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Lighthouse Mobile

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

Audit breakdown by category with detailed findings.

59

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.

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.

RequestCache TTLTransfer Size
developer.apple.com/assets/elements/icons/sdk-27/sdk-27-256x256_2x.png600.0 s986.7 KiB
developer.apple.com/home/images/tile-tvos-27/tvos-27-large_2x.webp600.0 s271.0 KiB
developer.apple.com/home/images/media-gallery/tile-sept26-event/small_2x.png?1600.0 s247.4 KiB
developer.apple.com/home/images/tile-ipados-27/ipados-27-large_2x.webp600.0 s242.0 KiB
www.apple.com/wss/fonts/SF-Pro-Text/v3/sf-pro-text_semibold.woff2408.0 s230.0 KiB
developer.apple.com/home/images/tile-macos-27/macos-27-large_2x.webp600.0 s213.7 KiB
www.apple.com/wss/fonts/SF-Pro-Text/v3/sf-pro-text_medium.woff23283.0 s230.4 KiB
www.apple.com/wss/fonts/SF-Pro-Text/v3/sf-pro-text_regular.woff23289.0 s216.6 KiB
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...600.0 s170.7 KiB
developer.apple.com/home/images/media-gallery/tile-100sessions/small_2x.jpg600.0 s155.6 KiB
/assets/elements/icons/xcode-s-dark/xcode-s-dark-256x256_...600.0 s155.4 KiB
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...600.0 s142.7 KiB
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...600.0 s135.4 KiB
developer.apple.com/home/images/tile-ios-27/ios-27-large_2x.webp600.0 s130.1 KiB
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...600.0 s119.9 KiB
www.apple.com/wss/fonts/SF-Pro-Display/v3/sf-pro-display_semibold.woff22934.0 s127.7 KiB
www.apple.com/wss/fonts/SF-Pro-Display/v3/sf-pro-display_bold.woff23300.0 s126.2 KiB
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...600.0 s106.5 KiB
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...600.0 s104.3 KiB
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...600.0 s102.4 KiB
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...600.0 s102.3 KiB
www.apple.com/wss/fonts/SF-Pro-Display/v3/sf-pro-display_regular.woff23298.0 s115.5 KiB
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...600.0 s101.3 KiB
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...600.0 s98.8 KiB
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...600.0 s98.6 KiB
developer.apple.com/home/images/tile-visionos-27/visionos-27-large_2x.webp600.0 s97.8 KiB
developer.apple.com/home/images/media-gallery/tile-xcode27beta/small_2x.jpg600.0 s90.9 KiB
developer.apple.com/assets/styles/global.dist.css?19212626191600.0 s83.4 KiB
developer.apple.com/home/images/tile-watchos-27/watchos-27-large_2x.webp600.0 s82.0 KiB
developer.apple.com/home/images/media-gallery/tile-whatsnew/small_2x.jpg600.0 s49.6 KiB
developer.apple.com/home/images/media-gallery/tile-search/small_2x.jpg600.0 s37.9 KiB
