Lighthouse Desktop

· 0 checks — Desktop Lighthouse audit -- Performance, Accessibility, Best Practices, and SEO category breakdown.

SCORE

GRADE

FIX

REVIEW

PASS

INFO

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

Performance issues directly impact user engagement and conversion rates.

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.

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Est Savings
fonts.gstatic.com/s/roboto/v48/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2	45 ms
/wp-content/themes/bsdstarter/src/fonts/Fonts/1475724/f4b...	20 ms
/wp-content/themes/bsdstarter/src/fonts/Fonts/5591154/55f...	20 ms
/wp-content/themes/bsdstarter/src/fonts/Fonts/5591097/6ce...	15 ms
fonts.gstatic.com/s/roboto/v48/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff2	15 ms

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

items: [map[reflowTime:0.95 source:map[column:29748 line:2 type:source-location url:https://computerhistory.org/wp-content/themes/bsdstarter/src/js/vendor/jquery.js?ver=3.4.1 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:26.326 source:map[type:text value:[unattributed]]] map[reflowTime:1.02 source:map[column:145132 line:3547 type:source-location url:https://computerhistory.org/wp-content/themes/bsdstarter/assets/js/source.dev.js?ver=0.0.3 urlProvider:network]] map[reflowTime:3.112 source:map[column:52029 line:1 type:source-location url:https://computerhistory.org/wp-content/themes/bsdstarter/src/js/vendor/jquery.js?ver=3.4.1 urlProvider:network]] map[reflowTime:0.326 source:map[column:52087 line:1 type:source-location url:https://computerhistory.org/wp-content/themes/bsdstarter/src/js/vendor/jquery.js?ver=3.4.1 urlProvider:network]] map[reflowTime:0.355 source:map[column:52151 line:1 type:source-location url:https://computerhistory.org/wp-content/themes/bsdstarter/src/js/vendor/jquery.js?ver=3.4.1 urlProvider:network]] map[reflowTime:17.514 source:map[column:51353 line:1 type:source-location url:https://computerhistory.org/wp-content/themes/bsdstarter/src/js/vendor/jquery.js?ver=3.4.1 urlProvider:network]] map[reflowTime:2.171 source:map[column:380 line:580 type:source-location url:https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js urlProvider:network]] map[reflowTime:1.418 source:map[column:47 line:303 type:source-location url:https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js urlProvider:network]] map[reflowTime:0.323 source:map[column:376 line:901 type:source-location url:https://www.googletagmanager.com/gtag/destination?id=AW-1065537524&cx=c&gtm=4e64k0 urlProvider:network]] map[reflowTime:0.167 source:map[column:143 line:70 type:source-location url:https://www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js urlProvider:network]] map[reflowTime:0.435 source:map[column:86058 line:22 type:source-location url:https://js.hs-analytics.net/analytics/1776889800000/22740101.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
background image `section.hero > div.hero-background > picture > img`	/wp-content/uploads/2025/06/2024-10-Chatbot-Exhibit-SIS-1...	229.7 KiB	122.6 KiB
Timelines `div.slider__container > a > div.slider__img > img`	computerhistory.org/wp-content/uploads/2019/07/1401_3-760x0-c-default.jpg	95.8 KiB	73.0 KiB
Source Code `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2019/07/MPQDSC-MacpaintWP-760x0-c-def...	87.2 KiB	64.6 KiB
div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img `div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img`	/wp-content/uploads/2021/11/Ada-Lovelace-310x175-c-defaul...	64.7 KiB	55.9 KiB
Tours `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2019/08/The-Rest-CHM-Software-Wing-01...	78.1 KiB	55.4 KiB
Exhibits `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2019/08/at-the-museum-overview-760x0-...	62.0 KiB	38.3 KiB
div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img `div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img`	/wp-content/uploads/2026/01/chm_fellows26_website_all_924...	40.2 KiB	31.4 KiB
div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img `div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img`	/wp-content/uploads/2026/04/Framebuffer-Figure-5-310x175-...	34.9 KiB	26.1 KiB
Fellow Awards `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2021/02/chm_fellows_website_924x551-7...	39.4 KiB	21.6 KiB
div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img `div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img`	/wp-content/uploads/2026/03/APL50-128-scaled-310x175-c-de...	28.0 KiB	19.2 KiB
div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img `div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img`	/wp-content/uploads/2026/04/2026-05-MyYearWithAI-eventgra...	25.1 KiB	16.3 KiB
div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img `div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img`	/wp-content/uploads/2026/03/2026-04-SteveJobsInExile-even...	24.6 KiB	15.8 KiB
div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img `div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img`	/wp-content/uploads/2026/02/chm_apple50_web_image2_960x54...	19.7 KiB	10.9 KiB
TechFest `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2023/09/chm_live_techfest_09-05-760x0...	20.8 KiB	10.3 KiB
div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img `div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img`	/wp-content/uploads/2022/02/chm_home-hero_1440_rev08-310x...	18.3 KiB	9.5 KiB
div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img `div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img`	/wp-content/uploads/2022/02/CHM-March-2012-016-310x175-c-...	16.4 KiB	7.5 KiB
div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img `div.related-articles__column > a > div.related-articles__img-wrapper > div.related-articles__img`	computerhistory.org/wp-content/uploads/2022/09/Rainforest-310x175-c-default.jpg	14.4 KiB	5.6 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-0-IMG

