints help the browser establish a connection earlier in the page load, saving time when the first request for that origin is made. The following are the origins that the page preconnected to.

title: Preconnected origins

value: no origins were preconnected

description: Add [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints to your most important origins, but try to use no more than 4.

title: Preconnect candidates

Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Transfer Size	Duration
home.cern/sites/default/themes/custom/cernpublic/css/blocks.css?tckkx1	0 B	152 ms
home.cern/sites/default/themes/custom/cernpublic/css/views.css?tckkx1	1.1 KiB	152 ms
/sites/default/themes/custom/cernbase/css/views/generic-v...	4.0 KiB	302 ms
home.cern/sites/default/themes/custom/cernpublic/css/layout.css?tckkx1	1.6 KiB	152 ms
home.cern/sites/default/themes/custom/cernbase/css/views/common-views.css?tckkx1	967 B	152 ms
home.cern/sites/default/themes/custom/cernpublic/css/header.css?tckkx1	470 B	152 ms
home.cern/sites/default/themes/custom/cernpublic/css/overrides.css?tckkx1	688 B	152 ms
home.cern/sites/default/themes/custom/cernbase/css/views/search-views.css?tckkx1	1.6 KiB	152 ms
/sites/default/themes/custom/cernbase/css/views/stories-v...	750 B	152 ms
/sites/default/themes/custom/cernbase/css/views/resources...	3.2 KiB	302 ms
home.cern/sites/default/themes/custom/cernbase/css/views/news-views.css?tckkx1	3.2 KiB	302 ms
home.cern/sites/default/themes/custom/cernbase/css/views/agenda-views.css?tckkx1	3.5 KiB	302 ms
/sites/default/themes/custom/cernbase/css/views/taxonomie...	1.6 KiB	152 ms
home.cern/sites/default/themes/custom/cernbase/css/views/faq-views.css?tckkx1	1.8 KiB	152 ms
home.cern/sites/default/themes/custom/cernbase/css/theme.css?tckkx1	5.6 KiB	302 ms
/sites/default/themes/custom/cernbase/css/components/acco...	860 B	152 ms
home.cern/sites/default/themes/custom/cernbase/css/viewspage.css?tckkx1	477 B	152 ms
home.cern/sites/default/themes/custom/cernbase/css/cookies.css?tckkx1	1008 B	152 ms
/sites/default/themes/custom/cernbase/css/components/soci...	946 B	152 ms
/sites/default/themes/custom/cernbase/css/components/prog...	1.0 KiB	152 ms
/sites/default/themes/custom/cernbase/css/components/pagi...	1.3 KiB	152 ms
home.cern/sites/default/themes/custom/cernbase/css/components/fields.css?tckkx1	970 B	152 ms
home.cern/sites/default/themes/custom/cernbase/css/components/forms.css?tckkx1	2.3 KiB	152 ms
/sites/default/themes/custom/cernbase/css/components/drop...	1.6 KiB	152 ms
home.cern/sites/default/themes/custom/cernbase/css/components/header.css?tckkx1	3.2 KiB	302 ms
home.cern/sites/default/themes/custom/cernbase/css/components/footer.css?tckkx1	1.8 KiB	152 ms
home.cern/sites/default/files/color/cernpublic-ac827e9a/colors.css?tckkx1	5.8 KiB	452 ms
home.cern/sites/default/themes/custom/cernbase/css/layout.css?tckkx1	3.0 KiB	302 ms
home.cern/modules/contrib/paragraphs/css/paragraphs.unpublished.css?tckkx1	314 B	152 ms
home.cern/sites/default/themes/custom/cernbase/css/base.css?tckkx1	23.1 KiB	1.4 s
home.cern/core/modules/layout_discovery/layouts/onecol/onecol.css?tckkx1	374 B	152 ms
home.cern/core/modules/views/css/views.module.css?tckkx1	692 B	152 ms
/modules/custom/cern-components/patterns/molecules/menu/c...	5.0 KiB	302 ms
/modules/custom/cern-components/patterns/molecules/margin...	438 B	152 ms
/modules/custom/cern-components/patterns/molecules/previe...	2.8 KiB	152 ms
/modules/custom/cern-components/patterns/molecules/row/cs...	2.3 KiB	152 ms
/modules/custom/cern-components/patterns/molecules/header...	1.1 KiB	152 ms
/modules/custom/cern-components/patterns/molecules/header...	2.9 KiB	302 ms
framework.web.cern.ch/framework/3.0/js/owlcarousel/css/owl.theme.default.css	949 B	754 ms
framework.web.cern.ch/framework/3.0/js/prism/prism.css	2.3 KiB	754 ms
framework.web.cern.ch/framework/3.0/js/colorbox/colorbox.css	1.5 KiB	754 ms
framework.web.cern.ch/framework/3.0/js/owlcarousel/css/owl.carousel.css	1.5 KiB	754 ms
/core/modules/system/css/components/system-status-report-...	513 B	152 ms
/modules/custom/cern-components/patterns/atoms/background...	844 B	152 ms
home.cern/modules/custom/cern-toolbar/assets/css/cookieconsent.css?tckkx1	781 B	152 ms
/modules/custom/cern-components/patterns/molecules/agenda...	2.6 KiB	152 ms
home.cern/modules/custom/cern-toolbar/assets/css/screen.css?tckkx1	2.0 KiB	152 ms
home.cern/core/modules/system/css/components/tablesort.module.css?tckkx1	623 B	152 ms
home.cern/core/modules/system/css/components/system-status-counter.css?tckkx1	1023 B	152 ms
/core/modules/system/css/components/system-status-report-...	815 B	152 ms
home.cern/core/modules/system/css/components/resize.module.css?tckkx1	528 B	152 ms
home.cern/core/modules/system/css/components/reset-appearance.module.css?tckkx1	507 B	152 ms
/core/modules/system/css/components/position-container.mo...	352 B	152 ms
home.cern/core/modules/system/css/components/nowrap.module.css?tckkx1	353 B	152 ms
home.cern/core/modules/system/css/components/js.module.css?tckkx1	920 B	152 ms
home.cern/core/modules/system/css/components/details.module.css?tckkx1	385 B	152 ms
home.cern/core/modules/system/css/components/hidden.module.css?tckkx1	955 B	152 ms
home.cern/core/modules/system/css/components/item-list.module.css?tckkx1	545 B	152 ms
home.cern/core/modules/system/css/components/clearfix.module.css?tckkx1	565 B	452 ms
home.cern/core/modules/system/css/components/container-inline.module.css?tckkx1	533 B	452 ms
home.cern/core/modules/system/css/components/align.module.css?tckkx1	742 B	452 ms
home.cern/core/modules/system/css/components/fieldgroup.module.css?tckkx1	352 B	452 ms
home.cern/core/misc/components/progress.module.css?tckkx1	1.1 KiB	452 ms
home.cern/modules/custom/cern-loading/css/cern_loading.css?tckkx1	453 B	152 ms

These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.

Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric.

Why this matters

Performance issues directly impact user engagement and conversion rates.

TTI

The maximum potential First Input Delay that your users could experience is the duration of the longest task. Learn more about the Maximum Potential First Input Delay metric.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Diagnostics

Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 22.1 KiB

URL	Transfer Size	Est Savings
home.cern/sites/default/themes/custom/cernbase/css/base.css?tckkx1	22.8 KiB	22.1 KiB

Consider reducing the time spent parsing, compiling and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to minimize main-thread work

Why this matters

Performance issues directly impact user engagement and conversion rates.

