C — https://nrc.nl | 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.

Good server performance with room for optimization.

Mostly compliant — a few items need attention.

Rich content metadata — your pages look great everywhere.

Reasonable footprint with room for optimization.

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

Apple · 1113 peers

You 73

Avg 73

At average

0 50 100

Better than 45% of Apple sites See full Apple benchmark →

Cloudflare · 1690 peers

You 73

Avg 74

At average

0 50 100

Better than 37% of Cloudflare sites See full Cloudflare benchmark →

Top Priorities (5)

Content-Security-Policy header is missing

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

Security › Security Headers

Cookie 'T6BNumSun3XSVFoIsgO6+3CPTrcT5olFZNzKv9LY5guLQhjSQejQ+BmClS0_' is missing the Secure flag

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

Security › Cookie Security

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

2 button(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 →

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Markdown

[![BeaverCheck](https://beavercheck.com/badge?url=https%3A%2F%2Fnrc.nl)](https://beavercheck.com/results/f2c5ca18-4095-4c19-a533-d7c12c0db03d)

HTML

<a href="https://beavercheck.com/results/f2c5ca18-4095-4c19-a533-d7c12c0db03d"><img src="https://beavercheck.com/badge?url=https%3A%2F%2Fnrc.nl" alt="BeaverCheck Score"></a>

Image URL

https://beavercheck.com/badge?url=https%3A%2F%2Fnrc.nl

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. 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.

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

1 accessibility issue excludes users who rely on assistive technology.

Conversion Barriers

2 critical 4 warning

6 barrier(s) likely increasing bounce by ~27%.

Speed (2)

Page takes 4.8s to load

+12% bounce

Users abandon at ~3s — you're 2.3s over the 2.5s threshold

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

Page feels frozen for 2.1s

+5% bounce

Clicks on the primary CTA are ignored while JavaScript runs

Fix: Break up long tasks; defer non-critical JavaScript to post-hydration

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

Usability (1)

Layout shifts during page load

+3% bounce

Content movement causes mis-clicks on CTAs and form fields

Fix: Add width/height to images; reserve space for late-loading embeds

Navigation (1)

No skip-to-content link

+1% bounce

Keyboard and screen-reader users must tab through the entire header on every page

Fix: Add a visible-on-focus <a href="#main">Skip to content</a> as the first focusable element

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

Return on Investment

€298 investment → €2,973/month returns + EUR 120,500,000 risk avoided

Payback period: < 1 month First-year ROI: +11892%

Investment

€298

4h · 5 findings

Monthly returns

€2,973 /mo

~€35,676 / year

Conversions recovered €2,973
Bandwidth savings €0.49

Regulatory risk avoided

EUR 120,500,000

if kept compliant

ePrivacy Directive EUR 100,000,000
AVG EUR 20,000,000
EAA EUR 500,000

Payback period

0 12mo 24mo

€170 — 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

€298

3.5 developer hours at €85/hr

Based on Netherlands rates (€85/hr)

Quick wins

€170 4 fixes in ~120 minutes

Start here for the best return on investment

Cost by category

Cost by effort level

Adjust assumptions

Custom rate

€ /hr

Rates reflect fully-loaded developer cost including overhead

How developer rates are sourced

What Inaction Is Costing You

€10,041,667 / month at risk

~€120,500,006 / year if left unfixed

Compliance Risk

€120,500,000

ePrivacy DirectiveAVGEAA

No privacy policy link detected
AVG: EUR 10,000 – EUR 20,000,000
Trackers detected but no cookie policy found
AVG: EUR 5,000 – EUR 10,000,000
Trackers detected but no cookie policy found
AVG: EUR 10,000 – EUR 20,000,000

+110 more

Bandwidth Waste

€0.49 /mo

6622.7 MB/mo × 0.074 EUR/GB

Optimize transfer: save ~662 KB per page load
Saves €0.49/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.

4.20 s

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

4.83 s

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

2.12 s

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

0.241

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

7.02 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.

20.55 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.

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:0.000371] map[node:map[boundingRect:map[bottom:215 height:40 left:0 right:412 top:175 width:412] lhId:page-13-UL nodeLabel:Binnenland Buitenland Economie Den Haag Cultuur Wetenschap Opinie Boeken Leven … path:1,HTML,1,BODY,5,HEADER,5,DIV,0,DIV,0,DIV,0,DIV,0,UL selector:div.header__sections-and-selections__inner > div.header__sections-bar > div.header__sections-bar__inner > ul snippet:<ul> type:node] score:0.000371 subItems:map[items:[map[cause:Web font extra:map[type:url value:https://assets.nrc.nl/static/front/fonts/LFT_Etica_Reg.4bfcdd546.woff2]] map[cause:Web font extra:map[type:url value:https://assets.nrc.nl/static/front/fonts/LFT_Etica_Semibold.1be95c177.woff2]] map[cause:Web font extra:map[type:url value:https://assets.nrc.nl/static/front/fonts/GuardianTextEgyp-Regular-Web.0561af52a.woff2]]] type:subitems]]]

items: [map[node:map[type:text value:Total] score:0.240754] map[node:map[boundingRect:map[bottom:5358 height:5142 left:0 right:412 top:216 width:412] lhId:page-18-DIV nodeLabel:ENERGIEMAATREGELEN Kabinet dealt een beetje met links én een beetje met rechts … path:1,HTML,1,BODY,8,MAIN,2,DIV,0,DIV selector:body.indexpage > main#main-content > div.index-grid > div.block snippet:<div class="block block--has-sidebar block--upper-bigger" data-block-css-class=""> type:node] score:0.174647] map[node:map[boundingRect:map[bottom:5358 height:5142 left:0 right:412 top:216 width:412] lhId:page-18-DIV nodeLabel:ENERGIEMAATREGELEN Kabinet dealt een beetje met links én een beetje met rechts … path:1,HTML,1,BODY,8,MAIN,2,DIV,0,DIV selector:body.indexpage > main#main-content > div.index-grid > div.block snippet:<div class="block block--has-sidebar block--upper-bigger" data-block-css-class=""> type:node] score:0.066107]]

Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response, and enabling text compression.