developer.apple.com/assets/scripts/lib/jquery/jquery-3.6.0.min.js?35212621148600.0 s31.6 KiB
developer.apple.com/assets/metrics/scripts/analytics.js600.0 s28.4 KiB
developer.apple.com/assets/styles/globalnav.css?34212621148600.0 s14.0 KiB
www.apple.com/wss/fonts/SF-Pro-Icons/v3/sf-pro-icons_regular.woff22254.0 s15.0 KiB
www.apple.com/wss/fonts/SF-Pro-Icons/v3/sf-pro-icons_semibold.woff23290.0 s15.4 KiB
developer.apple.com/assets/styles/dark-mode.css?34212621148600.0 s10.6 KiB
developer.apple.com/assets/includes/global-session-nav/session.js600.0 s8.0 KiB
developer.apple.com/home/scripts/home-alt.js?1600.0 s7.8 KiB
developer.apple.com/home/styles/home-alt.css?581526122041600.0 s6.2 KiB
developer.apple.com/assets/scripts/media-card-infinite.js?2600.0 s5.9 KiB
developer.apple.com/assets/styles/media-card-infinite.css?581526122041600.0 s5.4 KiB
developer.apple.com/assets/styles/footer.dist.css?34212621148600.0 s5.3 KiB
/assets/elements/icons/brandmark/apple-developer-brandmar...600.0 s5.0 KiB
developer.apple.com/assets/scripts/color-scheme-toggle.js600.0 s4.5 KiB
developer.apple.com/assets/scripts/ac-globalnav.built.js?35212621148600.0 s4.3 KiB
developer.apple.com/assets/scripts/suggest-lang.js?50222638203600.0 s3.5 KiB
developer.apple.com/home/styles/personalized.css?581526122041600.0 s3.4 KiB
developer.apple.com/assets/includes/global-session-nav/session.css600.0 s3.4 KiB
developer.apple.com/assets/styles/sc-gallery.css?342126211481600.0 s3.3 KiB
developer.apple.com/assets/metrics/scripts/analytics-module.js?35212621148600.0 s2.8 KiB
developer.apple.com/assets/scripts/language-dropdown.js?56212607203600.0 s2.7 KiB
developer.apple.com/assets/scripts/date-formatter.js600.0 s2.7 KiB
developer.apple.com/assets/elements/icons/symbols/person-3.svg600.0 s2.7 KiB
developer.apple.com/assets/styles/localization.css?34212621148600.0 s2.7 KiB
developer.apple.com/assets/scripts/DeveloperBreadcrumbs.js?35212621148600.0 s2.5 KiB
developer.apple.com/assets/scripts/retinate.js?35212621148600.0 s2.5 KiB
developer.apple.com/assets/scripts/getPersonalizedContent.js600.0 s2.4 KiB
developer.apple.com/assets/scripts/sc-gallery.js?1600.0 s2.4 KiB
developer.apple.com/assets/scripts/global-logout.js?35212621148600.0 s2.2 KiB
developer.apple.com/assets/styles/suggest-lang.css?34212621148600.0 s2.1 KiB
developer.apple.com/assets/scripts/settings.js?35212621148600.0 s2.1 KiB
developer.apple.com/assets/scripts/getUserProfile.js600.0 s2.0 KiB
developer.apple.com/assets/scripts/language-locales.js?50222638203600.0 s1.9 KiB
developer.apple.com/assets/styles/language-dropdown.css?35212621148600.0 s1.9 KiB
www.apple.com/wss/fonts?families=SF+Pro,v3|SF+Pro+Icons,v33278.0 s2.1 KiB
www.apple.com/wss/fonts?family=SF+Mono&v=23546.0 s1.5 KiB
www.apple.com/wss/fonts?family=Apple+Icons&v=12909.0 s1.4 KiB