Category	Time Spent
Other	869 ms
Script Evaluation	708 ms
Style & Layout	402 ms
Parse HTML & CSS	147 ms
Script Parsing & Compilation	83 ms
Rendering	45 ms
Garbage Collection	18 ms

Minifying CSS files can reduce network payload sizes. Learn how to minify CSS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 4.3 KiB

URL	Transfer Size	Est Savings
home.cern/sites/default/themes/custom/cernbase/css/base.css?tckkx1	23.1 KiB	4.3 KiB

Minifying JavaScript files can reduce payload sizes and script parse time. Learn how to minify JavaScript.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 26.9 KiB

URL	Transfer Size	Est Savings
home.cern/core/misc/ajax.js?v=10.4.5	17.0 KiB	11.9 KiB
framework.web.cern.ch/framework/3.0/js/owlcarousel/js/owl.carousel.js	18.5 KiB	7.2 KiB
home.cern/core/misc/drupal.js?v=10.4.5	6.1 KiB	4.8 KiB
home.cern/themes/contrib/bootstrap/js/drupal.bootstrap.js?tckkx1	4.9 KiB	2.9 KiB

Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Transfer Size
home.cern/sites/default/files/2026-04/Antimatter-3.png	5.0 MiB
home.cern/sites/default/files/2026-04/g2-experiment_1.png	4.7 MiB
home.cern/sites/default/files/2026-04/Toponium.png	1.3 MiB
home.cern/sites/default/files/2025-12/202310-230_50_2_1.jpg	1.1 MiB
home.cern/sites/default/files/2026-04/55182696113-0c4398702d-o-2_0.jpg	677.0 KiB
framework.web.cern.ch/framework/3.0/images/loader.gif	512.8 KiB
home.cern/modules/custom/cern-loading/images/loader.gif	512.7 KiB
home.cern/sites/default/files/2025-12/69576_1.jpeg	427.0 KiB
home.cern/sites/default/files/2025-12/60100_2.jpeg	300.6 KiB
/sites/default/files/2025-12/Artist Rasheedah Phillips fr...	264.0 KiB

Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL
home `div.site-info > div.site-info__logo > a > img`	home.cern/sites/default/files/logo/cern-logo.png

More information about the performance of your application. These numbers don't directly affect the Performance score.

●Layout shift culprits

●Document request latency

●Optimize DOM size

●LCP breakdown

●Optimize viewport for mobile

●Reduce unused JavaScript

●JavaScript execution time 0.7 s

●Avoid long main-thread tasks 5 long tasks found

●Avoid non-composited animations 1 animated element found

●Page didn't prevent back/forward cache restoration

●Network Requests

●Network Round Trip Times 30 ms

●Server Backend Latencies 30 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Avoid multiple page redirects

●Initial server response time was short Root document took 70 ms

●Avoid large layout shifts 1 layout shift found

○INP breakdown

○User Timing marks and measures

Accessibility

These checks highlight opportunities to improve the accessibility of your web app. Automatic detection can only detect a subset of issues and does not guarantee the accessibility of your web app, so manual testing is also encouraged.

Contrast

Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Copyright `body.page-node-193099 > footer > div.copy-wrapper > a`

These are opportunities to improve the legibility of your content.

Navigation

Properly ordered headings that do not skip levels convey the semantic structure of the page, making it easier to navigate and understand when using assistive technologies. Learn more about heading order.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
ATLAS sets record limits on Higgs boson’s sel... `div.component-preview-cards__box_wrapper > div.component-preview-cards__box > div.preview-card__title > h3.standard-title`
Plan your CERN visit `div.component-preview-cards__box_wrapper > div.component-preview-cards__box > div.preview-card__title > h3`
Axiverse Lampposts `div.agenda-box-pattern > div.agenda-box-pattern__box-wrapper > div.agenda-box-link > h3`
The Higgs boson `div.component-preview-cards__box_wrapper > div.component-preview-cards__box > div.preview-card__title > h3`

These are opportunities to improve keyboard navigation in your application.

Names and labels

Link text (and alternate text for images, when used as links) that is discernible, unique, and focusable improves the navigation experience for screen reader users. Learn how to make links accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--2 > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--2 > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--3 > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--3 > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--2 > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--2 > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--4 > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--4 > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--5 > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--5 > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--3 > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--3 > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--6 > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--6 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--8 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--8 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--9 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--9 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--10 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--10 > a.box-link`
div.component-row__row > div.component-row__column > div#preview-card--11 > a.box-link `div.component-row__row > div.component-row__column > div#preview-card--11 > a.box-link`
div.component-row__row > div.component-row__column > div#preview-card--12 > a.box-link `div.component-row__row > div.component-row__column > div#preview-card--12 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--19 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--19 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--20 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--20 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--21 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--21 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--22 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--22 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--23 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--23 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--24 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--24 > a.box-link`

These are opportunities to improve the semantics of the controls in your application. This may enhance the experience for users of assistive technology, like a screen reader.

○Interactive controls are keyboard focusable

○Interactive elements indicate their purpose and state

○The page has a logical tab order

○Visual order on the page follows DOM order

○User focus is not accidentally trapped in a region

○The user's focus is directed to new content added to the page

○HTML5 landmark elements are used to improve navigation

○Offscreen content is hidden from assistive technology

○Custom controls have associated labels

○Custom controls have ARIA roles

●`[aria-*]` attributes match their roles

●`[aria-hidden="true"]` is not present on the document `<body>`

●`[role]`s have all required `[aria-*]` attributes

●`[role]` values are valid

●`[aria-*]` attributes have valid values

●`[aria-*]` attributes are valid and not misspelled

●Buttons have an accessible name

●Image elements have `[alt]` attributes

●`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.

●ARIA attributes are used as specified for the element's role

●`[aria-hidden="true"]` elements do not contain focusable descendents

●Elements use only permitted ARIA attributes

●Document has a `<title>` element

●`<html>` element has a `[lang]` attribute

●`<html>` element has a valid value for its `[lang]` attribute

●Links are distinguishable without relying on color.

●Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).

●List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements

●No element has a `[tabindex]` value greater than 0

●Touch targets have sufficient size and spacing.

●Document has a main landmark.

●Deprecated ARIA roles were not used

●Identical links have the same purpose.

○`[accesskey]` values are unique

○`button`, `link`, and `menuitem` elements have accessible names

○Elements with `role="dialog"` or `role="alertdialog"` have accessible names.

○ARIA input fields have accessible names

○ARIA `meter` elements have accessible names

○ARIA `progressbar` elements have accessible names

○Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.

○`[role]`s are contained by their required parent element

○Elements with the `role=text` attribute do not have focusable descendents.

○ARIA toggle fields have accessible names

○ARIA `tooltip` elements have accessible names

○ARIA `treeitem` elements have accessible names

○The page contains a heading, skip link, or landmark region

○`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.

○Definition list items are wrapped in `<dl>` elements

○ARIA IDs are unique

○No form fields have multiple labels

○`<frame>` or `<iframe>` elements have a title

○`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.

○Input buttons have discernible text.

○`<input type="image">` elements have `[alt]` text

○Form elements have associated labels

○The document does not use `<meta http-equiv="refresh">`

○`<object>` elements have alternate text

○Select elements have associated label elements.

○Skip links are focusable.

○Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.

○`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.

○`[lang]` attributes have a valid value

○`<video>` elements contain a `<track>` element with `[kind="captions"]`

○Tables have different content in the summary attribute and `<caption>`.

○All heading elements contain content.

○Uses ARIA roles only on compatible elements

○Image elements do not have `[alt]` attributes that are redundant text.

○Elements with visible text labels have matching accessible names.

○Tables use `<caption>` instead of cells with the `[colspan]` attribute to indicate a caption.

○`<td>` elements in a large `<table>` have one or more table headers.

Best Practices

General

Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more about this errors in console diagnostic audit

Why this matters

Performance issues directly impact user engagement and conversion rates.