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

items: [map[reflowTime:20.669 source:map[column:586780 line:1 type:source-location url:https://assets.nrc.nl/static/front/js/main.db164c9ed.js 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:11.953 source:map[type:text value:[unattributed]]] map[reflowTime:9.299 source:map[column:588440 line:0 type:source-location url:https://assets.nrc.nl/static/front/js/main.db164c9ed.js urlProvider:network]] map[reflowTime:20.669 source:map[column:198914 line:0 type:source-location url:https://assets.nrc.nl/static/front/js/main.db164c9ed.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.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/AfS6lyyb8WI6tkDjcBBeqtFjyJg=/1280x768/smart/filters:no_u...	138.1 KiB	99.3 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/zjIylzTEyxWT1jdLeRSTsxctPwE=/1280x768/smart/filters:no_u...	120.5 KiB	86.6 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/JYR7T-jnQlr65I-6NHKpTINLjAI=/1280x768/smart/filters:no_u...	80.6 KiB	57.9 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/6D86HE0N5nzUDFqR648U0Z6zxpY=/1280x768/smart/filters:no_u...	69.6 KiB	50.0 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/JhJvPwx9usJds4f1sehAiRh0-pI=/320x192/smart/filters:no_up...	26.4 KiB	22.9 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/kka50zzkHgok1bWei3kmW6e6l4g=/320x192/smart/filters:no_up...	21.7 KiB	17.3 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/2lrjdxXN1TefMYHYnN6zAultqQw=/320x192/smart/filters:no_up...	20.9 KiB	10.9 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/l5i-rNuZAXiyl6S61SmNQXGeuZ0=/320x192/smart/filters:no_up...	19.1 KiB	9.1 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/rZ-xk9d_DWn1iykVLLDdvfSrrGA=/320x192/smart/filters:no_up...	18.0 KiB	8.0 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/odvGQPZlt_4hBDt_vHBKUTVMcOM=/320x192/smart/filters:no_up...	16.6 KiB	6.6 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/gokpmAgJ0uAI4fhmi93xtqlCFKw=/320x192/smart/filters:no_up...	16.2 KiB	6.2 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/iETBhWYKagm1QO6FpC_YpxG6Pkk=/0x2:1920x1154/320x192/smart...	16.2 KiB	6.2 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/HdIbc_PVxcZ8PY9ktHhkEUgrTgY=/0x45:5994x3641/320x192/smar...	14.2 KiB	4.2 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-3-IMG

nodeLabel: div.nmt-item__image-wrapper > figure.responsive-figure > picture > img

path: 1,HTML,1,BODY,8,MAIN,2,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,SECTION,1,DIV,0,DIV,0,DIV,0,DIV,0,A,0,DIV,0,FIGURE,0,PICTURE,0,IMG

selector: div.nmt-item__image-wrapper > figure.responsive-figure > picture > img

snippet: <img alt="" srcset=" https://images.nrc.nl/8XyoJK90LW_L9qeALR92gektZqQ=/160x96/smart/filters:…" src="https://images.nrc.nl/6D86HE0N5nzUDFqR648U0Z6zxpY=/1280x768/smart/filters:…" decoding="async" sizes=" (min-width: 1408px) calc(.5 * 988px), (min-width: 980px) …" width="160" height="96" class="" pinger-seen="true">

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

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

value: No additional origins are good candidates for preconnecting

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
assets.nrc.nl/static/front/css/split/index.d7cde8467.css	8.9 KiB
assets.nrc.nl/static/front/css/main.11aa071ef.css	13.2 KiB	1.1 s
assets.nrc.nl/static/front/css/split/timed-articles.140afb3fc.css	764 B
assets.nrc.nl/static/front/css/split/layout-home.0f6721656.css	416 B
assets.nrc.nl/static/front/css/split/vorm-variables.fa674b062.css	1.6 KiB
assets.nrc.nl/static/front/css/split/header-and-footer.5e49114f3.css	5.4 KiB	150 ms

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
prod-nrcm.mhtr.be/public/tr/tracker.min.js	14400.0 s	159.2 KiB
cdn.sophi.io/assets/demeter/1/stable/3569875221.js?isConsented=true	900.0 s	40.9 KiB
/11ef8ac9-6270-4d5e-8b99-8d6a5bd60059/loader.js?target_ty...	7200.0 s	30.8 KiB
content3.nrc.nl/script/ootag.v2.min.js	0.0 ms	18.8 KiB
static.chartbeat.com/js/chartbeat.js	7200.0 s	16.1 KiB
cdn.optoutadvertising.com/script/sf/hostOptOut.min.js	0.0 ms	9.6 KiB
static.hotjar.com/c/hotjar-298877.js?sv=7	60.0 s	9.2 KiB
static.chartbeat.com/js/chartbeat_mab.js	7200.0 s	10.1 KiB
cdn.optoutadvertising.com/script/sf/base.min.js	0.0 ms	6.0 KiB
bgmin.cdn.billygrace.com/?t=1776902400000&v=0.1.0.1	0.0 ms	5.7 KiB
/b2?c1=2&c2=11546962&ns_site=total&cs_fpid=1776892005080_...	0.0 ms	303 B
sb.scorecardresearch.com/internal-c2/default/cs.js	86400.0 s	357 B

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

Redirects introduce additional delays before the page can be loaded. Learn how to avoid page redirects.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 1.3 s

URL	Time Spent
nrc.nl/	1.3 s
www.nrc.nl/	0.0 ms

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
ENERGIEMAATREGELEN Kabinet dealt een beetje met links én een beetje met rechts … `body.indexpage > main#main-content > div.index-grid > div.block`	0.175
ENERGIEMAATREGELEN Kabinet dealt een beetje met links én een beetje met rechts … `body.indexpage > main#main-content > div.index-grid > div.block`	0.066
Binnenland Buitenland Economie Den Haag Cultuur Wetenschap Opinie Boeken Leven … `div.header__sections-and-selections__inner > div.header__sections-bar > div.header__sections-bar__inner > ul`	0.000

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

Consider reducing the time spent parsing, compiling, and executing JS. You may find delivering smaller JS payloads helps with this. Learn how to reduce Javascript execution time.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Total CPU Time	Script Evaluation	Script Parse
www.nrc.nl/	3.8 s	83 ms	6.7 ms
load.sst.nrc.nl/kxlupzzx.js?st=KKRPPB	1.5 s	1.4 s	98 ms
assets.nrc.nl/static/front/js/main.db164c9ed.js	846 ms	484 ms	86 ms
Unattributable	725 ms	23 ms	0.0 ms
load.sst.nrc.nl/gtag/js?id=G-Q3L8E2PF4V&cx=c&gtm=4e64k0	518 ms	406 ms	69 ms
prod-nrcm.mhtr.be/public/tr/tracker.min.js	311 ms	180 ms	96 ms
/sdk/22ecd6bfac93de604efec0b75b2c796ee1675f92/modern/sdk....	255 ms	200 ms	54 ms
cdn.sophi.io/assets/demeter/1/stable/3569875221.js?isConsented=true	230 ms	209 ms	21 ms
assets.nrc.nl/static/front/components/js/dmt-icon.2405b9fc1.js	198 ms	125 ms	53 ms
script.hotjar.com/modules.6a0f3932cb1341a35c18.js	174 ms	143 ms	30 ms
assets.nrc.nl/static/front/js/vendor.0677b1b4d.js	171 ms	105 ms	23 ms
static.chartbeat.com/js/chartbeat.js	100 ms	90 ms	5.7 ms
cdn.parsely.com/keys/nrc.nl/p.js	96 ms	81 ms	8.1 ms
static.chartbeat.com/js/chartbeat_mab.js	92 ms	80 ms	3.6 ms

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
Script Evaluation	3.7 s
Other	2.6 s
Style & Layout	1.5 s
Rendering	660 ms
Script Parsing & Compilation	602 ms
Parse HTML & CSS	175 ms
Garbage Collection	80 ms

Many navigations are performed by going back to a previous page, or forwards again. The back/forward cache (bfcache) can speed up these return navigations. Learn more about the bfcache

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failure reason	Failure type
The page has an unload handler in the main frame.	Actionable
The page has an unload handler in a sub frame.	Actionable
An iframe on the page started a navigation that did not complete.	Not actionable

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 21.2 KiB

URL	Transfer Size	Est Savings
assets.nrc.nl/static/front/css/split/paywall.6b081e5b3.css	11.1 KiB	10.8 KiB
assets.nrc.nl/static/front/css/main.11aa071ef.css	13.0 KiB	10.4 KiB

Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.

