Lighthouse Mobile

· 0 checks — Mobile 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.

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
cdn.cookielaw.org/scripttemplates/202601.2.0/otBannerSdk.js	86400.0 s	128.4 KiB
stackoverflow.com/Content/Img/favicons-sprite32.png?v=91e30776b0a0	604800.0 s	275.2 KiB
stackoverflow.com/Content/Js/full-anon.en.js?v=037e97b07fca	604800.0 s	128.8 KiB
stackoverflow.com/Content/Shared/stacks.css?v=b2264ccf0463	604800.0 s	110.2 KiB
cdn.cookielaw.org/scripttemplates/202601.2.0/otGPP.js	86400.0 s	22.2 KiB
/cdn-cgi/challenge-platform/h/b/scripts/jsd/625261456364/...	14400.0 s	11.8 KiB
stackoverflow.com/Content/Sites/stackoverflow/primary.css?v=880dfade9e7f	604800.0 s	74.3 KiB
cdn.cookielaw.org/scripttemplates/202601.2.0/otTCF.js	86400.0 s	17.8 KiB
cdn.cookielaw.org/scripttemplates/otSDKStub.js	86400.0 s	9.1 KiB
stackoverflow.com/Content/Js/webpack-chunks/svelte.en.js?v=f773033c4e0b	604800.0 s	32.1 KiB
/Content/Js/third-party/npm/@stackoverflow/stacks/dist/js...	604800.0 s	30.5 KiB
stackoverflow.com/Content/Js/stub.en.js?v=e307fb81e738	604800.0 s	18.1 KiB
stackoverflow.com/Content/Js/questions/userQuestionList.en.js?v=8b4317437ce2	604800.0 s	16.6 KiB
/avatar/77927b8f043dd7bbb27f0018d2bd1624?s=32&d=identicon...	300.0 s	1.7 KiB
stackoverflow.com/Content/Js/islands/homepage-wizard.en.js?v=a74b3480697c	604800.0 s	16.1 KiB
www.gravatar.com/avatar/fdc1f4bd9f3118fff33a160e9efdb61e?s=32&d=identicon&r=PG	300.0 s	1.5 KiB
/avatar/83389645b9b5d98bffa1362da28b4711?s=32&d=identicon...	300.0 s	1.4 KiB
/avatar/d0fc8123a9edf2177fb66e66bf28d259?s=32&d=identicon...	300.0 s	1.4 KiB
stackoverflow.com/Content/Js/webpack-chunks/stacks-svelte.en.js?v=297d3b9a88f6	604800.0 s	12.8 KiB
stackoverflow.com/Content/Js/questions/list.en.js?v=2175cf260ad4	604800.0 s	12.7 KiB
/avatar/e831ce9803c96b75355e39b5371f5b70?s=32&d=identicon...	300.0 s	1.3 KiB
/avatar/941d88e38254d09d0d6670db673abf4b?s=32&d=identicon...	300.0 s	1.2 KiB
/avatar/829234be3685d327f5beed97416ec0af?s=32&d=identicon...	300.0 s	1.2 KiB
www.gravatar.com/avatar/20c1f68b1bb5c87878c69d5442855a28?s=32&d=identicon&r=PG	300.0 s	1.2 KiB
/avatar/366efa98bb157cd99284ea03b15fdca6?s=32&d=identicon...	300.0 s	1.2 KiB
/avatar/3f0874bd4af2ca1f3566d293d21a4961?s=32&d=identicon...	300.0 s	1.2 KiB
lngtd.com/stackoverflow.js	900.0 s	1.2 KiB
/avatar/9875608b463550ab1a13be2f2c30a9b3?s=32&d=identicon...	300.0 s	1.0 KiB
www.gravatar.com/avatar/4288427122ae357b092954b12d139311?s=32&d=identicon&r=PG	300.0 s	1.0 KiB
/avatar/c4c291308f93584ca1d125f2b9c0ccfa?s=32&d=identicon...	300.0 s	995 B
stackoverflow.com/Content/Js/webpack-chunks/9366.en.js?v=c8d4e4e64bf3	604800.0 s	8.5 KiB
stackoverflow.com/Content/Js/islands/signup-modal.en.js?v=f64ec881ea96	604800.0 s	8.4 KiB
/Content/Js/webpack-chunks/stacks-svelte-labs.en.js?v=b9c...	604800.0 s	7.7 KiB
cdn.cookielaw.org/scripttemplates/gpp.stub.js	86400.0 s	1.9 KiB
stackoverflow.com/Content/Js/webpack-chunks/7663.en.js?v=c67f16729ba4	604800.0 s	7.4 KiB
stackoverflow.com/Content/Js/webpack-chunks/9001.en.js?v=3a153d433746	604800.0 s	5.2 KiB
stackoverflow.com/Content/Js/webpack-chunks/8339.en.js?v=4cb8dd34a7f9	604800.0 s	4.9 KiB
stackoverflow.com/Content/Js/topbar/top-bar-events.en.js?v=9f5a4d15c5cd	604800.0 s	4.8 KiB
stackoverflow.com/Content/Shared/Channels/channels.css?v=d431b1be5a03	604800.0 s	4.7 KiB
stackoverflow.com/px.js?ch=2	14400.0 s	547 B
stackoverflow.com/px.js?ch=1	14400.0 s	369 B
stackoverflow.com/Content/Js/google-analytics.en.js?v=48615a9a9bc4	604800.0 s	2.4 KiB
stackoverflow.com/Content/Js/webpack-chunks/3696.en.js?v=7ef09fb6562b	604800.0 s	2.2 KiB
stackoverflow.com/Content/Js/islands/one-tap.en.js?v=102f0378a2cf	604800.0 s	1.7 KiB
stackoverflow.com/Content/Js/webpack-chunks/620.en.js?v=a432091814d8	604800.0 s	1.6 KiB
/Content/Sites/stackoverflow/Img/subcommunities/ci-cd.svg...	604800.0 s	1.5 KiB
stackoverflow.com/Content/Js/sprinkles/left-nav-events.en.js?v=2ac13fd60bf6	604800.0 s	1.1 KiB
stackoverflow.com/Content/Js/sprinkles/cookie-consent.en.js?v=7ee6963139c5	604800.0 s	1.1 KiB
/Content/Sites/stackoverflow/Img/subcommunities/google-cl...	604800.0 s	1.0 KiB
/Content/Sites/stackoverflow/Img/subcommunities/php.svg?v...	604800.0 s	1004 B
/Content/Sites/stackoverflow/Img/subcommunities/mobile-de...	604800.0 s	817 B
stackoverflow.com/Content/Js/webpack-chunks/2458.en.js?v=33cc3da05f78	604800.0 s	796 B
stackoverflow.com/Content/Js/webpack-chunks/5102.en.js?v=77170ebd8b1b	604800.0 s	728 B
stackoverflow.com/Content/Sites/stackoverflow/Img/icon-48.png?v=6452e6a98212	604800.0 s	457 B