Source	Description
home.cern/libraries/MathJax/MathJax.js?config=TeX-AMS-MML_HTMLorMML	`Failed to load resource: the server responded with a status of 500 (500 Service unavailable (with message))`
home.cern/	`Refused to apply style from 'https://home.cern/sites/default/themes/custom/cernpublic/css/blocks.css?tckkx1' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled.`

●Uses HTTPS

●Avoids deprecated APIs

●Avoids third-party cookies

●Allows users to paste into input fields

●Avoids requesting the geolocation permission on page load

●Avoids requesting the notification permission on page load

●Displays images with correct aspect ratio

●Serves images with appropriate resolution

●Page has the HTML doctype

●Properly defines charset

●No issues in the `Issues` panel in Chrome Devtools

●Ensure CSP is effective against XSS attacks

●Use a strong HSTS policy

●Ensure proper origin isolation with COOP

●Mitigate DOM-based XSS with Trusted Types

●Detected JavaScript libraries

●Page has valid source maps

○Redirects HTTP traffic to HTTPS

○Mitigate clickjacking with XFO or CSP

100

SEO

These checks ensure that your page is following basic search engine optimization advice. There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals. Learn more about Google Search Essentials.

○Structured data is valid

●Page isn’t blocked from indexing

●Document has a `<title>` element

●Document has a meta description

●Page has successful HTTP status code

●Links have descriptive text

●Links are crawlable

●robots.txt is valid

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`

●Document has a valid `rel=canonical`

Lighthouse Scores

Industry-standard audits powered by Google Lighthouse. — Desktop

Performance

Accessibility

Best Practices

100

SEO

Core Web Vitals

Key metrics that affect user experience. — Desktop

First Contentful Paint First Contentful Paint — how long until the browser renders the first piece of content. Under 1.8s is good.

814 ms

Largest Contentful Paint Largest Contentful Paint — how long until the largest visible element loads. Under 2.5s is good.

14.82 s

Total Blocking Time Total Blocking Time — total time the main thread was blocked, preventing user input. Under 200ms is good.

51 ms

Cumulative Layout Shift Cumulative Layout Shift — measures visual stability. How much the page layout shifts during loading. Under 0.1 is good.

0.547

Speed Index Speed Index — how quickly content is visually displayed during load. Under 3.4s is good.

1.40 s

Time to Interactive Time to Interactive — how long until the page is fully interactive and responds to user input. Under 3.8s is good.

14.88 s

Detailed Report

Audit breakdown by category with detailed findings.

Performance

Insights

Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Why this matters

Shipping ES5 transpiled code to modern browsers wastes bytes — every user with an evergreen browser pays for compatibility you don't need.

Learn more ▾

Source: Google web.dev / Lighthouse

3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.

Why this matters

Performance issues directly impact user engagement and conversion rates.

A long cache lifetime can speed up repeat visits to your page. Learn more about caching.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Request	Cache TTL	Transfer Size
/sites/default/files/styles/large/public/2026-04/Kart-144...	0.0 ms	237.7 KiB
/sites/default/files/styles/large/public/2026-04/ATLAS-Ev...	0.0 ms	101.1 KiB
/sites/default/files/styles/large/public/2026-04/ATLAS_co...	0.0 ms	100.3 KiB
/sites/default/files/styles/large/public/2026-03/Toponium...	0.0 ms	91.9 KiB
/sites/default/files/styles/large/public/2026-04/collisio...	0.0 ms	62.8 KiB
/sites/default/files/styles/large/public/2026-03/Mosaic_s...	0.0 ms	32.3 KiB
/sites/default/files/styles/large/public/2026-04/IMG_7455...	0.0 ms	30.5 KiB
/sites/default/files/styles/large/public/2026-03/Image_Ch...	0.0 ms	16.7 KiB

Layout shifts occur when elements move absent any user interaction. Investigate the causes of layout shifts, such as elements being added, removed, or their fonts changing as the page loads.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:node label:Element subItemsHeading:map[key:extra] valueType:node] map[granularity:0.001 key:score label:Layout shift score subItemsHeading:map[key:cause valueType:text] valueType:numeric]]

items: [map[node:map[type:text value:Total] score:0.5469399999999999] map[node:map[boundingRect:map[bottom:3514 height:3474 left:0 right:1350 top:40 width:1350] lhId:page-30-BODY nodeLabel:body.page-node-193099 path:1,HTML,1,BODY selector:body.page-node-193099 snippet:<body class="page-node-193099 page-node-type-landing_page cern-theme-on path-frontpage …"> type:node] score:0.542963 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:3223 height:40 left:105 right:145 top:3183 width:40] lhId:page-21-IMG nodeLabel:Facebook icon path:1,HTML,1,BODY,5,FOOTER,0,DIV,0,DIV,0,DIV,0,SECTION,0,DIV,1,DIV,0,P,0,A,0,IMG selector:div.field > p > a > img snippet:<img alt="Facebook icon" data-entity-type="file" data-entity-uuid="5da97013-d976-42e3-aaf3-c2cdf2683c3d" height="40" src="/sites/default/files/inline-images/lburdych/Facebook.png" width="40" loading="lazy"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:1001 height:60 left:0 right:1350 top:941 width:1350] lhId:page-31-DIV nodeLabel:div.layout > div.layout__region > div.field > div.field--item path:1,HTML,1,BODY,4,MAIN,1,DIV,0,DIV,0,DIV,2,DIV,0,DIV,0,DIV,1,DIV selector:div.layout > div.layout__region > div.field > div.field--item snippet:<div class="field--item"> type:node] score:0.001516 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:3223 height:40 left:105 right:145 top:3183 width:40] lhId:page-21-IMG nodeLabel:Facebook icon path:1,HTML,1,BODY,5,FOOTER,0,DIV,0,DIV,0,DIV,0,SECTION,0,DIV,1,DIV,0,P,0,A,0,IMG selector:div.field > p > a > img snippet:<img alt="Facebook icon" data-entity-type="file" data-entity-uuid="5da97013-d976-42e3-aaf3-c2cdf2683c3d" height="40" src="/sites/default/files/inline-images/lburdych/Facebook.png" width="40" loading="lazy"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:1001 height:60 left:0 right:1350 top:941 width:1350] lhId:page-31-DIV nodeLabel:div.layout > div.layout__region > div.field > div.field--item path:1,HTML,1,BODY,4,MAIN,1,DIV,0,DIV,0,DIV,2,DIV,0,DIV,0,DIV,1,DIV selector:div.layout > div.layout__region > div.field > div.field--item snippet:<div class="field--item"> type:node] score:0.000743 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:3223 height:40 left:105 right:145 top:3183 width:40] lhId:page-21-IMG nodeLabel:Facebook icon path:1,HTML,1,BODY,5,FOOTER,0,DIV,0,DIV,0,DIV,0,SECTION,0,DIV,1,DIV,0,P,0,A,0,IMG selector:div.field > p > a > img snippet:<img alt="Facebook icon" data-entity-type="file" data-entity-uuid="5da97013-d976-42e3-aaf3-c2cdf2683c3d" height="40" src="/sites/default/files/inline-images/lburdych/Facebook.png" width="40" loading="lazy"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:1001 height:60 left:0 right:1350 top:941 width:1350] lhId:page-31-DIV nodeLabel:div.layout > div.layout__region > div.field > div.field--item path:1,HTML,1,BODY,4,MAIN,1,DIV,0,DIV,0,DIV,2,DIV,0,DIV,0,DIV,1,DIV selector:div.layout > div.layout__region > div.field > div.field--item snippet:<div class="field--item"> type:node] score:0.000279 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:3223 height:40 left:105 right:145 top:3183 width:40] lhId:page-21-IMG nodeLabel:Facebook icon path:1,HTML,1,BODY,5,FOOTER,0,DIV,0,DIV,0,DIV,0,SECTION,0,DIV,1,DIV,0,P,0,A,0,IMG selector:div.field > p > a > img snippet:<img alt="Facebook icon" data-entity-type="file" data-entity-uuid="5da97013-d976-42e3-aaf3-c2cdf2683c3d" height="40" src="/sites/default/files/inline-images/lburdych/Facebook.png" width="40" loading="lazy"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:1001 height:60 left:0 right:1350 top:941 width:1350] lhId:page-31-DIV nodeLabel:div.layout > div.layout__region > div.field > div.field--item path:1,HTML,1,BODY,4,MAIN,1,DIV,0,DIV,0,DIV,2,DIV,0,DIV,0,DIV,1,DIV selector:div.layout > div.layout__region > div.field > div.field--item snippet:<div class="field--item"> type:node] score:0.000192 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:3223 height:40 left:105 right:145 top:3183 width:40] lhId:page-21-IMG nodeLabel:Facebook icon path:1,HTML,1,BODY,5,FOOTER,0,DIV,0,DIV,0,DIV,0,SECTION,0,DIV,1,DIV,0,P,0,A,0,IMG selector:div.field > p > a > img snippet:<img alt="Facebook icon" data-entity-type="file" data-entity-uuid="5da97013-d976-42e3-aaf3-c2cdf2683c3d" height="40" src="/sites/default/files/inline-images/lburdych/Facebook.png" width="40" loading="lazy"> type:node]]] type:subitems]]]