nodeLabel: background image

path: 1,HTML,1,BODY,4,DIV,0,SECTION,0,DIV,0,PICTURE,1,IMG

selector: section.hero > div.hero-background > picture > img

snippet: <img src="https://computerhistory.org/wp-content/uploads/2025/06/2024-10-Chatbot-Exh…" alt="background image">

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

title: Preconnected origins

value: no origins were preconnected

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

title: Preconnect candidates

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Transfer Size	Duration
cdn.addevent.com/legacy2000/libs/atc/1.6.1/atc.min.js?ver=1	8.4 KiB	230 ms
/wp-content/themes/bsdstarter/src/js/vendor/mediaelement-...	46.7 KiB	60 ms
/wp-content/themes/bsdstarter/src/js/vendor/jquery.js?ver...	35.7 KiB	216 ms
computerhistory.org/wp-content/themes/bsdstarter/style.css?v=2026-04-01	32.5 KiB	371 ms
computerhistory.org/wp-content/plugins/add-to-any/addtoany.min.css?ver=1.16	1.3 KiB	60 ms
computerhistory.org/wp-includes/css/dist/block-editor/style.min.css?ver=6.8.3	22.0 KiB	320 ms
/lt/1.css?apiType=css&c=1c75c36c-a46a-4891-8bfa-e317e4c2d...	672 B	234 ms
/wp-content/plugins/popup-maker/dist/packages/block-libra...	1.9 KiB	60 ms
/wp-content/plugins/contact-form-7/includes/css/styles.cs...	1.8 KiB	60 ms
computerhistory.org/wp-includes/css/dist/block-library/style.min.css?ver=6.8.3	19.9 KiB	268 ms
computerhistory.org/wp-includes/css/dist/components/style.min.css?ver=6.8.3	17.1 KiB	268 ms
cdnjs.cloudflare.com/ajax/libs/magnific-popup.js/1.1.0/magnific-popup.css?ver=1	2.1 KiB	235 ms
computerhistory.org/wp-includes/css/dist/preferences/style.min.css?ver=6.8.3	1.3 KiB	164 ms
/wp-content/themes/bsdstarter/assets/css/mediaelementplay...	3.7 KiB	60 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
connect.facebook.net/en_US/fbevents.js	1200.0 s	96.6 KiB
js.hs-analytics.net/analytics/1776889800000/22740101.js	300.0 s	42.3 KiB
/signals/config/1645398289372783?v=2.9.303&r=stable&domai...	1200.0 s	44.8 KiB
js.hs-banner.com/v2/22740101/banner.js	300.0 s	26.5 KiB
www.redditstatic.com/ads/pixel.js	60.0 s	19.0 KiB
/signals/config/2998277347144829?v=2.9.303&r=stable&domai...	1200.0 s	18.2 KiB
snap.licdn.com/li.lms-analytics/insight.min.js	86400.0 s	18.7 KiB
/beacon.min.js/v8c78df7c7c0f484497ecbca7046644da177152312...	86400.0 s	10.7 KiB
js.hsadspixel.net/pixels.js	600.0 s	3.9 KiB
js.hs-scripts.com/22740101.js	90.0 s	1.0 KiB
static.addtoany.com/menu/page.js	86400.0 s	2.2 KiB
/lt/1.css?apiType=css&c=1c75c36c-a46a-4891-8bfa-e317e4c2d...	1.0 s	672 B
/rp.gif?ts=1776889920723&id=a2_fzw3bgak4b5o&event=PageVis...	0.0 ms	666 B
/collect?v=2&fmt=js&pid=3073724&time=1776889920733&li_ads...	0.0 ms	452 B
www.gstatic.com/recaptcha/api2/logo_48.png	604800.0 s	2.3 KiB
/tr/?id=1645398289372783&ev=PageView&dl=https%3A%2F%2Fcom...	0.0 ms	19 B
/tr/?id=2998277347144829&ev=PageView&dl=https%3A%2F%2Fcom...	0.0 ms	16 B
www.gstatic.com/recaptcha/api2/logo_48.png	604800.0 s	0 B