Why this matters

Multi-megabyte JavaScript bundles delay every interactive feature on the page.

Learn more ▾

This is the Lighthouse audit fired when too much JS is shipped relative to what executes. The fix isn't a config flag — it requires bundle analysis (webpack-bundle-analyzer, rollup-plugin-visualizer), splitting routes into chunks, lazy-loading off-screen components, and removing unused dependencies. Fundamentally different from minification: minifying reduces byte count, this reduces what's downloaded at all.

Source: Google web.dev / Lighthouse

Estimated savings: 0.0 ms 483.0 KiB

URL	Transfer Size	Est Savings
prod-nrcm.mhtr.be/public/tr/tracker.min.js	158.7 KiB	113.1 KiB
assets.nrc.nl/static/front/js/main.db164c9ed.js	118.5 KiB	76.5 KiB
/sdk/22ecd6bfac93de604efec0b75b2c796ee1675f92/modern/sdk....	100.5 KiB	63.4 KiB
assets.nrc.nl/static/front/components/js/dmt-icon.2405b9fc1.js	89.4 KiB	63.1 KiB
load.sst.nrc.nl/gtag/js?id=G-Q3L8E2PF4V&cx=c&gtm=4e64k0	161.4 KiB	61.3 KiB
load.sst.nrc.nl/kxlupzzx.js?st=KKRPPB	166.0 KiB	45.2 KiB
script.hotjar.com/modules.6a0f3932cb1341a35c18.js	56.1 KiB	35.8 KiB
assets.nrc.nl/static/front/js/vendor.0677b1b4d.js	49.3 KiB	24.7 KiB

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

●Optimize DOM size

●Font display

●LCP breakdown

●Modern HTTP

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●Avoids enormous network payloads Total size was 2,156 KiB

●User Timing marks and measures 8 user timings

●Avoid long main-thread tasks 20 long tasks found

●Avoid non-composited animations 4 animated elements found

●Image elements have explicit `width` and `height`

●Network Requests

●Network Round Trip Times 250 ms

●Server Backend Latencies 180 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Initial server response time was short Root document took 170 ms

○INP breakdown

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
22 apr 2026 `a.podcast-index__card-item > section > footer > span`
22 apr 2026 `a.podcast-index__card-item > section > footer > span`
Volg `div.block__header__inner-bis > div.follow-topic > button.follow-button > span`
Volg `div.block__header__inner-bis > div.follow-topic > button.follow-button > span`

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
ENERGIEMAATREGELEN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ASIEL `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
BLOG AMERIKAANSE POLITIEK `div#item211367 > div.nmt-item__inner > header.nmt-item__content > h6.nmt-item__flag`
TOBACCO AND VAPES BILL `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
AANSLUITSTOP `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ANALYSE ASIELDEBAT `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
STRAAT VAN HORMUZ `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
RECHTSZAAK `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ALGERIJE `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
SCHIETPARTIJ `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
GEWELD `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
STRAAT VAN HORMUZ `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
OEKRAÏNE `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ANALYSE VEILIGHEID `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
MIDDEN-OOSTEN `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
WET OPEN OVERHEID `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
OORLOG IRAN `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
VOGELGRIEP `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
BLOG AMERIKAANSE POLITIEK `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ANALYSE VEILIGHEID `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
AANSLUITSTOP `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ANALYSE ASIELDEBAT `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
REPORTAGE `div.nmt-item > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
OPINIE CONSUMPTIEMAATSCHAPPIJ `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
TRANS RECHTEN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
CULTUURDAGBOEK `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
RUBRIEK CLOSE-UP `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ANALYSE VEILIGHEID `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ESSAY EFTELING-KUNST `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
RECENSIE BLOEMEN \| ●● `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
INTERVIEW THEATERMAKERS DE HOE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
COLUMN IN HET LAND `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
COLUMN CAROLIEN ROELANTS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
OPINIE SCHOONHEIDSIDEALEN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
JAPKE-D. DENKT MEE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
KWALITEITSJOURNALISTIEK `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
THE ECONOMIST FREE EXCHANGE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
THE ECONOMIST `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
THE ECONOMIST `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
INTERVIEW VERWEESDE ROOFKUNST `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ANALYSE STEMMING ASIELWETTEN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
RECHTSZAAK `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ONTHEEMDING `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
PODCAST `a.podcast-index__card-item > section > header > h6.nmt-item__flag`
Onbehaarde Apen `a.podcast-index__card-item > section > footer > h5`
Vandaag `a.podcast-index__card-item > section > footer > h5`
Cocaïnekoorts `a.podcast-index__card-item > section > footer > h5`
Wereldzaken `a.podcast-index__card-item > section > footer > h5`
Haagse Zaken `a.podcast-index__card-item > section > footer > h5`
Het Uur `a.podcast-index__card-item > section > footer > h5`
Zo simpel is het niet – Stellinga & Schinkel over economie `a.podcast-index__card-item > section > footer > h5`
MUZIEKGIDS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
THEATERGIDS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
STREAMINGGIDS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
BOEKENTIPS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
SCHIETPARTIJ `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
GEWELD `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
REPORTAGE DOCENTENOPLEIDING FRIES `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
WET OPEN OVERHEID `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
NIEUWE PARTIJ `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
COLUMN IN HET LAND `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ENERGIE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ANALYSE OORLOG IN IRAN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
INTERVIEW HONGARIJE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ANALYSE EU EN ISRAËL `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
WAPENVERKOOP `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ECONOMIEBLOG `div#item213021 > div.nmt-item__inner > header.nmt-item__content > h6.nmt-item__flag`
INTERVIEW `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
REPORTAGE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ENERGIECRISIS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
CENSUUR `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.block--focus__flag`
RECENSIE POPFILM \| ●●● `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
INTERVIEW TRULY NAKED `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
PLANTENFILM \| ●●●●● `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
FOTOGRAFIE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.block--focus__flag`
FOTOGRAFIE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
INBEELD ARTEMIS II `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
PILLURALLI `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ANALYSE KNVB-BEKER `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
REPORTAGE AMSTEL GOLD RACE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
VOETBAL `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
INTERVIEW WIELERKLASSIEKER `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
DURF TE VRAGEN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ALLEDAAGSE WETENSCHAP `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
OPHEF `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
COLUMN ELLEN DECKWITZ `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
COLUMN MARJOLEINE DE VOS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
MUSEUMGIDS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
OPGEVOED `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
REACTIES OVERLIJDEN SONJA BAREND `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
TV-RECENSIE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
PUBLIEKE OMROEP `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
TV-RECENSIE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
CONNECTIES `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
KRUISWOORD `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
WOORDEN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
CIJFERS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
OPINIE LEZERSBRIEVEN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
SPITSUUR `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
BERT SCHRIJFT EEN BOEK `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
IKJE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
COLUMN FRITS ABRAHAMS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`

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-*]` attributes match their roles

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

●`[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.

●Links have a discernible name

●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.