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:17.149 source:map[column:27323 line:2 type:source-location url:https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.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:1.391 source:map[column:50335 line:1 type:source-location url:https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js urlProvider:network]] map[reflowTime:0.655 source:map[column:50393 line:1 type:source-location url:https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js urlProvider:network]] map[reflowTime:0.521 source:map[column:50457 line:1 type:source-location url:https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js urlProvider:network]] map[reflowTime:5.09 source:map[column:49637 line:1 type:source-location url:https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js urlProvider:network]] map[reflowTime:21.205 source:map[column:49615 line:1 type:source-location url:https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js urlProvider:network]] map[reflowTime:0.812 source:map[column:51395 line:1 type:source-location url:https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js urlProvider:network]] map[reflowTime:0.82 source:map[column:79427 line:1 type:source-location url:https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js urlProvider:network]] map[reflowTime:0.35 source:map[column:5984 line:0 type:source-location url:https://stackoverflow.com/Content/Js/questions/userQuestionList.en.js?v=8b4317437ce2 urlProvider:network]] map[reflowTime:0.456 source:map[column:83946 line:1 type:source-location url:https://ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js urlProvider:network]]]

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
stackoverflow.com/px.js?ch=1	369 B
stackoverflow.com/px.js?ch=2	547 B
cdn.cookielaw.org/scripttemplates/gpp.stub.js	1.9 KiB	764 ms
cdn.cookielaw.org/scripttemplates/otSDKStub.js	9.1 KiB	150 ms
stackoverflow.com/Content/Shared/stacks.css?v=b2264ccf0463	110.2 KiB	1.4 s
ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js	30.4 KiB	1.2 s
stackoverflow.com/Content/Sites/stackoverflow/primary.css?v=880dfade9e7f	74.3 KiB	451 ms
stackoverflow.com/Content/Js/google-analytics.en.js?v=48615a9a9bc4	2.4 KiB
stackoverflow.com/Content/Shared/Channels/channels.css?v=d431b1be5a03	4.7 KiB
stackoverflow.com/Content/Js/stub.en.js?v=e307fb81e738	18.1 KiB	150 ms

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#hot-network-questions > ul > li.js-hidden > div.favicon `div#hot-network-questions > ul > li.js-hidden > div.favicon`	stackoverflow.com/Content/Img/favicons-sprite32.png?v=91e30776b0a0	274.8 KiB	200.7 KiB

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

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.

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: 783 ms

URL	Time Spent
stackoverflow.com/	783 ms
stackoverflow.com/questions	0.0 ms

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

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: 720 ms 170.9 KiB