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.

URLResource SizeEst Savings
a.tile-link > div.tile > div.tile-content > img.center a.tile-link > div.tile > div.tile-content > img.center
developer.apple.com/assets/elements/icons/sdk-27/sdk-27-256x256_2x.png985.4 KiB982.0 KiB
tvOS 27 on Apple TV a.tile-link > div.tile > picture > img.os-image
developer.apple.com/home/images/tile-tvos-27/tvos-27-large_2x.webp269.6 KiB261.6 KiB
iPadOS 27 on iPad a.tile-link > div.tile > picture > img.os-image
developer.apple.com/home/images/tile-ipados-27/ipados-27-large_2x.webp240.7 KiB236.4 KiB
div.card > div.media-block > picture.positioned-media-element > img div.card > div.media-block > picture.positioned-media-element > img
developer.apple.com/home/images/media-gallery/tile-sept26-event/small_2x.png?1246.1 KiB211.9 KiB
macOS 27 on Mac a.tile-link > div.tile > picture > img.os-image
developer.apple.com/home/images/tile-macos-27/macos-27-large_2x.webp212.3 KiB209.0 KiB
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...170.2 KiB161.4 KiB
a.tile-link > div.tile > div.tile-content > img.center a.tile-link > div.tile > div.tile-content > img.center
/assets/elements/icons/xcode-s-dark/xcode-s-dark-256x256_...154.0 KiB147.5 KiB
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...142.2 KiB133.4 KiB
iOS 27 on iPhone a.tile-link > div.tile > picture > img.os-image
developer.apple.com/home/images/tile-ios-27/ios-27-large_2x.webp128.8 KiB121.1 KiB
div.card > div.media-block > picture.positioned-media-element > img div.card > div.media-block > picture.positioned-media-element > img
developer.apple.com/home/images/media-gallery/tile-100sessions/small_2x.jpg154.2 KiB120.0 KiB
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...119.4 KiB110.6 KiB
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...106.0 KiB97.2 KiB
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...100.8 KiB92.0 KiB
visionOS 27 on Apple Vision Pro a.tile-link > div.tile > picture > img.os-image
developer.apple.com/home/images/tile-visionos-27/visionos-27-large_2x.webp96.4 KiB90.4 KiB
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...98.3 KiB89.5 KiB
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...98.1 KiB89.3 KiB
watchOS 27 on Apple Watch a.tile-link > div.tile > picture > img.os-image
developer.apple.com/home/images/tile-watchos-27/watchos-27-large_2x.webp80.6 KiB71.3 KiB
div.card > div.media-block > picture.positioned-media-element > img div.card > div.media-block > picture.positioned-media-element > img
developer.apple.com/home/images/media-gallery/tile-xcode27beta/small_2x.jpg89.6 KiB55.4 KiB
div.card > div.media-block > picture.positioned-media-element > img div.card > div.media-block > picture.positioned-media-element > img
developer.apple.com/home/images/media-gallery/tile-whatsnew/small_2x.jpg48.2 KiB29.5 KiB
div.card > div.media-block > picture.positioned-media-element > img div.card > div.media-block > picture.positioned-media-element > img
developer.apple.com/home/images/media-gallery/tile-search/small_2x.jpg36.6 KiB22.4 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-20-IMG
nodeLabel: div.card > div.media-block > picture.positioned-media-element > img
path: 1,HTML,1,BODY,13,MAIN,1,SECTION,0,DIV,0,DIV,0,DIV,0,UL,4,LI,0,DIV,0,DIV,2,PICTURE,2,IMG
selector: div.card > div.media-block > picture.positioned-media-element > img
snippet: <img src="https://developer.apple.com/home/images/media-gallery/tile-sept26-event/sm…" alt="">