●Identical links have the same purpose.

○`[accesskey]` values are unique

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

○Deprecated ARIA roles were not used

○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

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

○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

○`[role]` values are valid

○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

Deprecated APIs will eventually be removed from the browser. Learn more about deprecated APIs.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Deprecation / Warning	Source
Unload event listeners are deprecated and will be removed.	prod-nrcm.mhtr.be/public/tr/tracker.min.js line 14, col 183846
AttributionReporting	/_/service_worker/63b0/sw_iframe.html?origin=https%3A%2F%...

Source maps translate minified code to the original source code. This helps developers debug in production. In addition, Lighthouse is able to provide further insights. Consider deploying source maps to take advantage of these benefits. Learn more about source maps.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Map URL
load.sst.nrc.nl/kxlupzzx.js?st=KKRPPB
assets.nrc.nl/static/front/js/main.db164c9ed.js
prod-nrcm.mhtr.be/public/tr/tracker.min.js	prod-nrcm.mhtr.be/public/tr/tracker.min.js.map

●Uses HTTPS

●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 browser errors logged to the console

●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 clickjacking with XFO or CSP

●Mitigate DOM-based XSS with Trusted Types

●Detected JavaScript libraries

○Redirects HTTP traffic to HTTPS

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.

2.46 s

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

2.46 s

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

176 ms

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

0.881

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

3.06 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.

6.09 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.

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.

items: [map[node:map[type:text value:Total] score:0.880668] map[node:map[boundingRect:map[bottom:13252 height:12955 left:0 right:1350 top:297 width:1350] lhId:page-10-MAIN nodeLabel:NRC - Nieuws, achtergronden en onderzoeksjournalistiek ENERGIEMAATREGELEN Kabin… path:1,HTML,1,BODY,8,MAIN selector:body.indexpage > main#main-content snippet:<main id="main-content" tabindex="-1"> type:node] score:0.815451 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:2172 height:72 left:990 right:1110 top:2100 width:120] lhId:page-22-IMG nodeLabel:a.photo-articles-gtm-click > figure.image > picture.photo-articles-gtm-click > img.photo-articles-gtm-click path:1,HTML,1,BODY,8,MAIN,2,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,1,DIV,3,SECTION,0,DIV,0,DIV,0,SECTION,1,UL,0,LI,0,A,0,FIGURE,0,PICTURE,0,IMG selector:a.photo-articles-gtm-click > figure.image > picture.photo-articles-gtm-click > img.photo-articles-gtm-click snippet:<img alt="" srcset=" https://images.nrc.nl/DZ0lPbQQj_6_s9UV7spFOjdo63o=/0x82:5892x3617/160x96…" src="https://images.nrc.nl/DZ0lPbQQj_6_s9UV7spFOjdo63o=/0x82:5892x3617/160x96/s…" decoding="async" width="160" height="96" class="photo-articles-gtm-click"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:13252 height:12955 left:0 right:1350 top:297 width:1350] lhId:page-10-MAIN nodeLabel:NRC - Nieuws, achtergronden en onderzoeksjournalistiek ENERGIEMAATREGELEN Kabin… path:1,HTML,1,BODY,8,MAIN selector:body.indexpage > main#main-content snippet:<main id="main-content" tabindex="-1"> type:node] score:0.060451 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:2172 height:72 left:990 right:1110 top:2100 width:120] lhId:page-22-IMG nodeLabel:a.photo-articles-gtm-click > figure.image > picture.photo-articles-gtm-click > img.photo-articles-gtm-click path:1,HTML,1,BODY,8,MAIN,2,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,1,DIV,3,SECTION,0,DIV,0,DIV,0,SECTION,1,UL,0,LI,0,A,0,FIGURE,0,PICTURE,0,IMG selector:a.photo-articles-gtm-click > figure.image > picture.photo-articles-gtm-click > img.photo-articles-gtm-click snippet:<img alt="" srcset=" https://images.nrc.nl/DZ0lPbQQj_6_s9UV7spFOjdo63o=/0x82:5892x3617/160x96…" src="https://images.nrc.nl/DZ0lPbQQj_6_s9UV7spFOjdo63o=/0x82:5892x3617/160x96/s…" decoding="async" width="160" height="96" class="photo-articles-gtm-click"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:1973 height:12 left:990 right:1326 top:1961 width:336] lhId:page-9-DIV nodeLabel:div.block__news__inner > div.nmt-layout > div.nmt-layout__sidebar > div.native-ad-item-holder path:1,HTML,1,BODY,8,MAIN,2,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,1,DIV,2,DIV selector:div.block__news__inner > div.nmt-layout > div.nmt-layout__sidebar > div.native-ad-item-holder snippet:<div class="native-ad-item-holder native-ad-item-holder--below-more-news"> type:node] score:0.002365] map[node:map[boundingRect:map[bottom:232 height:61 left:862 right:1326 top:171 width:464] lhId:page-6-DIV nodeLabel:Abonneren Podcasts Digitale krant path:1,HTML,1,BODY,5,HEADER,4,DIV,0,DIV,2,DIV selector:header.header > div.header__main > div.header__inner-container > div.header__buttons snippet:<div class="header__buttons"> type:node] score:0.002115] map[node:map[boundingRect:map[bottom:295 height:62 left:0 right:978 top:233 width:978] lhId:page-1-UL nodeLabel:Binnenland Buitenland Economie Den Haag Cultuur Wetenschap Opinie Boeken Leven … path:1,HTML,1,BODY,5,HEADER,5,DIV,0,DIV,0,DIV,0,DIV,0,UL selector:div.header__sections-and-selections__inner > div.header__sections-bar > div.header__sections-bar__inner > ul snippet:<ul> type:node] score:0.000286 subItems:map[items:[map[cause:Web font extra:map[type:url value:https://assets.nrc.nl/static/front/fonts/GuardianEgyp-Regular-Web.a71963a16.woff2]] map[cause:Web font extra:map[type:url value:https://assets.nrc.nl/static/front/fonts/LFT_Etica_Reg.4bfcdd546.woff2]] map[cause:Web font extra:map[type:url value:https://assets.nrc.nl/static/front/fonts/GuardianTextEgyp-Regular-Web.0561af52a.woff2]] map[cause:Web font extra:map[type:url value:https://assets.nrc.nl/static/front/fonts/LFT_Etica_Book.8f783e38c.woff2]]] type:subitems]]]