URL	Transfer Size	Est Savings
stackoverflow.com/Content/Shared/stacks.css?v=b2264ccf0463	110.1 KiB	102.6 KiB
stackoverflow.com/Content/Sites/stackoverflow/primary.css?v=880dfade9e7f	74.2 KiB	68.3 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: 2.9 s 679.3 KiB

URL	Transfer Size	Est Savings
s.lngtdv.com/prebid/stackoverflow/prebid10.27.0.1774971607.min.js	171.8 KiB	141.2 KiB
/pagead/managed/js/gpt/m202604010101/pubads_impl.js?cb=31...	182.4 KiB	137.6 KiB
stackoverflow.com/Content/Js/full-anon.en.js?v=037e97b07fca	128.7 KiB	94.8 KiB
cdn.cookielaw.org/scripttemplates/202601.2.0/otBannerSdk.js	128.2 KiB	71.9 KiB
accounts.google.com/gsi/client	92.7 KiB	69.9 KiB
www.googletagmanager.com/gtag/js?id=G-WCZ03SZFCQ	153.0 KiB	59.1 KiB
s.lngtdv.com/stackoverflow/default.1775148653.js	71.0 KiB	41.1 KiB
stackoverflow.com/Content/Js/webpack-chunks/svelte.en.js?v=f773033c4e0b	32.0 KiB	31.8 KiB
stackoverflow.com/Content/Js/webpack-chunks/svelte.en.js?v=f773033c4e0b	32.0 KiB	31.8 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
stackoverflow.com/questions	1.2 s	106 ms	28 ms
Unattributable	974 ms	19 ms	0.0 ms
cdn.cookielaw.org/scripttemplates/202601.2.0/otGPP.js	936 ms	825 ms	37 ms
stackoverflow.com/Content/Js/islands/homepage-wizard.en.js?v=a74b3480697c	614 ms	483 ms	7.5 ms
www.googletagmanager.com/gtag/js?id=G-WCZ03SZFCQ	468 ms	383 ms	81 ms
s.lngtdv.com/stackoverflow/default.1775148653.js	449 ms	370 ms	59 ms
stackoverflow.com/cdn-cgi/challenge-platform/scripts/jsd/main.js	447 ms	415 ms	4.6 ms
/pagead/managed/js/gpt/m202604010101/pubads_impl.js?cb=31...	396 ms	293 ms	96 ms
stackoverflow.com/Content/Js/stub.en.js?v=e307fb81e738	328 ms	191 ms	8.0 ms
cdn.cookielaw.org/scripttemplates/202601.2.0/otBannerSdk.js	318 ms	140 ms	101 ms
s.lngtdv.com/prebid/stackoverflow/prebid10.27.0.1774971607.min.js	308 ms	213 ms	93 ms
stackoverflow.com/Content/Js/islands/signup-modal.en.js?v=f64ec881ea96	250 ms	214 ms	3.4 ms
stackoverflow.com/Content/Js/full-anon.en.js?v=037e97b07fca	246 ms	150 ms	80 ms
stackoverflow.com/Content/Js/islands/one-tap.en.js?v=102f0378a2cf	147 ms	75 ms	1.0 ms
pagead2.googlesyndication.com/tag/js/gpt.js	138 ms	116 ms	21 ms
ajax.googleapis.com/ajax/libs/jquery/3.7.1/jquery.min.js	129 ms	108 ms	16 ms
/Content/Js/third-party/npm/@stackoverflow/stacks/dist/js...	109 ms	84 ms	20 ms
cdn.cookielaw.org/scripttemplates/otSDKStub.js	109 ms	92 ms	4.9 ms
accounts.google.com/gsi/client	88 ms	41 ms	46 ms
stackoverflow.com/Content/Js/webpack-chunks/9001.en.js?v=3a153d433746	83 ms	28 ms	1.9 ms
cdn.cookielaw.org/scripttemplates/gpp.stub.js	69 ms	60 ms	2.1 ms
stackoverflow.com/Content/Js/webpack-chunks/svelte.en.js?v=f773033c4e0b	65 ms	18 ms	45 ms
stackoverflow.com/Content/Js/questions/userQuestionList.en.js?v=8b4317437ce2	57 ms	13 ms	7.1 ms
stackoverflow.com/Content/Js/webpack-chunks/7663.en.js?v=c67f16729ba4	50 ms	33 ms	2.8 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	4.5 s
Style & Layout	1.1 s
Other	1.1 s
Script Parsing & Compilation	832 ms
Parse HTML & CSS	328 ms
Garbage Collection	158 ms
Rendering	106 ms