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLProtocol
developer.apple.com/http/1.1
developer.apple.com/assets/styles/global.dist.css?19212626191http/1.1
developer.apple.com/assets/styles/localization.css?34212621148http/1.1
developer.apple.com/assets/scripts/lib/jquery/jquery-3.6.0.min.js?35212621148http/1.1
developer.apple.com/assets/scripts/settings.js?35212621148http/1.1
developer.apple.com/assets/scripts/language-locales.js?50222638203http/1.1
developer.apple.com/assets/scripts/DeveloperBreadcrumbs.js?35212621148http/1.1
developer.apple.com/assets/metrics/scripts/analytics-module.js?35212621148http/1.1
developer.apple.com/assets/scripts/retinate.js?35212621148http/1.1
developer.apple.com/assets/scripts/global-logout.js?35212621148http/1.1
developer.apple.com/assets/includes/global-session-nav/session.csshttp/1.1
developer.apple.com/assets/includes/global-session-nav/session.jshttp/1.1
www.apple.com/wss/fonts?families=SF+Pro,v3|SF+Pro+Icons,v3http/1.1
www.apple.com/wss/fonts?family=SF+Mono&v=2http/1.1
www.apple.com/wss/fonts?family=Apple+Icons&v=1http/1.1
developer.apple.com/home/styles/home-alt.css?581526122041http/1.1
developer.apple.com/home/styles/personalized.css?581526122041http/1.1
developer.apple.com/assets/styles/sc-gallery.css?342126211481http/1.1
developer.apple.com/assets/styles/media-card-infinite.css?581526122041http/1.1
developer.apple.com/assets/scripts/media-card-infinite.js?2http/1.1
developer.apple.com/assets/styles/suggest-lang.css?34212621148http/1.1
developer.apple.com/assets/scripts/suggest-lang.js?50222638203http/1.1
developer.apple.com/assets/styles/globalnav.css?34212621148http/1.1
developer.apple.com/assets/scripts/ac-globalnav.built.js?35212621148http/1.1
developer.apple.com/assets/metrics/scripts/analytics.jshttp/1.1
developer.apple.com/home/images/media-gallery/tile-sept26-event/small_2x.png?1http/1.1
developer.apple.com/home/images/media-gallery/tile-xcode27beta/small_2x.jpghttp/1.1
developer.apple.com/home/images/media-gallery/tile-whatsnew/small_2x.jpghttp/1.1
developer.apple.com/home/images/media-gallery/tile-100sessions/small_2x.jpghttp/1.1
developer.apple.com/home/images/media-gallery/tile-search/small_2x.jpghttp/1.1
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...http/1.1
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...http/1.1
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...http/1.1
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...http/1.1
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...http/1.1
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...http/1.1
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...http/1.1
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...http/1.1
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...http/1.1
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...http/1.1
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...http/1.1
/assets/elements/icons/xcode-s-dark/xcode-s-dark-256x256_...http/1.1
developer.apple.com/home/images/tile-ios-27/ios-27-large_2x.webphttp/1.1
developer.apple.com/home/images/tile-ipados-27/ipados-27-large_2x.webphttp/1.1
developer.apple.com/home/images/tile-macos-27/macos-27-large_2x.webphttp/1.1
developer.apple.com/home/images/tile-tvos-27/tvos-27-large_2x.webphttp/1.1
developer.apple.com/home/images/tile-visionos-27/visionos-27-large_2x.webphttp/1.1
developer.apple.com/home/images/tile-watchos-27/watchos-27-large_2x.webphttp/1.1
developer.apple.com/assets/elements/icons/sdk-27/sdk-27-256x256_2x.pnghttp/1.1
developer.apple.com/assets/elements/icons/symbols/person-3.svghttp/1.1
developer.apple.com/assets/styles/footer.dist.css?34212621148http/1.1
developer.apple.com/assets/scripts/color-scheme-toggle.jshttp/1.1
developer.apple.com/assets/styles/language-dropdown.css?35212621148http/1.1
developer.apple.com/assets/scripts/language-dropdown.js?56212607203http/1.1
developer.apple.com/assets/scripts/sc-gallery.js?1http/1.1
developer.apple.com/home/scripts/home-alt.js?1http/1.1
developer.apple.com/assets/styles/dark-mode.css?34212621148http/1.1
/assets/elements/icons/brandmark/apple-developer-brandmar...http/1.1
www.apple.com/wss/fonts/SF-Pro-Display/v3/sf-pro-display_semibold.woff2http/1.1
www.apple.com/wss/fonts/SF-Pro-Text/v3/sf-pro-text_regular.woff2http/1.1
www.apple.com/wss/fonts/SF-Pro-Text/v3/sf-pro-text_semibold.woff2http/1.1
www.apple.com/wss/fonts/SF-Pro-Display/v3/sf-pro-display_bold.woff2http/1.1
www.apple.com/wss/fonts/SF-Pro-Display/v3/sf-pro-display_regular.woff2http/1.1
developer.apple.com/assets/scripts/getPersonalizedContent.jshttp/1.1
developer.apple.com/assets/scripts/getUserProfile.jshttp/1.1
developer.apple.com/assets/scripts/date-formatter.jshttp/1.1
developer.apple.com/services-session/v1/infohttp/1.1
developer.apple.com/api/v1/content/catalog/http/1.1
developer.apple.com/services-public/event/developer/eventListhttp/1.1
www.apple.com/wss/fonts/SF-Pro-Icons/v3/sf-pro-icons_regular.woff2http/1.1
www.apple.com/wss/fonts/SF-Pro-Icons/v3/sf-pro-icons_semibold.woff2http/1.1
developer.apple.com/favicon.icohttp/1.1
www.apple.com/wss/fonts/SF-Pro-Text/v3/sf-pro-text_medium.woff2http/1.1