items: [map[node:map[type:text value:Total] score:0.12226] map[node:map[boundingRect:map[bottom:950 height:0 left:990 right:1326 top:950 width:336] lhId:page-18-DIV nodeLabel:Laatste nieuws 22:08 ASIEL Opnieuw onrust in Loosdrecht, rechter oordeelt dat a… path:1,HTML,1,BODY,8,MAIN,2,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,1,DIV,1,DIV,0,DIV selector:div.nmt-layout > div.nmt-layout__sidebar > div > div.timed-articles snippet:<div class="timed-articles" data-timed-articles="" data-sticky="false"> type:node] score:0.070018 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:2172 height:72 left:990 right:1110 top:2100 width:120] lhId:page-22-IMG nodeLabel:a.photo-articles-gtm-click > figure.image > picture.photo-articles-gtm-click > img.photo-articles-gtm-click path:1,HTML,1,BODY,8,MAIN,2,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,1,DIV,3,SECTION,0,DIV,0,DIV,0,SECTION,1,UL,0,LI,0,A,0,FIGURE,0,PICTURE,0,IMG selector:a.photo-articles-gtm-click > figure.image > picture.photo-articles-gtm-click > img.photo-articles-gtm-click snippet:<img alt="" srcset=" https://images.nrc.nl/DZ0lPbQQj_6_s9UV7spFOjdo63o=/0x82:5892x3617/160x96…" src="https://images.nrc.nl/DZ0lPbQQj_6_s9UV7spFOjdo63o=/0x82:5892x3617/160x96/s…" decoding="async" width="160" height="96" class="photo-articles-gtm-click"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:13252 height:12955 left:0 right:1350 top:297 width:1350] lhId:page-10-MAIN nodeLabel:NRC - Nieuws, achtergronden en onderzoeksjournalistiek ENERGIEMAATREGELEN Kabin… path:1,HTML,1,BODY,8,MAIN selector:body.indexpage > main#main-content snippet:<main id="main-content" tabindex="-1"> type:node] score:0.049169 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:2172 height:72 left:990 right:1110 top:2100 width:120] lhId:page-22-IMG nodeLabel:a.photo-articles-gtm-click > figure.image > picture.photo-articles-gtm-click > img.photo-articles-gtm-click path:1,HTML,1,BODY,8,MAIN,2,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,1,DIV,3,SECTION,0,DIV,0,DIV,0,SECTION,1,UL,0,LI,0,A,0,FIGURE,0,PICTURE,0,IMG selector:a.photo-articles-gtm-click > figure.image > picture.photo-articles-gtm-click > img.photo-articles-gtm-click snippet:<img alt="" srcset=" https://images.nrc.nl/DZ0lPbQQj_6_s9UV7spFOjdo63o=/0x82:5892x3617/160x96…" src="https://images.nrc.nl/DZ0lPbQQj_6_s9UV7spFOjdo63o=/0x82:5892x3617/160x96/s…" decoding="async" width="160" height="96" class="photo-articles-gtm-click"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:13252 height:12955 left:0 right:1350 top:297 width:1350] lhId:page-10-MAIN nodeLabel:NRC - Nieuws, achtergronden en onderzoeksjournalistiek ENERGIEMAATREGELEN Kabin… path:1,HTML,1,BODY,8,MAIN selector:body.indexpage > main#main-content snippet:<main id="main-content" tabindex="-1"> type:node] score:0.003073 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:2172 height:72 left:990 right:1110 top:2100 width:120] lhId:page-22-IMG nodeLabel:a.photo-articles-gtm-click > figure.image > picture.photo-articles-gtm-click > img.photo-articles-gtm-click path:1,HTML,1,BODY,8,MAIN,2,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,1,DIV,3,SECTION,0,DIV,0,DIV,0,SECTION,1,UL,0,LI,0,A,0,FIGURE,0,PICTURE,0,IMG selector:a.photo-articles-gtm-click > figure.image > picture.photo-articles-gtm-click > img.photo-articles-gtm-click snippet:<img alt="" srcset=" https://images.nrc.nl/DZ0lPbQQj_6_s9UV7spFOjdo63o=/0x82:5892x3617/160x96…" src="https://images.nrc.nl/DZ0lPbQQj_6_s9UV7spFOjdo63o=/0x82:5892x3617/160x96/s…" decoding="async" width="160" height="96" class="photo-articles-gtm-click"> type:node]]] type:subitems]]]

Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response, and enabling text compression.

Why this matters

Performance issues directly impact user engagement and conversion rates.

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:7.336 source:map[column:25900 line:104 type:source-location url:https://assets.nrc.nl/static/front/js/vendor.0677b1b4d.js 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:18.593 source:map[type:text value:[unattributed]]] map[reflowTime:8.996 source:map[column:214017 line:0 type:source-location url:https://assets.nrc.nl/static/front/js/main.db164c9ed.js urlProvider:network]] map[reflowTime:1.671 source:map[column:583759 line:0 type:source-location url:https://assets.nrc.nl/static/front/js/main.db164c9ed.js urlProvider:network]] map[reflowTime:8.292 source:map[column:82845 line:103 type:source-location url:https://assets.nrc.nl/static/front/js/vendor.0677b1b4d.js urlProvider:network]] map[reflowTime:1.95 source:map[column:76610 line:103 type:source-location url:https://assets.nrc.nl/static/front/js/vendor.0677b1b4d.js urlProvider:network]] map[reflowTime:0.328 source:map[column:57 line:24 type:source-location url:https://static.chartbeat.com/js/chartbeat.js urlProvider:network]] map[reflowTime:0.255 source:map[column:123 line:23 type:source-location url:https://static.chartbeat.com/js/chartbeat.js urlProvider:network]] map[reflowTime:15.894 source:map[column:588440 line:0 type:source-location url:https://assets.nrc.nl/static/front/js/main.db164c9ed.js urlProvider:network]] map[reflowTime:0.272 source:map[column:198914 line:0 type:source-location url:https://assets.nrc.nl/static/front/js/main.db164c9ed.js urlProvider:network]]]

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-0-IMG

nodeLabel: div.nmt-item__image-wrapper > figure.responsive-figure > picture > img

path: 1,HTML,1,BODY,8,MAIN,2,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,SECTION,1,DIV,0,DIV,0,DIV,0,DIV,0,A,0,DIV,0,FIGURE,0,PICTURE,0,IMG

selector: div.nmt-item__image-wrapper > figure.responsive-figure > picture > img

snippet: <img alt="" srcset=" https://images.nrc.nl/8XyoJK90LW_L9qeALR92gektZqQ=/160x96/smart/filters:…" src="https://images.nrc.nl/-i4B3fO8tgxuulp_G33CUeLD4q0=/640x384/smart/filters:n…" decoding="async" sizes=" (min-width: 1408px) calc(.5 * 988px), (min-width: 980px) …" width="160" height="96" class="" pinger-seen="true">

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

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

value: No additional origins are good candidates for preconnecting

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
assets.nrc.nl/static/front/css/split/index.d7cde8467.css	8.9 KiB
assets.nrc.nl/static/front/css/main.11aa071ef.css	13.2 KiB	556 ms
assets.nrc.nl/static/front/css/split/timed-articles.140afb3fc.css	764 B
assets.nrc.nl/static/front/css/split/layout-home.0f6721656.css	416 B
assets.nrc.nl/static/front/css/split/vorm-variables.fa674b062.css	1.6 KiB
assets.nrc.nl/static/front/css/split/header-and-footer.5e49114f3.css	5.4 KiB	68 ms