Consider setting font-display to swap or optional to ensure text is consistently visible. swap can be further optimized to mitigate layout shifts with font metric overrides.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Est Savings
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/regular.woff2	70 ms
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/light.woff2	70 ms
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/bold.woff2	70 ms
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/semibold.woff2	65 ms
framework.web.cern.ch/framework/3.0/fonts/open-sans/bold.woff2	60 ms
framework.web.cern.ch/framework/3.0/fonts/cern/cern.woff2	60 ms

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:source label:Top function call valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]

items: [map[reflowTime:34.517 source:map[column:22 line:19 type:source-location url:https://home.cern/core/misc/drupal.init.js?v=10.4.5 urlProvider:network]]]

headings: [map[key:source label:Source valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]

items: [map[reflowTime:22.521 source:map[column:79427 line:1 type:source-location url:https://home.cern/core/assets/vendor/jquery/jquery.min.js?v=3.7.1 urlProvider:network]] map[reflowTime:10.707 source:map[column:49615 line:1 type:source-location url:https://home.cern/core/assets/vendor/jquery/jquery.min.js?v=3.7.1 urlProvider:network]] map[reflowTime:0.396 source:map[column:50335 line:1 type:source-location url:https://home.cern/core/assets/vendor/jquery/jquery.min.js?v=3.7.1 urlProvider:network]] map[reflowTime:0.191 source:map[column:50393 line:1 type:source-location url:https://home.cern/core/assets/vendor/jquery/jquery.min.js?v=3.7.1 urlProvider:network]] map[reflowTime:0.199 source:map[column:50457 line:1 type:source-location url:https://home.cern/core/assets/vendor/jquery/jquery.min.js?v=3.7.1 urlProvider:network]] map[reflowTime:0.147 source:map[column:49637 line:1 type:source-location url:https://home.cern/core/assets/vendor/jquery/jquery.min.js?v=3.7.1 urlProvider:network]] map[reflowTime:0.356 source:map[column:51395 line:1 type:source-location url:https://home.cern/core/assets/vendor/jquery/jquery.min.js?v=3.7.1 urlProvider:network]]]

Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL	Resource Size	Est Savings
div.owl-stage > div.owl-item > div.header-block > div.background-component `div.owl-stage > div.owl-item > div.header-block > div.background-component`	home.cern/sites/default/files/2026-04/Antimatter-3.png	5.0 MiB	4.0 MiB
div.owl-stage > div.owl-item > div.header-block > div.background-component `div.owl-stage > div.owl-item > div.header-block > div.background-component`	home.cern/sites/default/files/2026-04/g2-experiment_1.png	4.7 MiB	3.7 MiB
Plan your CERN visit `div.component-row__row > div.component-row__column > div.box-effects-wrapper > div#preview-card--8`	home.cern/sites/default/files/2025-12/202310-230_50_2_1.jpg	1.1 MiB	868.3 KiB
body.page-node-193099 > div#cern-global-loading-layout `body.page-node-193099 > div#cern-global-loading-layout`	home.cern/modules/custom/cern-loading/images/loader.gif	512.4 KiB	338.2 KiB
div.owl-stage > div.owl-item > div.header-block > div.background-component `div.owl-stage > div.owl-item > div.header-block > div.background-component`	home.cern/sites/default/files/2026-04/Toponium.png	1.3 MiB	275.0 KiB
W and Z bosons `div.component-row__row > div.component-row__column > div.box-effects-wrapper > div#preview-card--23`	home.cern/sites/default/files/2025-12/69576_1.jpeg	426.7 KiB	218.7 KiB
CERN levels up with new superconducting karts Engineering News 1 April, 2026 `carousel-cern-item.owl-item > div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--5`	/sites/default/files/styles/large/public/2026-04/Kart-144...	237.5 KiB	212.9 KiB
Neutral currents `div.component-row__row > div.component-row__column > div.box-effects-wrapper > div#preview-card--24`	home.cern/sites/default/files/2025-12/60100_2.jpeg	300.3 KiB	202.0 KiB
CERN and the environment `div#explore-cern > div.component-row__row > div.component-row__column > div#preview-card--11`	home.cern/sites/default/files/2025-12/OPEN-PHO-CIVIL-2023-001-6_0_1.jpeg	150.1 KiB	105.6 KiB
ATLAS sets record limits on Higgs boson’s sel... Physics News 22 April, 2026 `carousel-cern-item.owl-item > div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card`	/sites/default/files/styles/large/public/2026-04/ATLAS-Ev...	100.9 KiB	84.2 KiB
ATLAS acts as a cosmic-ray laboratory Physics News 21 April, 2026 `carousel-cern-item.owl-item > div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--2`	/sites/default/files/styles/large/public/2026-04/ATLAS_co...	100.1 KiB	79.0 KiB
CMS strengthens the case for toponium Physics News 25 March, 2026 `carousel-cern-item.owl-item > div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--6`	/sites/default/files/styles/large/public/2026-03/Toponium...	91.8 KiB	70.7 KiB
Take an immersive tour of CERN's accelerators... `div.component-row__row > div.component-row__column > div.box-effects-wrapper > div#preview-card--9`	home.cern/sites/default/files/2025-12/Screenshot-vitual-tour_1.jpg	92.2 KiB	61.9 KiB
CMS looks deep inside quarks Physics News 16 April, 2026 `carousel-cern-item.owl-item > div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--3`	/sites/default/files/styles/large/public/2026-04/collisio...	62.6 KiB	41.5 KiB
X icon `div.field > p > a > img`	home.cern/sites/default/files/inline-images/lburdych/X.png	27.2 KiB	27.1 KiB
Instagram icon `div.field > p > a > img`	home.cern/sites/default/files/inline-images/lburdych/Instagram.png	25.7 KiB	25.6 KiB
home `div.site-info > div.site-info__logo > a > img`	home.cern/sites/default/files/logo/cern-logo.png	19.6 KiB	18.8 KiB
TikTok icon `div.field > p > a > img`	home.cern/sites/default/files/inline-images/lburdych/TikTok_0.png	18.8 KiB	18.6 KiB
Youtube icon `div.field > p > a > img`	home.cern/sites/default/files/inline-images/lburdych/Youtube.png	18.0 KiB	17.9 KiB
LinkedIn icon `div.field > p > a > img`	home.cern/sites/default/files/inline-images/lburdych/LinkedIn.png	14.4 KiB	14.3 KiB
The Large Hadron Collider `div.component-row__row > div.component-row__column > div.box-effects-wrapper > div#preview-card--20`	home.cern/sites/default/files/2025-12/CERN-AC-0911188-01_2.jpg	45.3 KiB	11.0 KiB
Facebook icon `div.field > p > a > img`	home.cern/sites/default/files/inline-images/lburdych/Facebook.png	11.0 KiB	11.0 KiB
Explore CERN's educational resources `div.component-row__row > div.component-row__column > div.box-effects-wrapper > div#preview-card--10`	/sites/default/files/2025-12/Artist Rasheedah Phillips fr...	263.8 KiB	10.6 KiB
The Higgs boson `div.component-row__row > div.component-row__column > div.box-effects-wrapper > div#preview-card--19`	home.cern/sites/default/files/2025-12/ATLAS-PHO-EVENTS-2014-010-1_1.jpg	43.2 KiB	5.7 KiB
CERN to host Europe’s flagship open access pu... At CERN News 26 March, 2026 `carousel-cern-item.owl-item > div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--3`	/sites/default/files/styles/large/public/2026-03/Mosaic_s...	32.1 KiB	4.1 KiB

Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading

Why this matters

Performance issues directly impact user engagement and conversion rates.

lhId: page-1-DIV

nodeLabel: div.owl-stage > div.owl-item > div.header-block > div.background-component

path: 1,HTML,1,BODY,4,MAIN,1,DIV,0,DIV,0,DIV,2,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,2,DIV,0,DIV,2,DIV

selector: div.owl-stage > div.owl-item > div.header-block > div.background-component

snippet: <div class="background-component background__image" style="">

HTTP/2 and HTTP/3 offer many benefits over HTTP/1.1, such as multiplexing. Learn more about using modern HTTP.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Protocol
home.cern/	http/1.1
home.cern/modules/custom/cern-loading/css/cern_loading.css?tckkx1	http/1.1
framework.web.cern.ch/framework/3.0/js/owlcarousel/css/owl.carousel.css	http/1.1
framework.web.cern.ch/framework/3.0/js/owlcarousel/css/owl.theme.default.css	http/1.1
home.cern/core/misc/components/progress.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/align.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/fieldgroup.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/container-inline.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/clearfix.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/details.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/hidden.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/item-list.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/js.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/nowrap.module.css?tckkx1	http/1.1
/core/modules/system/css/components/position-container.mo...	http/1.1
home.cern/core/modules/system/css/components/reset-appearance.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/resize.module.css?tckkx1	http/1.1
home.cern/core/modules/system/css/components/system-status-counter.css?tckkx1	http/1.1
/core/modules/system/css/components/system-status-report-...	http/1.1
/core/modules/system/css/components/system-status-report-...	http/1.1
home.cern/core/modules/system/css/components/tablesort.module.css?tckkx1	http/1.1
home.cern/modules/custom/cern-toolbar/assets/css/screen.css?tckkx1	http/1.1
home.cern/modules/custom/cern-toolbar/assets/css/cookieconsent.css?tckkx1	http/1.1
/modules/custom/cern-components/patterns/molecules/agenda...	http/1.1
/modules/custom/cern-components/patterns/atoms/background...	http/1.1
/modules/custom/cern-components/patterns/molecules/header...	http/1.1
/modules/custom/cern-components/patterns/molecules/header...	http/1.1
/modules/custom/cern-components/patterns/molecules/margin...	http/1.1
/modules/custom/cern-components/patterns/molecules/menu/c...	http/1.1
/modules/custom/cern-components/patterns/molecules/previe...	http/1.1
/modules/custom/cern-components/patterns/molecules/row/cs...	http/1.1
home.cern/core/modules/views/css/views.module.css?tckkx1	http/1.1
home.cern/core/modules/layout_discovery/layouts/onecol/onecol.css?tckkx1	http/1.1
home.cern/modules/contrib/paragraphs/css/paragraphs.unpublished.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/base.css?tckkx1	http/1.1
home.cern/sites/default/files/color/cernpublic-ac827e9a/colors.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/layout.css?tckkx1	http/1.1
framework.web.cern.ch/framework/3.0/js/prism/prism.css	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/components/footer.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/components/header.css?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/css/components/pagi...	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/components/forms.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/components/fields.css?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/css/components/drop...	http/1.1
/sites/default/themes/custom/cernbase/css/components/prog...	http/1.1
/sites/default/themes/custom/cernbase/css/components/acco...	http/1.1
/sites/default/themes/custom/cernbase/css/components/soci...	http/1.1
framework.web.cern.ch/framework/3.0/js/colorbox/colorbox.css	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/theme.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/cookies.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/viewspage.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/views/faq-views.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/views/agenda-views.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/views/news-views.css?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/css/views/stories-v...	http/1.1
/sites/default/themes/custom/cernbase/css/views/resources...	http/1.1
/sites/default/themes/custom/cernbase/css/views/taxonomie...	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/views/search-views.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/css/views/common-views.css?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/css/views/generic-v...	http/1.1
home.cern/sites/default/themes/custom/cernpublic/css/layout.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernpublic/css/overrides.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernpublic/css/header.css?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernpublic/css/views.css?tckkx1	http/1.1
framework.web.cern.ch/framework/3.0/images/loader.gif	http/1.1
home.cern/sites/default/files/logo/cern-logo.png	http/1.1
home.cern/core/assets/vendor/jquery/jquery.min.js?v=3.7.1	http/1.1
home.cern/core/assets/vendor/underscore/underscore-min.js?v=1.13.7	http/1.1
home.cern/core/assets/vendor/once/once.min.js?v=1.0.1	http/1.1
/sites/default/files/languages/en_p5SjUX5jHQqdSjFPWYikWHz...	http/1.1
home.cern/core/misc/drupalSettingsLoader.js?v=10.4.5	http/1.1
home.cern/core/misc/drupal.js?v=10.4.5	http/1.1
home.cern/core/misc/drupal.init.js?v=10.4.5	http/1.1
home.cern/core/assets/vendor/tabbable/index.umd.min.js?v=6.2.0	http/1.1
home.cern/core/misc/progress.js?v=10.4.5	http/1.1
home.cern/themes/contrib/bootstrap/js/misc/progress.js?tckkx1	http/1.1
home.cern/core/assets/vendor/loadjs/loadjs.min.js?v=4.3.0	http/1.1
home.cern/core/misc/debounce.js?v=10.4.5	http/1.1
home.cern/core/misc/announce.js?v=10.4.5	http/1.1
home.cern/core/misc/message.js?v=10.4.5	http/1.1
home.cern/themes/contrib/bootstrap/js/misc/message.js?tckkx1	http/1.1
home.cern/core/misc/ajax.js?v=10.4.5	http/1.1
home.cern/themes/contrib/bootstrap/js/misc/ajax.js?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/sass/bootstrap/java...	http/1.1
home.cern/themes/contrib/bootstrap/js/drupal.bootstrap.js?tckkx1	http/1.1
home.cern/themes/contrib/bootstrap/js/attributes.js?tckkx1	http/1.1
home.cern/themes/contrib/bootstrap/js/theme.js?tckkx1	http/1.1
home.cern/themes/contrib/bootstrap/js/popover.js?tckkx1	http/1.1
home.cern/themes/contrib/bootstrap/js/tooltip.js?tckkx1	http/1.1
home.cern/modules/custom/cern-loading/js/cern_loading.js?tckkx1	http/1.1
home.cern/modules/custom/cern-toolbar/assets/js/cern_toolbar.js?v=1.x	http/1.1
framework.web.cern.ch/framework/3.0/js/prism/prism.js	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/cernbase.js?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/js/components/socia...	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/components/footer.js?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/views/agenda-views.js?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/views/faq-views.js?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/views/news-views.js?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/js/views/resources-...	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/views/stories-views.js?tckkx1	http/1.1
/sites/default/themes/custom/cernbase/js/views/taxonomies...	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/views/search-views.js?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/views/common-views.js?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernbase/js/box-effects.js?tckkx1	http/1.1
framework.web.cern.ch/framework/3.0/js/colorbox/jquery.colorbox-min.js	http/1.1
framework.web.cern.ch/framework/3.0/js/scroll-magic/ScrollMagic.min.js	http/1.1
framework.web.cern.ch/framework/3.0/js/scroll-magic/text-effects.js	http/1.1
framework.web.cern.ch/framework/3.0/js/owlcarousel/js/owl.carousel.js	http/1.1
framework.web.cern.ch/framework/3.0/js/owlcarousel/js/owl.carousel2.thumbs.js	http/1.1
home.cern/sites/default/themes/custom/cernpublic/js/views_carousel.js?tckkx1	http/1.1
home.cern/sites/default/themes/custom/cernpublic/js/anchor-fix.js?tckkx1	http/1.1
home.cern/sites/default/modules/mathjax/js/config.js?v=10.4.5	http/1.1
home.cern/libraries/MathJax/MathJax.js?config=TeX-AMS-MML_HTMLorMML	http/1.1
home.cern/sites/default/modules/mathjax/js/setup.js?v=10.4.5	http/1.1
home.cern/modules/contrib/matomo/js/matomo.js?v=10.4.5	http/1.1
/modules/custom/cern-components/patterns/atoms/background...	http/1.1
/modules/custom/cern-components/patterns/molecules/header...	http/1.1
/modules/custom/cern-components/patterns/molecules/menu/j...	http/1.1
/modules/custom/cern-components/patterns/molecules/previe...	http/1.1
/modules/custom/cern-components/patterns/molecules/row/js...	http/1.1
home.cern/modules/custom/cern-loading/images/loader.gif	http/1.1
/sites/default/files/styles/large/public/2026-04/ATLAS-Ev...	http/1.1
/sites/default/files/styles/large/public/2026-04/ATLAS_co...	http/1.1
/sites/default/files/styles/large/public/2026-04/IMG_7455...	http/1.1
/sites/default/files/styles/large/public/2026-04/collisio...	http/1.1
/sites/default/files/styles/large/public/2026-03/Image_Ch...	http/1.1
home.cern/sites/default/files/2026-04/55182696113-0c4398702d-o-2_0.jpg	http/1.1
/sites/default/files/styles/large/public/2026-04/Kart-144...	http/1.1
/sites/default/files/styles/large/public/2026-03/Mosaic_s...	http/1.1
/sites/default/files/styles/large/public/2026-03/Toponium...	http/1.1
home.cern/sites/default/files/2025-12/202310-230_50_2_1.jpg	http/1.1
home.cern/sites/default/files/2025-12/Screenshot-vitual-tour_1.jpg	http/1.1
/sites/default/files/2025-12/Artist Rasheedah Phillips fr...	http/1.1
home.cern/sites/default/files/2025-12/OPEN-PHO-CIVIL-2023-001-6_0_1.jpeg	http/1.1
home.cern/sites/default/files/2025-12/CERN-EX-1212264-01_0_1.jpg	http/1.1
home.cern/sites/default/files/2025-12/ATLAS-PHO-EVENTS-2014-010-1_1.jpg	http/1.1
home.cern/sites/default/files/2025-12/CERN-AC-0911188-01_2.jpg	http/1.1
home.cern/sites/default/files/2025-12/CERN-EX-23296-1_1.jpg	http/1.1
home.cern/sites/default/files/2025-12/CERN-GE-9407011-31_1.jpg	http/1.1
home.cern/sites/default/files/2025-12/69576_1.jpeg	http/1.1
home.cern/sites/default/files/2025-12/60100_2.jpeg	http/1.1
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/regular.woff2	http/1.1
framework.web.cern.ch/framework/3.0/fonts/open-sans/bold.woff2	http/1.1
framework.web.cern.ch/framework/3.0/fonts/cern/cern.woff2	http/1.1
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/semibold.woff2	http/1.1
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/light.woff2	http/1.1
framework.web.cern.ch/framework/3.0/fonts/sourcesanspro/bold.woff2	http/1.1
home.cern/sites/default/files/inline-images/lburdych/Facebook.png	http/1.1
home.cern/sites/default/files/inline-images/lburdych/Instagram.png	http/1.1
home.cern/sites/default/files/inline-images/lburdych/TikTok_0.png	http/1.1
home.cern/sites/default/files/inline-images/lburdych/X.png	http/1.1
home.cern/sites/default/files/inline-images/lburdych/LinkedIn.png	http/1.1
home.cern/sites/default/files/inline-images/lburdych/Youtube.png	http/1.1
home.cern/sites/default/files/2026-04/g2-experiment_1.png	http/1.1
home.cern/sites/default/files/2026-04/Toponium.png	http/1.1
home.cern/sites/default/files/2026-04/Antimatter-3.png	http/1.1
home.cern/sites/default/themes/custom/cernpublic/favicon.ico	http/1.1

Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.

Why this matters

Performance issues directly impact user engagement and conversion rates.

title: Preconnected origins

value: no origins were preconnected

description: Add [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints to your most important origins, but try to use no more than 4.

title: Preconnect candidates

Requests are blocking the page's initial render, which may delay LCP. Deferring or inlining can move these network requests out of the critical path.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Transfer Size	Duration
home.cern/sites/default/themes/custom/cernpublic/css/blocks.css?tckkx1	0 B
home.cern/sites/default/themes/custom/cernpublic/css/views.css?tckkx1	1.1 KiB
home.cern/sites/default/themes/custom/cernpublic/css/header.css?tckkx1	470 B
/sites/default/themes/custom/cernbase/css/views/generic-v...	4.0 KiB
home.cern/sites/default/themes/custom/cernpublic/css/overrides.css?tckkx1	688 B
home.cern/sites/default/themes/custom/cernpublic/css/layout.css?tckkx1	1.6 KiB
home.cern/sites/default/themes/custom/cernbase/css/views/common-views.css?tckkx1	967 B
/sites/default/themes/custom/cernbase/css/views/taxonomie...	1.6 KiB
home.cern/sites/default/themes/custom/cernbase/css/views/search-views.css?tckkx1	1.6 KiB
home.cern/sites/default/themes/custom/cernbase/css/views/news-views.css?tckkx1	3.2 KiB
home.cern/sites/default/themes/custom/cernbase/css/views/agenda-views.css?tckkx1	3.5 KiB
/sites/default/themes/custom/cernbase/css/views/stories-v...	750 B
/sites/default/themes/custom/cernbase/css/views/resources...	3.2 KiB
home.cern/sites/default/themes/custom/cernbase/css/views/faq-views.css?tckkx1	1.8 KiB
home.cern/sites/default/themes/custom/cernbase/css/viewspage.css?tckkx1	477 B
home.cern/sites/default/themes/custom/cernbase/css/theme.css?tckkx1	5.6 KiB	84 ms
/sites/default/themes/custom/cernbase/css/components/acco...	860 B
home.cern/sites/default/themes/custom/cernbase/css/cookies.css?tckkx1	1008 B
/sites/default/themes/custom/cernbase/css/components/soci...	946 B
/sites/default/themes/custom/cernbase/css/components/prog...	1.0 KiB
/sites/default/themes/custom/cernbase/css/components/drop...	1.6 KiB
home.cern/sites/default/themes/custom/cernbase/css/components/header.css?tckkx1	3.2 KiB
home.cern/sites/default/themes/custom/cernbase/css/components/forms.css?tckkx1	2.3 KiB
home.cern/sites/default/themes/custom/cernbase/css/components/fields.css?tckkx1	970 B
/sites/default/themes/custom/cernbase/css/components/pagi...	1.3 KiB
home.cern/sites/default/themes/custom/cernbase/css/components/footer.css?tckkx1	1.8 KiB
home.cern/sites/default/themes/custom/cernbase/css/base.css?tckkx1	23.1 KiB	164 ms
home.cern/sites/default/files/color/cernpublic-ac827e9a/colors.css?tckkx1	5.8 KiB	84 ms
home.cern/modules/contrib/paragraphs/css/paragraphs.unpublished.css?tckkx1	314 B
home.cern/sites/default/themes/custom/cernbase/css/layout.css?tckkx1	3.0 KiB
home.cern/core/modules/layout_discovery/layouts/onecol/onecol.css?tckkx1	374 B
home.cern/core/modules/views/css/views.module.css?tckkx1	692 B
/modules/custom/cern-components/patterns/molecules/menu/c...	5.0 KiB	84 ms
/modules/custom/cern-components/patterns/molecules/row/cs...	2.3 KiB
/modules/custom/cern-components/patterns/molecules/margin...	438 B
/modules/custom/cern-components/patterns/molecules/previe...	2.8 KiB
/modules/custom/cern-components/patterns/molecules/header...	1.1 KiB
/modules/custom/cern-components/patterns/molecules/header...	2.9 KiB
/modules/custom/cern-components/patterns/atoms/background...	844 B
/modules/custom/cern-components/patterns/molecules/agenda...	2.6 KiB
home.cern/modules/custom/cern-toolbar/assets/css/cookieconsent.css?tckkx1	781 B
home.cern/modules/custom/cern-toolbar/assets/css/screen.css?tckkx1	2.0 KiB
home.cern/core/modules/system/css/components/tablesort.module.css?tckkx1	623 B
/core/modules/system/css/components/system-status-report-...	513 B
framework.web.cern.ch/framework/3.0/js/colorbox/colorbox.css	1.5 KiB	211 ms
framework.web.cern.ch/framework/3.0/js/prism/prism.css	2.3 KiB	211 ms
framework.web.cern.ch/framework/3.0/js/owlcarousel/css/owl.theme.default.css	949 B	211 ms
framework.web.cern.ch/framework/3.0/js/owlcarousel/css/owl.carousel.css	1.5 KiB	211 ms
/core/modules/system/css/components/system-status-report-...	815 B
home.cern/core/modules/system/css/components/reset-appearance.module.css?tckkx1	507 B
home.cern/core/modules/system/css/components/system-status-counter.css?tckkx1	1023 B
/core/modules/system/css/components/position-container.mo...	352 B
home.cern/core/modules/system/css/components/resize.module.css?tckkx1	528 B
home.cern/core/modules/system/css/components/nowrap.module.css?tckkx1	353 B
home.cern/core/modules/system/css/components/js.module.css?tckkx1	920 B
home.cern/core/modules/system/css/components/item-list.module.css?tckkx1	545 B
home.cern/core/modules/system/css/components/hidden.module.css?tckkx1	955 B
home.cern/core/modules/system/css/components/details.module.css?tckkx1	385 B
home.cern/core/modules/system/css/components/container-inline.module.css?tckkx1	533 B	124 ms
home.cern/core/modules/system/css/components/clearfix.module.css?tckkx1	565 B	124 ms
home.cern/core/modules/system/css/components/align.module.css?tckkx1	742 B	124 ms
home.cern/core/modules/system/css/components/fieldgroup.module.css?tckkx1	352 B	124 ms
home.cern/core/misc/components/progress.module.css?tckkx1	1.1 KiB	124 ms
home.cern/modules/custom/cern-loading/css/cern_loading.css?tckkx1	453 B