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

description: [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints help the browser establish a connection earlier in the page load, saving time when the first request for that origin is made. The following are the origins that the page preconnected to.
title: Preconnected origins
value: no origins were preconnected
description: Add [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints to your most important origins, but try to use no more than 4.
title: Preconnect candidates

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLTransfer SizeDuration
www.apple.com/wss/fonts?families=SF+Pro,v3|SF+Pro+Icons,v32.1 KiB755 ms
www.apple.com/wss/fonts?family=Apple+Icons&v=11.4 KiB755 ms
www.apple.com/wss/fonts?family=SF+Mono&v=21.5 KiB755 ms
developer.apple.com/assets/metrics/scripts/analytics.js28.4 KiB905 ms
developer.apple.com/assets/scripts/ac-globalnav.built.js?352126211484.3 KiB305 ms
developer.apple.com/assets/scripts/global-logout.js?352126211482.2 KiB155 ms
developer.apple.com/assets/scripts/DeveloperBreadcrumbs.js?352126211482.5 KiB155 ms
developer.apple.com/assets/metrics/scripts/analytics-module.js?352126211482.8 KiB155 ms
developer.apple.com/assets/scripts/settings.js?352126211482.1 KiB155 ms
developer.apple.com/assets/scripts/language-locales.js?502226382031.9 KiB155 ms
developer.apple.com/assets/scripts/suggest-lang.js?502226382033.5 KiB305 ms
developer.apple.com/assets/scripts/lib/jquery/jquery-3.6.0.min.js?3521262114831.6 KiB1.5 s
developer.apple.com/assets/styles/global.dist.css?1921262619183.4 KiB2.9 s
developer.apple.com/assets/styles/media-card-infinite.css?5815261220415.4 KiB305 ms
developer.apple.com/assets/styles/globalnav.css?3421262114814.0 KiB755 ms
developer.apple.com/home/styles/home-alt.css?5815261220416.2 KiB755 ms
developer.apple.com/assets/styles/suggest-lang.css?342126211482.1 KiB155 ms
developer.apple.com/assets/styles/sc-gallery.css?3421262114813.3 KiB605 ms
developer.apple.com/assets/includes/global-session-nav/session.css3.4 KiB605 ms
developer.apple.com/assets/styles/localization.css?342126211482.7 KiB455 ms
developer.apple.com/home/styles/personalized.css?5815261220413.4 KiB605 ms

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

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

TTI

Diagnostics

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 11.6 KiB

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 160 ms 89.7 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: 10 ms 21.8 KiB

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 2.2 KiB
URLTransfer SizeEst Savings
developer.apple.com/assets/styles/globalnav.css?3421262114814.0 KiB2.2 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.

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.

CategoryTime Spent
Style & Layout5.4 s
Other4.0 s
Script Evaluation1.4 s
Rendering1.2 s
Garbage Collection148 ms
Parse HTML & CSS106 ms
Script Parsing & Compilation26 ms

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
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...
li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img li.sc-gallery__item > a.sc-gallery__card > div.tile-video > img
/wwdc-services/images/9B2E82C5-4DDF-4B9A-9459-328D8E29769...
tvOS 27 on Apple TV a.tile-link > div.tile > picture > img.os-image
developer.apple.com/home/images/tile-tvos-27/tvos-27-large_2x.webp
macOS 27 on Mac a.tile-link > div.tile > picture > img.os-image
developer.apple.com/home/images/tile-macos-27/macos-27-large_2x.webp
visionOS 27 on Apple Vision Pro a.tile-link > div.tile > picture > img.os-image
developer.apple.com/home/images/tile-visionos-27/visionos-27-large_2x.webp
div.section-content > div.row > div.column > img.filter-w div.section-content > div.row > div.column > img.filter-w
developer.apple.com/assets/elements/icons/symbols/person-3.svg
iPadOS 27 on iPad a.tile-link > div.tile > picture > img.os-image
developer.apple.com/home/images/tile-ipados-27/ipados-27-large_2x.webp