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
prod-nrcm.mhtr.be/public/tr/tracker.min.js	14400.0 s	159.3 KiB
cdn.sophi.io/assets/demeter/1/stable/3569875221.js?isConsented=true	900.0 s	40.9 KiB
cdn.optoutadvertising.com/script/sf/base.js	0.0 ms	24.1 KiB
/11ef8ac9-6270-4d5e-8b99-8d6a5bd60059/loader.js?target_ty...	7200.0 s	31.1 KiB
content3.nrc.nl/script/ootag.v2.min.js	0.0 ms	18.8 KiB
cdn.optoutadvertising.com/script/sf/ext.js	0.0 ms	15.6 KiB
static.chartbeat.com/js/chartbeat.js	7200.0 s	16.1 KiB
/pub/163/prod/display/483321/rehosted_oo/scripts/15/webod...	0.0 ms	10.4 KiB
cdn.optoutadvertising.com/script/sf/hostOptOut.min.js	0.0 ms	9.6 KiB
static.hotjar.com/c/hotjar-298877.js?sv=7	60.0 s	9.2 KiB
static.chartbeat.com/js/chartbeat_mab.js	7200.0 s	10.1 KiB
cdn.optoutadvertising.com/script/sf/base.min.js	0.0 ms	6.0 KiB
bgmin.cdn.billygrace.com/?t=1776902400000&v=0.1.0.1	0.0 ms	5.7 KiB
content3.nrc.nl/script/viewability.js	0.0 ms	4.3 KiB
content3.nrc.nl/script/mraidSideBridge.js	0.0 ms	2.9 KiB
/b2?c1=2&c2=11546962&ns_site=total&cs_fpid=1776892034618_...	0.0 ms	303 B
/pixel?https%3A%2F%2Fadserving.optoutadvertising.com%2Fev...	0.0 ms	184 B
/pixel?https%3A%2F%2Fadserving.optoutadvertising.com%2Fev...	0.0 ms	183 B
/pixel?https://adserving.optoutadvertising.com/viewable?b...	0.0 ms	183 B
sb.scorecardresearch.com/internal-c2/default/cs.js	86400.0 s	359 B
cdn.optoutadvertising.com/script/sf/base.js	0.0 ms	0 B
cdn.optoutadvertising.com/script/sf/ext.js	0.0 ms	0 B
content3.nrc.nl/script/viewability.js	0.0 ms	0 B

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.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/66GEIfdeYiIs4fHvdRqq-NZPFdg=/640x384/smart/filters:no_up...	67.5 KiB	59.1 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/6W5m80s1fbgYfp-ajmLzB4YHmOg=/640x384/smart/filters:no_up...	64.3 KiB	55.9 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/YwsdVI2fav3Hx97cujMnSR9dnug=/640x384/smart/filters:no_up...	63.6 KiB	55.1 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/Ugv_Jb9FZ4KJa2dlIrUJqOpM43g=/640x384/smart/filters:no_up...	50.7 KiB	42.2 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/OCQjHCqH_b038WptE8F2Lv2fRCQ=/640x384/smart/filters:no_up...	50.1 KiB	41.7 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/ycOfe3rDc4fzK-_kS38DOdDwgb4=/640x384/smart/filters:no_up...	54.2 KiB	34.1 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/WvAx1ITuRuUiaxIfLKC0QZWVKzU=/640x384/smart/filters:no_up...	40.6 KiB	32.2 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/c0yHXjen48LOgYWrYh69lkuHSno=/0x2:1920x1154/640x384/smart...	39.9 KiB	31.5 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/m6nDNCh-1M_8wK0PvY3HxuQfuKY=/640x384/smart/filters:no_up...	30.1 KiB	23.8 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/AtOHBnGx2VPQWa22i4RfePiic1U=/640x384/smart/filters:no_up...	43.3 KiB	23.2 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/06EifwYSiT452ri-Kvf-PLYoiRs=/640x384/smart/filters:no_up...	23.2 KiB	18.3 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/-HcOTgovjNwy2jtrYAafToOtH_g=/640x384/smart/filters:no_up...	35.4 KiB	17.7 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/I57VLQZqjq6qWwsD2ZxGgy7r1MM=/0x82:5892x3617/640x384/smar...	20.8 KiB	16.4 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/-i4B3fO8tgxuulp_G33CUeLD4q0=/640x384/smart/filters:no_up...	31.3 KiB	15.6 KiB
div.nmt-item__image-wrapper > figure.responsive-figure > picture > img `div.nmt-item__image-wrapper > figure.responsive-figure > picture > img`	/MLN735lqCETFx-jD0QiWRKgKtO8=/640x384/smart/filters:no_up...	16.6 KiB	13.1 KiB
a.photo-articles-gtm-click > figure.image > picture.photo-articles-gtm-click > img.photo-articles-gtm-click `a.photo-articles-gtm-click > figure.image > picture.photo-articles-gtm-click > img.photo-articles-gtm-click`	/eNtBb2TkBejUDMtm6fqQavGb1Tk=/160x96/smart/filters:no_ups...	8.1 KiB	5.6 KiB
a.photo-articles-gtm-click > figure.image > picture.photo-articles-gtm-click > img.photo-articles-gtm-click `a.photo-articles-gtm-click > figure.image > picture.photo-articles-gtm-click > img.photo-articles-gtm-click`	/3HbiHUOEP-RVOy3T6nwiPZOLt14=/160x96/smart/filters:no_ups...	7.1 KiB	4.6 KiB

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

Redirects introduce additional delays before the page can be loaded. Learn how to avoid page redirects.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 683 ms

URL	Time Spent
nrc.nl/	683 ms
www.nrc.nl/	0.0 ms

Why this matters

Performance issues directly impact user engagement and conversion rates.

Element	Layout shift score
NRC - Nieuws, achtergronden en onderzoeksjournalistiek ENERGIEMAATREGELEN Kabin… `body.indexpage > main#main-content`	0.815
Laatste nieuws 22:08 ASIEL Opnieuw onrust in Loosdrecht, rechter oordeelt dat a… `div.nmt-layout > div.nmt-layout__sidebar > div > div.timed-articles`	0.070
NRC - Nieuws, achtergronden en onderzoeksjournalistiek ENERGIEMAATREGELEN Kabin… `body.indexpage > main#main-content`	0.060
NRC - Nieuws, achtergronden en onderzoeksjournalistiek ENERGIEMAATREGELEN Kabin… `body.indexpage > main#main-content`	0.049
NRC - Nieuws, achtergronden en onderzoeksjournalistiek ENERGIEMAATREGELEN Kabin… `body.indexpage > main#main-content`	0.003
div.block__news__inner > div.nmt-layout > div.nmt-layout__sidebar > div.native-ad-item-holder `div.block__news__inner > div.nmt-layout > div.nmt-layout__sidebar > div.native-ad-item-holder`	0.002
Abonneren Podcasts Digitale krant `header.header > div.header__main > div.header__inner-container > div.header__buttons`	0.002
Binnenland Buitenland Economie Den Haag Cultuur Wetenschap Opinie Boeken Leven … `div.header__sections-and-selections__inner > div.header__sections-bar > div.header__sections-bar__inner > ul`	0.000

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

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
Script Evaluation	1.0 s
Other	673 ms
Style & Layout	406 ms
Rendering	225 ms
Script Parsing & Compilation	196 ms
Parse HTML & CSS	48 ms
Garbage Collection	24 ms

Many navigations are performed by going back to a previous page, or forwards again. The back/forward cache (bfcache) can speed up these return navigations. Learn more about the bfcache

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failure reason	Failure type
The page has an unload handler in the main frame.	Actionable
The page has an unload handler in a sub frame.	Actionable

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 20.9 KiB

URL	Transfer Size	Est Savings
assets.nrc.nl/static/front/css/split/paywall.6b081e5b3.css	11.1 KiB	10.7 KiB
assets.nrc.nl/static/front/css/main.11aa071ef.css	13.0 KiB	10.2 KiB

Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.