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

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

TTI

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Diagnostics

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 100 ms 81.5 KiB

URL	Transfer Size	Est Savings
computerhistory.org/wp-content/themes/bsdstarter/style.css?v=2026-04-01	31.7 KiB	24.7 KiB
computerhistory.org/wp-includes/css/dist/block-editor/style.min.css?ver=6.8.3	21.2 KiB	21.2 KiB
computerhistory.org/wp-includes/css/dist/block-library/style.min.css?ver=6.8.3	19.2 KiB	19.2 KiB
computerhistory.org/wp-includes/css/dist/components/style.min.css?ver=6.8.3	16.4 KiB	16.4 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

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 50 ms 980.1 KiB

URL	Transfer Size	Est Savings
www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js	361.8 KiB	244.4 KiB
www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js	361.8 KiB	156.2 KiB
www.googletagmanager.com/gtag/js?id=G-NNWSXJ9HYJ&cx=c&gtm=4e64k0	177.6 KiB	113.8 KiB
www.googletagmanager.com/gtag/js?id=G-B7C1ZW7V2R&cx=c&gtm=4e64k0	173.7 KiB	69.3 KiB
www.googletagmanager.com/gtag/js?id=G-KKQR0RS2FE&cx=c&gtm=4e64k0	174.9 KiB	69.2 KiB
www.googletagmanager.com/gtag/js?id=G-XZEKL3FD6N&cx=c&gtm=4e64k0	173.7 KiB	69.2 KiB
www.googletagmanager.com/gtm.js?id=GTM-MLN7JPS	151.5 KiB	63.3 KiB
/wp-content/themes/bsdstarter/assets/js/source.dev.js?ver...	75.5 KiB	52.3 KiB
www.googletagmanager.com/gtag/destination?id=AW-1065537524&cx=c&gtm=4e64k0	177.6 KiB	51.8 KiB
/wp-content/themes/bsdstarter/src/js/vendor/mediaelement-...	46.0 KiB	37.7 KiB
connect.facebook.net/en_US/fbevents.js	96.5 KiB	32.0 KiB
static.addtoany.com/menu/modules/core.ydpp7jcu.js	25.7 KiB	21.0 KiB

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.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js	629 ms	479 ms	107 ms
Unattributable	353 ms	8.5 ms	0.0 ms
js.hs-analytics.net/analytics/1776889800000/22740101.js	244 ms	149 ms	4.6 ms
computerhistory.org/	214 ms	22 ms	8.2 ms
www.googletagmanager.com/gtag/destination?id=AW-1065537524&cx=c&gtm=4e64k0	197 ms	180 ms	15 ms
www.googletagmanager.com/gtag/js?id=G-XZEKL3FD6N&cx=c&gtm=4e64k0	190 ms	136 ms	14 ms
www.googletagmanager.com/gtag/js?id=G-KKQR0RS2FE&cx=c&gtm=4e64k0	157 ms	136 ms	20 ms
www.googletagmanager.com/gtm.js?id=GTM-MLN7JPS	126 ms	110 ms	13 ms
www.googletagmanager.com/gtag/js?id=G-B7C1ZW7V2R&cx=c&gtm=4e64k0	119 ms	101 ms	17 ms
/signals/config/1645398289372783?v=2.9.303&r=stable&domai...	92 ms	75 ms	16 ms
/wp-content/themes/bsdstarter/assets/js/source.dev.js?ver...	72 ms	42 ms	8.1 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	1.7 s
Other	427 ms
Script Parsing & Compilation	277 ms
Style & Layout	241 ms
Garbage Collection	73 ms
Parse HTML & CSS	36 ms
Rendering	24 ms

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Transfer Size
www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js	362.4 KiB
www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js	361.9 KiB
/wp-content/uploads/2025/06/2024-10-Chatbot-Exhibit-SIS-1...	230.4 KiB
www.googletagmanager.com/gtag/destination?id=AW-1065537524&cx=c&gtm=4e64k0	177.9 KiB
www.googletagmanager.com/gtag/js?id=G-NNWSXJ9HYJ&cx=c&gtm=4e64k0	177.6 KiB
www.googletagmanager.com/gtag/js?id=G-KKQR0RS2FE&cx=c&gtm=4e64k0	175.0 KiB
www.googletagmanager.com/gtag/js?id=G-XZEKL3FD6N&cx=c&gtm=4e64k0	173.7 KiB
www.googletagmanager.com/gtag/js?id=G-B7C1ZW7V2R&cx=c&gtm=4e64k0	173.7 KiB
www.googletagmanager.com/gtm.js?id=GTM-MLN7JPS	151.9 KiB
connect.facebook.net/en_US/fbevents.js	96.6 KiB