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
●Forced reflow
●LCP breakdown
●Optimize viewport for mobile
●Max Potential First Input Delay 50 ms
●Avoid long main-thread tasks 6 long tasks found
●Avoid non-composited animations 37 animated elements found
●Page didn't prevent back/forward cache restoration
●Network Requests
●Network Round Trip Times 30 ms
●Server Backend Latencies 20 ms
●Tasks
●Diagnostics
●Metrics
●Screenshot Thumbnails
●Final Screenshot
●Script Treemap Data
●Resources Summary
●Avoid multiple page redirects
●Initial server response time was short Root document took 0 ms
●Avoid large layout shifts 1 layout shift found
○INP breakdown
○User Timing marks and measures
79

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.

ARIA

Some ARIA parent roles must contain specific child roles to perform their intended accessibility functions. Learn more about roles and required children elements.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Download now Xcode 27 beta Bring your ideas to life faster using coding agents… div#media-card-gallery > div.media-gallery-wrapper > div.gallery > ul.card-set

ARIA roles must have valid values in order to perform their intended accessibility functions. Learn more about valid ARIA roles.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Download now Xcode 27 beta Bring your ideas to life faster using coding agents… section#priority-router > div#media-card-gallery > div.media-gallery-wrapper > div.gallery

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

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
September 8-9, 2026 · Online appointment ul.sc-gallery__card-set > li.sc-gallery__item > a.sc-gallery__card > p.pc-card__gl-datetime
September 10-11, 2026 · Online appointment ul.sc-gallery__card-set > li.sc-gallery__item > a.sc-gallery__card > p.pc-card__gl-datetime
September 15-16, 2026 · Online appointment ul.sc-gallery__card-set > li.sc-gallery__item > a.sc-gallery__card > p.pc-card__gl-datetime
September 17-18, 2026 · Online appointment ul.sc-gallery__card-set > li.sc-gallery__item > a.sc-gallery__card > p.pc-card__gl-datetime
September 23, 2026 · Online appointment ul.sc-gallery__card-set > li.sc-gallery__item > a.sc-gallery__card > p.pc-card__gl-datetime
October 7, 2026 · Online session ul.sc-gallery__card-set > li.sc-gallery__item > a.sc-gallery__card > p.pc-card__gl-datetime
October 7-8, 2026 · In-person session ul.sc-gallery__card-set > li.sc-gallery__item > a.sc-gallery__card > p.pc-card__gl-datetime
October 7, 2026 · Online appointment ul.sc-gallery__card-set > li.sc-gallery__item > a.sc-gallery__card > p.pc-card__gl-datetime
October 19, 2026 · Online appointment ul.sc-gallery__card-set > li.sc-gallery__item > a.sc-gallery__card > p.pc-card__gl-datetime
October 29, 2026 · Online session ul.sc-gallery__card-set > li.sc-gallery__item > a.sc-gallery__card > p.pc-card__gl-datetime
Read the latest news. Get the Apple Developer app. Follow us on bilibili, Linke… div.footer-content > section.footer-mini > div.footer-mini-news > div.copy
Read the latest news. section.footer-mini > div.footer-mini-news > div.copy > div.footer-mini-legal-link
Get the Apple Developer app. section.footer-mini > div.footer-mini-news > div.copy > div.footer-mini-legal-link
Light div.content > div.color-scheme-toggle > label > div.text
Dark div.content > div.color-scheme-toggle > label > div.text
Copyright © 2026 Apple Inc. All rights reserved. div.footer-content > section.footer-mini > div.footer-mini-legal > div.footer-mini-legal-copyright

Low-contrast text is difficult or impossible for many users to read. Link text that is discernible improves the experience for users with low vision. Learn how to make links distinguishable.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Apple Inc. section.footer-mini > div.footer-mini-legal > div.footer-mini-legal-copyright > a

These are opportunities to improve the legibility of your content.