Why this matters

Multi-megabyte JavaScript bundles delay every interactive feature on the page.

Learn more ▾

Source: Google web.dev / Lighthouse

Estimated savings: 0.0 ms 619.5 KiB

URL	Transfer Size	Est Savings
prod-nrcm.mhtr.be/public/tr/tracker.min.js	158.8 KiB	113.2 KiB
assets.nrc.nl/static/front/js/main.db164c9ed.js	118.5 KiB	75.7 KiB
/sdk/22ecd6bfac93de604efec0b75b2c796ee1675f92/modern/sdk....	100.5 KiB	63.4 KiB
assets.nrc.nl/static/front/components/js/dmt-icon.2405b9fc1.js	89.4 KiB	63.1 KiB
load.sst.nrc.nl/gtag/js?id=G-Q3L8E2PF4V&cx=c&gtm=4e64k0	161.5 KiB	61.3 KiB
load.sst.nrc.nl/kxlupzzx.js?st=KKRPPB	166.0 KiB	45.2 KiB
script.hotjar.com/survey-v2.8b9993fd273bc1f4ea37.js	60.6 KiB	34.8 KiB
script.hotjar.com/survey-v2.8b9993fd273bc1f4ea37.js	60.6 KiB	34.8 KiB
script.hotjar.com/survey-v2.8b9993fd273bc1f4ea37.js	60.6 KiB	34.8 KiB
script.hotjar.com/survey-v2.8b9993fd273bc1f4ea37.js	60.6 KiB	34.8 KiB
script.hotjar.com/modules.6a0f3932cb1341a35c18.js	56.1 KiB	34.6 KiB
assets.nrc.nl/static/front/js/vendor.0677b1b4d.js	49.3 KiB	23.8 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.


a.podcast-index__card-item > aside > picture > img `a.podcast-index__card-item > aside > picture > img`
a.podcast-index__card-item > aside > picture > img `a.podcast-index__card-item > aside > picture > img`
a.podcast-index__card-item > aside > picture > img `a.podcast-index__card-item > aside > picture > img`
a.podcast-index__card-item > aside > picture > img `a.podcast-index__card-item > aside > picture > img`
a.podcast-index__card-item > aside > picture > img `a.podcast-index__card-item > aside > picture > img`
a.podcast-index__card-item > aside > picture > img `a.podcast-index__card-item > aside > picture > img`
a.podcast-index__card-item > aside > picture > img `a.podcast-index__card-item > aside > picture > img`

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

●Optimize DOM size

●Font display

●LCP breakdown

●Modern HTTP

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●Avoids enormous network payloads Total size was 2,363 KiB

●User Timing marks and measures 8 user timings

●JavaScript execution time 1.1 s

●Avoid long main-thread tasks 8 long tasks found

●Avoid non-composited animations 1 animated element found

●Network Requests

●Network Round Trip Times 250 ms

●Server Backend Latencies 180 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Initial server response time was short Root document took 170 ms

○INP breakdown

Accessibility

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.flexfloat-wrapper > div.flexfloat > div.native-slider__container > button.native-slider__button `div.flexfloat-wrapper > div.flexfloat > div.native-slider__container > button.native-slider__button`
div.flexfloat-wrapper > div.flexfloat > div.native-slider__container > button.native-slider__button `div.flexfloat-wrapper > div.flexfloat > div.native-slider__container > button.native-slider__button`

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
ASIEL `li.timed-articles__item > a > div.timed-articles__title-wrapper > h6.timed-articles__flag`
ALGERIJE `li.timed-articles__item > a > div.timed-articles__title-wrapper > h6.timed-articles__flag`
SCHIETPARTIJ `li.timed-articles__item > a > div.timed-articles__title-wrapper > h6.timed-articles__flag`
RECHTSZAAK `li.timed-articles__item > a > div.timed-articles__title-wrapper > h6.timed-articles__flag`
GEWELD `li.timed-articles__item > a > div.timed-articles__title-wrapper > h6.timed-articles__flag`
ANALYSE ASIELDEBAT `li.timed-articles__item > a > div.timed-articles__title-wrapper > h6.timed-articles__flag`
ANALYSE `a > div.timed-articles__title-wrapper > h6.timed-articles__flag > strong`
STRAAT VAN HORMUZ `li.timed-articles__item > a > div.timed-articles__title-wrapper > h6.timed-articles__flag`
OEKRAÏNE `li.timed-articles__item > a > div.timed-articles__title-wrapper > h6.timed-articles__flag`
22 apr 2026 `a.podcast-index__card-item > section > footer > span`
22 apr 2026 `a.podcast-index__card-item > section > footer > span`
22 apr 2026 `a.podcast-index__card-item > section > footer > span`
Volg `div.block__header__inner-bis > div.follow-topic > button.follow-button > span`
Volg `div.block__header__inner-bis > div.follow-topic > button.follow-button > span`

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
ENERGIEMAATREGELEN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ASIEL `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
BLOG AMERIKAANSE POLITIEK `div#item211367 > div.nmt-item__inner > header.nmt-item__content > h6.nmt-item__flag`
TOBACCO AND VAPES BILL `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
AANSLUITSTOP `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ANALYSE ASIELDEBAT `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
STRAAT VAN HORMUZ `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
RECHTSZAAK `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
OPINIE CONSUMPTIEMAATSCHAPPIJ `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
TRANS RECHTEN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
CULTUURDAGBOEK `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
RUBRIEK CLOSE-UP `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ANALYSE VEILIGHEID `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ESSAY EFTELING-KUNST `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
RECENSIE BLOEMEN \| ●● `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
INTERVIEW THEATERMAKERS DE HOE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ASIEL `li.timed-articles__item > a > div.timed-articles__title-wrapper > h6.timed-articles__flag`
BLOG AMERIKAANSE POLITIEK `li.photo-articles__item > a.photo-articles-gtm-click > div.photo-articles__title-wrapper > h6.photo-articles__flag`
COLUMN IN HET LAND `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
COLUMN CAROLIEN ROELANTS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
OPINIE SCHOONHEIDSIDEALEN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
JAPKE-D. DENKT MEE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
KWALITEITSJOURNALISTIEK `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
THE ECONOMIST FREE EXCHANGE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
THE ECONOMIST `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
THE ECONOMIST `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
INTERVIEW VERWEESDE ROOFKUNST `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ANALYSE STEMMING ASIELWETTEN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
RECHTSZAAK `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ONTHEEMDING `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
PODCAST `a.podcast-index__card-item > section > header > h6.nmt-item__flag`
Onbehaarde Apen `a.podcast-index__card-item > section > footer > h5`
Vandaag `a.podcast-index__card-item > section > footer > h5`
Cocaïnekoorts `a.podcast-index__card-item > section > footer > h5`
Wereldzaken `a.podcast-index__card-item > section > footer > h5`
Haagse Zaken `a.podcast-index__card-item > section > footer > h5`
Het Uur `a.podcast-index__card-item > section > footer > h5`
Zo simpel is het niet – Stellinga & Schinkel over economie `a.podcast-index__card-item > section > footer > h5`
MUZIEKGIDS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
THEATERGIDS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
STREAMINGGIDS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
BOEKENTIPS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
SCHIETPARTIJ `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
GEWELD `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
REPORTAGE DOCENTENOPLEIDING FRIES `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
WET OPEN OVERHEID `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
NIEUWE PARTIJ `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
COLUMN IN HET LAND `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ENERGIE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ANALYSE OORLOG IN IRAN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
INTERVIEW HONGARIJE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ANALYSE EU EN ISRAËL `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
WAPENVERKOOP `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ECONOMIEBLOG `div#item213021 > div.nmt-item__inner > header.nmt-item__content > h6.nmt-item__flag`
INTERVIEW `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
REPORTAGE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ENERGIECRISIS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
CENSUUR `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.block--focus__flag`
FOTOGRAFIE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.block--focus__flag`
ANALYSE KNVB-BEKER `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
REPORTAGE AMSTEL GOLD RACE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
VOETBAL `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
INTERVIEW WIELERKLASSIEKER `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
DURF TE VRAGEN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
ALLEDAAGSE WETENSCHAP `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
OPHEF `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
COLUMN ELLEN DECKWITZ `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
COLUMN MARJOLEINE DE VOS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
MUSEUMGIDS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
OPGEVOED `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
REACTIES OVERLIJDEN SONJA BAREND `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
TV-RECENSIE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
PUBLIEKE OMROEP `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
TV-RECENSIE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
CONNECTIES `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
KRUISWOORD `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
WOORDEN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
CIJFERS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
OPINIE LEZERSBRIEVEN `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
SPITSUUR `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
BERT SCHRIJFT EEN BOEK `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
IKJE `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`
COLUMN FRITS ABRAHAMS `div.nmt-item__inner > a.nmt-item__link > header.nmt-item__content > h6.nmt-item__flag`