These insights are also available in the Chrome DevTools Performance Panel - record a trace to view more detailed information.

Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric.

Why this matters

Performance issues directly impact user engagement and conversion rates.

TTI

These are the largest layout shifts observed on the page. Each table item represents a single layout shift, and shows the element that shifted the most. Below each item are possible root causes that led to the layout shift. Some of these layout shifts may not be included in the CLS metric value due to windowing. Learn how to improve CLS

Why this matters

Performance issues directly impact user engagement and conversion rates.

Element	Layout shift score
body.page-node-193099 `body.page-node-193099`	0.543
div.layout > div.layout__region > div.field > div.field--item `div.layout > div.layout__region > div.field > div.field--item`	0.002
div.layout > div.layout__region > div.field > div.field--item `div.layout > div.layout__region > div.field > div.field--item`	0.001
div.layout > div.layout__region > div.field > div.field--item `div.layout > div.layout__region > div.field > div.field--item`	0.000
div.layout > div.layout__region > div.field > div.field--item `div.layout > div.layout__region > div.field > div.field--item`	0.000
div.layout > div.layout__region > div.field > div.field--item `div.layout > div.layout__region > div.field > div.field--item`	0.000
div.layout > div.layout__region > div.field > div.field--item `div.layout > div.layout__region > div.field > div.field--item`	0.000
div.layout > div.layout__region > div.field > div.field--item `div.layout > div.layout__region > div.field > div.field--item`	0.000
div.layout > div.layout__region > div.field > div.field--item `div.layout > div.layout__region > div.field > div.field--item`	0.000
div.layout > div.layout__region > div.field > div.field--item `div.layout > div.layout__region > div.field > div.field--item`	0.000
19 April, 2026 `div.component-preview-cards__box_wrapper > div.component-preview-cards__box > div.preview-cards__subtext > div.preview-card__date`	0.000
div.layout > div.layout__region > div.field > div.field--item `div.layout > div.layout__region > div.field > div.field--item`	0.000
div.layout > div.layout__region > div.field > div.field--item `div.layout > div.layout__region > div.field > div.field--item`	0.000
div.layout > div.layout__region > div.field > div.field--item `div.layout > div.layout__region > div.field > div.field--item`	0.000
div.layout > div.layout__region > div.field > div.field--item `div.layout > div.layout__region > div.field > div.field--item`	0.000

Diagnostics

Minifying CSS files can reduce network payload sizes. Learn how to minify CSS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 4.3 KiB

URL	Transfer Size	Est Savings
home.cern/sites/default/themes/custom/cernbase/css/base.css?tckkx1	23.1 KiB	4.3 KiB

Minifying JavaScript files can reduce payload sizes and script parse time. Learn how to minify JavaScript.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 26.9 KiB

URL	Transfer Size	Est Savings
home.cern/core/misc/ajax.js?v=10.4.5	17.0 KiB	11.9 KiB
framework.web.cern.ch/framework/3.0/js/owlcarousel/js/owl.carousel.js	18.5 KiB	7.2 KiB
home.cern/core/misc/drupal.js?v=10.4.5	6.1 KiB	4.8 KiB
home.cern/themes/contrib/bootstrap/js/drupal.bootstrap.js?tckkx1	4.9 KiB	2.9 KiB

Reduce unused rules from stylesheets and defer CSS not used for above-the-fold content to decrease bytes consumed by network activity. Learn how to reduce unused CSS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 21.6 KiB

URL	Transfer Size	Est Savings
home.cern/sites/default/themes/custom/cernbase/css/base.css?tckkx1	22.8 KiB	21.6 KiB

Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Transfer Size
home.cern/sites/default/files/2026-04/Antimatter-3.png	5.0 MiB
home.cern/sites/default/files/2026-04/g2-experiment_1.png	4.7 MiB
home.cern/sites/default/files/2026-04/Toponium.png	1.3 MiB
home.cern/sites/default/files/2025-12/202310-230_50_2_1.jpg	1.1 MiB
home.cern/sites/default/files/2026-04/55182696113-0c4398702d-o-2_0.jpg	677.0 KiB
framework.web.cern.ch/framework/3.0/images/loader.gif	512.8 KiB
home.cern/modules/custom/cern-loading/images/loader.gif	512.7 KiB
home.cern/sites/default/files/2025-12/69576_1.jpeg	427.0 KiB
home.cern/sites/default/files/2025-12/60100_2.jpeg	300.6 KiB
/sites/default/files/2025-12/Artist Rasheedah Phillips fr...	264.0 KiB

Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL
home `div.site-info > div.site-info__logo > a > img`	home.cern/sites/default/files/logo/cern-logo.png

More information about the performance of your application. These numbers don't directly affect the Performance score.

●Max Potential First Input Delay 100 ms

●Document request latency

●Optimize DOM size

●LCP breakdown

●Optimize viewport for mobile

●Reduce unused JavaScript

●JavaScript execution time 0.2 s

●Minimizes main-thread work 0.9 s

●Avoid long main-thread tasks 1 long task found

●Avoid non-composited animations 7 animated elements found

●Page didn't prevent back/forward cache restoration

●Network Requests

●Network Round Trip Times 30 ms

●Server Backend Latencies 20 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Avoid multiple page redirects

●Initial server response time was short Root document took 70 ms

○INP breakdown

○User Timing marks and measures

Accessibility

ARIA

Each ARIA `role` supports a specific subset of `aria-*` attributes. Mismatching these invalidates the `aria-*` attributes. Learn how to match ARIA attributes to their roles.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
\| EN `div#bs-example-navbar-collapse-1 > ul.nav > li.dropdown > a.dropdown-toggle`

These are opportunities to improve the usage of ARIA in your application which may enhance the experience for users of assistive technology, like a screen reader.