Navigation

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
App Review appointment li.sc-gallery__item > a.sc-gallery__card > div.pc-card__gl-top > h5.pc-card__title
Join the Apple Developer Program to reach customers around the world on the App… div.section-content > div.row > div.column > h5.subhead

These are opportunities to improve keyboard navigation in your application.

Names and labels

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
main.main > section.section > div.unit-wrapper > a.unit-link main.main > section.section > div.unit-wrapper > a.unit-link

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

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
Privacy Policy section.footer-mini > div.footer-mini-legal > div.footer-mini-legal-links > a.footer-mini-legal-link

These items highlight common accessibility best practices.

Visible text labels that do not match the accessible name can result in a confusing experience for screen reader users. Learn more about accessible names.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Try it now div.caption-container > div.caption-container-inner > div.media-card-gallery-ctas > a.button
○Interactive controls are keyboard focusable
○Interactive elements indicate their purpose and state
○The page has a logical tab order
○Visual order on the page follows DOM order
○User focus is not accidentally trapped in a region
○The user's focus is directed to new content added to the page
○HTML5 landmark elements are used to improve navigation
○Offscreen content is hidden from assistive technology
○Custom controls have associated labels
○Custom controls have ARIA roles
●`[aria-*]` attributes match their roles
●`[aria-hidden="true"]` is not present on the document `<body>`
●`[role]`s have all required `[aria-*]` attributes
●`[role]`s are contained by their required parent element
●`[aria-*]` attributes have valid values
●`[aria-*]` attributes are valid and not misspelled
●Buttons have an accessible name
●Image elements have `[alt]` attributes
●Form elements have associated labels
●`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.
●Select elements have associated label elements.
●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
●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
●`[lang]` attributes have a valid value
●`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.
●Document has a main landmark.
●Deprecated ARIA roles were not used
●Uses ARIA roles only on compatible elements
○`[accesskey]` values are unique
○`button`, `link`, and `menuitem` elements have accessible names
○Elements with `role="dialog"` or `role="alertdialog"` have accessible names.
○ARIA input fields have accessible names
○ARIA `meter` elements have accessible names
○ARIA `progressbar` elements have accessible names
○Elements with 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
○Input buttons have discernible text.
○`<input type="image">` elements have `[alt]` text
○The document does not use `<meta http-equiv="refresh">`
○`<object>` elements have alternate text
○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.
○`<video>` elements contain a `<track>` element with `[kind="captions"]`
○Tables have different content in the summary attribute and `<caption>`.
○All heading elements contain content.
○Image elements do not have `[alt]` attributes that are redundant text.
○Identical links have the same purpose.
○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.
96

Best Practices

General

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

SourceDescription
Failed to load resource: the server responded with a status of 401 (Unauthorized)
Failed to load resource: the server responded with a status of 401 (Unauthorized)
●Uses HTTPS
●Avoids deprecated APIs
●Avoids third-party cookies
●Allows users to paste into input fields
●Avoids requesting the geolocation permission on page load
●Avoids requesting the notification permission on page load
●Displays images with correct aspect ratio
●Serves images with appropriate resolution
●Page has the HTML doctype
●Properly defines charset
●No issues in the `Issues` panel in Chrome Devtools
●Ensure CSP is effective against XSS attacks
●Use a strong HSTS policy
●Ensure proper origin isolation with COOP
●Mitigate DOM-based XSS with Trusted Types
●Detected JavaScript libraries
●Page has valid source maps
○Redirects HTTP traffic to HTTPS
○Mitigate clickjacking with XFO or CSP
92

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

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 destinationLink Text
www.apple.com/apple-events/Learn more
www.apple.com/apple-events/Learn more

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
●Document has a meta description
●Page has successful HTTP status code
●Links are crawlable
●robots.txt is valid
●Image elements have `[alt]` attributes
●Document has a valid `hreflang`
●Document has a valid `rel=canonical`

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