These are opportunities to improve keyboard navigation in your application.

Best practices

Touch targets with sufficient size and spacing help users who may have difficulty targeting small controls to activate the targets. Learn more about touch targets.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.nmt-layout__main > section.block--label-cultuur-uitgelicht > header.block__header > a.block__more-link `div.nmt-layout__main > section.block--label-cultuur-uitgelicht > header.block__header > a.block__more-link`
div.nmt-layout__main > section.block--label-opinie-columns > header.block__header > a.block__more-link `div.nmt-layout__main > section.block--label-opinie-columns > header.block__header > a.block__more-link`
div.nmt-layout__main > section.block--label-uit-the-economist > header.block__header > a.block__more-link `div.nmt-layout__main > section.block--label-uit-the-economist > header.block__header > a.block__more-link`
div.nmt-layout__main > section.block--label-beste-van-nrc > header.block__header > a.block__more-link `div.nmt-layout__main > section.block--label-beste-van-nrc > header.block__header > a.block__more-link`
div.nmt-layout__main > section.block--label-nieuwste-afleveringen-nrc-podcasts > header.block__header > a.block__more-link `div.nmt-layout__main > section.block--label-nieuwste-afleveringen-nrc-podcasts > header.block__header > a.block__more-link`
div.nmt-layout__main > section.block--label-uit-thuis > header.block__header > a.block__more-link `div.nmt-layout__main > section.block--label-uit-thuis > header.block__header > a.block__more-link`
div.nmt-layout__main > section.block--label-binnenland > header.block__header > a.block__more-link `div.nmt-layout__main > section.block--label-binnenland > header.block__header > a.block__more-link`
POLITIEK DEN HAAG `div.block__header__inner > div.block__header__inner-bis > h3.block__label > a`
div.nmt-layout__main > section.block--label-politiek-den-haag > header.block__header > a.block__more-link `div.nmt-layout__main > section.block--label-politiek-den-haag > header.block__header > a.block__more-link`
div.nmt-layout__main > section.block--label-buitenland > header.block__header > a.block__more-link `div.nmt-layout__main > section.block--label-buitenland > header.block__header > a.block__more-link`
div.nmt-layout__main > section.block--label-economie > header.block__header > a.block__more-link `div.nmt-layout__main > section.block--label-economie > header.block__header > a.block__more-link`
section.block--focus > div.block--focus__inner > header.block__header > a.block__more-link `section.block--focus > div.block--focus__inner > header.block__header > a.block__more-link`
section.block--focus > div.block--focus__inner > header.block__header > a.block__more-link `section.block--focus > div.block--focus__inner > header.block__header > a.block__more-link`
div.nmt-layout__main > section.block--label-de-puzzels-van-vandaag > header.block__header > a.block__more-link `div.nmt-layout__main > section.block--label-de-puzzels-van-vandaag > header.block__header > a.block__more-link`
CARRIÈRE `div.block__header__inner > div.block__header__inner-bis > h3.block__label > a`
div.nmt-layout__main > section.block--label-carriere > header.block__header > a.block__more-link `div.nmt-layout__main > section.block--label-carriere > header.block__header > a.block__more-link`

These items highlight common accessibility best practices.

○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>`

●`[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 have a discernible name

●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

●Document has a main landmark.

●Identical links have the same purpose.

●Elements with visible text labels have matching accessible names.

○`[accesskey]` values are unique

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

○Deprecated ARIA roles were not used

○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

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

○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

○`[role]` values are valid

○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

○Links are distinguishable without relying on color.

○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.

○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

Deprecated APIs will eventually be removed from the browser. Learn more about deprecated APIs.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Deprecation / Warning	Source
Unload event listeners are deprecated and will be removed.	prod-nrcm.mhtr.be/public/tr/tracker.min.js line 14, col 183846
AttributionReporting	/_/service_worker/63b0/sw_iframe.html?origin=https%3A%2F%...

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Map URL
load.sst.nrc.nl/kxlupzzx.js?st=KKRPPB
assets.nrc.nl/static/front/js/main.db164c9ed.js
prod-nrcm.mhtr.be/public/tr/tracker.min.js	prod-nrcm.mhtr.be/public/tr/tracker.min.js.map

●Uses HTTPS

●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 browser errors logged to the console

●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 clickjacking with XFO or CSP

●Mitigate DOM-based XSS with Trusted Types

●Detected JavaScript libraries

○Redirects HTTP traffic to HTTPS

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://nrc.nl

Site Health

How you compare

Top Priorities (5)

Fix Priority Matrix

Quick Wins

Strategic

Easy Improvements

Deprioritize

What fixing these means

Conversion Barriers

Speed (2)

Trust (2)

Usability (1)

Navigation (1)

Return on Investment

Investment

Monthly returns

Regulatory risk avoided

Payback period

Estimated Remediation Cost

Cost by category

Cost by effort level

What Inaction Is Costing You

Compliance Risk

Bandwidth Waste

Lighthouse Scores

Core Web Vitals

Detailed Report

Performance

Insights

Diagnostics

Accessibility

Contrast

Navigation

Best Practices

General

SEO

Lighthouse Scores

Core Web Vitals

Detailed Report

Performance

Insights

Diagnostics

Accessibility

Names and labels

Contrast

Navigation

Best practices

Best Practices

General

SEO

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