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL
Source Code `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2019/07/MPQDSC-MacpaintWP-760x0-c-def...
Source Code `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2019/07/MPQDSC-MacpaintWP-760x0-c-def...
Tours `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2019/08/The-Rest-CHM-Software-Wing-01...
Tours `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2019/08/The-Rest-CHM-Software-Wing-01...
Timelines `div.slider__container > a > div.slider__img > img`	computerhistory.org/wp-content/uploads/2019/07/1401_3-760x0-c-default.jpg
Timelines `div.slider__container > a > div.slider__img > img`	computerhistory.org/wp-content/uploads/2019/07/1401_3-760x0-c-default.jpg
Fellow Awards `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2021/02/chm_fellows_website_924x551-7...
Fellow Awards `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2021/02/chm_fellows_website_924x551-7...
Podcast `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2025/02/DedingTech-web-Hero-Image-01-...
Collections `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2019/08/cyc-065-crop-1-760x0-c-defaul...
Podcast `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2025/02/DedingTech-web-Hero-Image-01-...
Collections `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2019/08/cyc-065-crop-1-760x0-c-defaul...
Podcast `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2025/02/DedingTech-web-Hero-Image-01-...
TechFest `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2023/09/chm_live_techfest_09-05-760x0...
TechFest `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2023/09/chm_live_techfest_09-05-760x0...
TechFest `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2023/09/chm_live_techfest_09-05-760x0...
Exhibits `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2019/08/at-the-museum-overview-760x0-...
Exhibits `div.slider__container > a > div.slider__img > img`	/wp-content/uploads/2019/08/at-the-museum-overview-760x0-...
body.home > div.chm-panel-donate > img.chm-img-right `body.home > div.chm-panel-donate > img.chm-img-right`	/wp-content/themes/bsdstarter/assets/img/panel-chm-logo-s...
Computer History Museum Logo `div.container > div.footer-content-3 > a.logo > img`	computerhistory.org/wp-content/themes/bsdstarter/assets/img/chm-logo-short.svg
Computer History Museum Logo `div.nav-section-top > div.logo > a.logo > img.home-logo`	computerhistory.org/wp-content/themes/bsdstarter/assets/img/chm-logo-invert.svg

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

●Layout shift culprits

●Document request latency

●Optimize DOM size

●LCP breakdown

●Modern HTTP

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●User Timing marks and measures 24 user timings

●Avoid long main-thread tasks 9 long tasks found

●Avoid non-composited animations 54 animated elements found

●Page didn't prevent back/forward cache restoration

●Network Requests

●Network Round Trip Times 150 ms

●Server Backend Latencies 150 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Avoid multiple page redirects

●Initial server response time was short Root document took 20 ms

●Avoid large layout shifts 1 layout shift found

○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.

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
div.related-articles__column > a > div.related-articles__content > h5 `div.related-articles__column > a > div.related-articles__content > h5`
Visit `div.slider__container > div.slider__content > a > h5`
div.related-articles__column > a > div.related-articles__content > h5 `div.related-articles__column > a > div.related-articles__content > h5`
CHM BLOG `div.related-articles__column > a > div.related-articles__content > h5`
Game for Grades 3–8 `div.related-articles__column > a > div.related-articles__content > h5`
div.related-articles__column > a > div.related-articles__content > h5 `div.related-articles__column > a > div.related-articles__content > h5`

These are opportunities to improve keyboard navigation in your application.

Names and labels

Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. Learn more about the `alt` attribute.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
body.home > div.chm-panel-donate > img.chm-img-left `body.home > div.chm-panel-donate > img.chm-img-left`
body.home > div.chm-panel-donate > img.chm-img-right `body.home > div.chm-panel-donate > img.chm-img-right`

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.

Best practices

One main landmark helps screen reader users navigate a web page. Learn more about landmarks.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
html.no-js `html.no-js`

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

●Buttons have an accessible name

●`[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

●Background and foreground colors have a sufficient contrast ratio

●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.

●All heading elements contain content.

●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>`.

○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
AttributionReporting	snap.licdn.com/li.lms-analytics/insight.min.js

●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

●Page has valid source maps

○Redirects HTTP traffic to HTTPS

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.

Content Best Practices

Meta descriptions may be included in search results to concisely summarize page content. Learn more about the meta description.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Descriptive link text helps search engines understand your content. Learn how to make links more accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Link destination	Link Text
computerhistory.org/apple-at-50/	Learn more

Informative elements should aim for short, descriptive alternate text. Decorative elements can be ignored with an empty alt attribute. Learn more about the `alt` attribute.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
body.home > div.chm-panel-donate > img.chm-img-left `body.home > div.chm-panel-donate > img.chm-img-left`
body.home > div.chm-panel-donate > img.chm-img-right `body.home > div.chm-panel-donate > img.chm-img-right`

Format your HTML in a way that enables crawlers to better understand your app’s content.

○Structured data is valid

●Page isn’t blocked from indexing

●Document has a `<title>` element

●Page has successful HTTP status code

●Links are crawlable

●robots.txt is valid

●Document has a valid `hreflang`

●Document has a valid `rel=canonical`