Names and labels

When a button doesn't have an accessible name, screen readers announce it as "button", making it unusable for users who rely on screen readers. Learn how to make buttons more accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.views-element-container > div.events-collision > div.view-content > button.bubbly-button `div.views-element-container > div.events-collision > div.view-content > button.bubbly-button`

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--2 > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--2 > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--3 > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--3 > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--2 > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--2 > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--4 > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--4 > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--5 > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--5 > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--3 > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--3 > a.box-link`
div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--6 > a.box-link `div.carousel-cern-item > div.horizontal-boxes-row > div#preview-card--6 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--8 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--8 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--9 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--9 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--10 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--10 > a.box-link`
div.component-row__row > div.component-row__column > div#preview-card--11 > a.box-link `div.component-row__row > div.component-row__column > div#preview-card--11 > a.box-link`
div.component-row__row > div.component-row__column > div#preview-card--12 > a.box-link `div.component-row__row > div.component-row__column > div#preview-card--12 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--19 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--19 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--20 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--20 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--21 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--21 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--22 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--22 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--23 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--23 > a.box-link`
div.component-row__column > div.box-effects-wrapper > div#preview-card--24 > a.box-link `div.component-row__column > div.box-effects-wrapper > div#preview-card--24 > a.box-link`

These are opportunities to improve the semantics of the controls in your application. This may enhance the experience for users of assistive technology, like a screen reader.

Contrast

Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Copyright `body.page-node-193099 > footer > div.copy-wrapper > a`

These are opportunities to improve the legibility of your content.

Navigation

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
ATLAS sets record limits on Higgs boson’s sel... `div.component-preview-cards__box_wrapper > div.component-preview-cards__box > div.preview-card__title > h3.standard-title`
Plan your CERN visit `div.component-preview-cards__box_wrapper > div.component-preview-cards__box > div.preview-card__title > h3`
Axiverse Lampposts `div.agenda-box-pattern > div.agenda-box-pattern__box-wrapper > div.agenda-box-link > h3`
The Higgs boson `div.component-preview-cards__box_wrapper > div.component-preview-cards__box > div.preview-card__title > h3`

These are opportunities to improve keyboard navigation in your application.

○Interactive controls are keyboard focusable

○Interactive elements indicate their purpose and state

○The page has a logical tab order

○Visual order on the page follows DOM order

○User focus is not accidentally trapped in a region

○The user's focus is directed to new content added to the page

○HTML5 landmark elements are used to improve navigation

○Offscreen content is hidden from assistive technology

○Custom controls have associated labels

○Custom controls have ARIA roles

●`[aria-hidden="true"]` is not present on the document `<body>`

●`[role]`s have all required `[aria-*]` attributes

●`[role]` values are valid

●`[aria-*]` attributes have valid values

●`[aria-*]` attributes are valid and not misspelled

●Image elements have `[alt]` attributes

●`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.

●ARIA attributes are used as specified for the element's role

●`[aria-hidden="true"]` elements do not contain focusable descendents

●Elements use only permitted ARIA attributes

●Document has a `<title>` element

●`<html>` element has a `[lang]` attribute

●`<html>` element has a valid value for its `[lang]` attribute

●Links are distinguishable without relying on color.

●Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).

●List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements

●No element has a `[tabindex]` value greater than 0

●Touch targets have sufficient size and spacing.

●Document has a main landmark.

●Deprecated ARIA roles were not used

●Identical links have the same purpose.

○`[accesskey]` values are unique

○`button`, `link`, and `menuitem` elements have accessible names

○Elements with `role="dialog"` or `role="alertdialog"` have accessible names.

○ARIA input fields have accessible names

○ARIA `meter` elements have accessible names

○ARIA `progressbar` elements have accessible names

○Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.

○`[role]`s are contained by their required parent element

○Elements with the `role=text` attribute do not have focusable descendents.

○ARIA toggle fields have accessible names

○ARIA `tooltip` elements have accessible names

○ARIA `treeitem` elements have accessible names

○The page contains a heading, skip link, or landmark region

○`<dl>`'s contain only properly-ordered `<dt>` and `<dd>` groups, `<script>`, `<template>` or `<div>` elements.

○Definition list items are wrapped in `<dl>` elements

○ARIA IDs are unique

○No form fields have multiple labels

○`<frame>` or `<iframe>` elements have a title

○`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.

○Input buttons have discernible text.

○`<input type="image">` elements have `[alt]` text

○Form elements have associated labels

○The document does not use `<meta http-equiv="refresh">`

○`<object>` elements have alternate text

○Select elements have associated label elements.

○Skip links are focusable.

○Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.

○`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.

○`[lang]` attributes have a valid value

○`<video>` elements contain a `<track>` element with `[kind="captions"]`

○Tables have different content in the summary attribute and `<caption>`.

○All heading elements contain content.

○Uses ARIA roles only on compatible elements

○Image elements do not have `[alt]` attributes that are redundant text.

○Elements with visible text labels have matching accessible names.

○Tables use `<caption>` instead of cells with the `[colspan]` attribute to indicate a caption.

○`<td>` elements in a large `<table>` have one or more table headers.

Best Practices

General

Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more about this errors in console diagnostic audit

Why this matters

Performance issues directly impact user engagement and conversion rates.

Source	Description
home.cern/libraries/MathJax/MathJax.js?config=TeX-AMS-MML_HTMLorMML	`Failed to load resource: the server responded with a status of 404 (Not Found)`
home.cern/	`Refused to apply style from 'https://home.cern/sites/default/themes/custom/cernpublic/css/blocks.css?tckkx1' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled.`
home.cern/	`Refused to execute script from 'https://home.cern/libraries/MathJax/MathJax.js?config=TeX-AMS-MML_HTMLorMML' because its MIME type ('text/html') is not executable, and strict MIME type checking is enabled.`

●Uses HTTPS

●Avoids deprecated APIs

●Avoids third-party cookies

●Allows users to paste into input fields

●Avoids requesting the geolocation permission on page load

●Avoids requesting the notification permission on page load

●Displays images with correct aspect ratio

●Serves images with appropriate resolution

●Page has the HTML doctype

●Properly defines charset

●No issues in the `Issues` panel in Chrome Devtools

●Ensure CSP is effective against XSS attacks

●Use a strong HSTS policy

●Ensure proper origin isolation with COOP

●Mitigate DOM-based XSS with Trusted Types

●Detected JavaScript libraries

●Page has valid source maps

○Redirects HTTP traffic to HTTPS

○Mitigate clickjacking with XFO or CSP

100

SEO

○Structured data is valid

●Page isn’t blocked from indexing

●Document has a `<title>` element

●Document has a meta description

●Page has successful HTTP status code

●Links have descriptive text

●Links are crawlable

●robots.txt is valid

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`

●Document has a valid `rel=canonical`

Results for https://home.cern

Site Health

How you compare

Top Priorities (5)

Fix Priority Matrix

Quick Wins

Strategic

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What fixing these means

Conversion Barriers

Speed (2)

Trust (2)

Content (2)

Navigation (2)

Return on Investment

Investment

Monthly returns

Regulatory risk avoided

Estimated Remediation Cost

Cost by category

Cost by effort level

What Inaction Is Costing You

Compliance Risk

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Lighthouse Scores

Core Web Vitals

Detailed Report

Performance

Insights

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Accessibility

Contrast

Navigation

Names and labels

Best Practices

General

SEO

Lighthouse Scores

Core Web Vitals

Detailed Report

Performance

Insights

Diagnostics

Accessibility

ARIA

Names and labels

Contrast

Navigation

Best Practices

General

SEO

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