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

●Layout shift culprits

●Optimize DOM size

●Font display

●LCP breakdown

●Modern HTTP

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●Avoids enormous network payloads Total size was 1,980 KiB

●User Timing marks and measures 5 user timings

●Avoid long main-thread tasks 20 long tasks found

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

●Page didn't prevent back/forward cache restoration

●Network Requests

●Network Round Trip Times 30 ms

●Server Backend Latencies 30 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Initial server response time was short Root document took 140 ms

○INP breakdown

○LCP request discovery

○Avoid non-composited animations

○Avoid large layout shifts

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
15 `div#content > div#mainbar > div.s-pagination > a.s-pagination--item`

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
Why is Spring Boot still used in large-scale systems despite newer backend fram… `div.bb > div#question-summary-79920167 > div.s-post-summary--content > h3.s-post-summary--content-title`
Hot Network Questions `div#content > div#sidebar > div#hot-network-questions > h4`

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
body.questions-page > header.s-topbar > div.s-topbar--container > a.s-topbar--menu-btn `body.questions-page > header.s-topbar > div.s-topbar--container > a.s-topbar--menu-btn`
div.s-post-summary--content > div.s-post-summary--meta > div.s-post-summary--meta-tags > a.themed `div.s-post-summary--content > div.s-post-summary--meta > div.s-post-summary--meta-tags > a.themed`
div.s-post-summary--content > div.s-post-summary--meta > div.s-post-summary--meta-tags > a.themed `div.s-post-summary--content > div.s-post-summary--meta > div.s-post-summary--meta-tags > a.themed`
div.s-post-summary--content > div.s-post-summary--meta > div.s-post-summary--meta-tags > a.themed `div.s-post-summary--content > div.s-post-summary--meta > div.s-post-summary--meta-tags > a.themed`

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
BUSINESS `nav.site-footer--nav > div.site-footer--col > h5.-title > a.js-gps-track`
Stack Internal `div.site-footer--col > ul.-list > li > a.js-gps-track`
Technology `div > ul.-list > li > a.-link`
Business `div > ul.-list > li > a.-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>`

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

●`[role]` values are valid

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

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

●Buttons have an accessible name

●Image elements have `[alt]` attributes

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

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

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

●`[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

●Document has a main landmark.

●Deprecated ARIA roles were not used

●ARIA IDs are unique

●Uses ARIA roles only on compatible elements

●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

○ARIA input fields have accessible names

○ARIA `meter` elements have accessible names

○ARIA `progressbar` elements have accessible names

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

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

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

○ARIA toggle fields have accessible names

○ARIA `tooltip` elements have accessible names

○ARIA `treeitem` elements have accessible names

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

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

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

○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.

○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

User Experience

Image natural dimensions should be proportional to the display size and the pixel ratio to maximize image clarity. Learn how to provide responsive images.

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL	Displayed size	Actual size	Expected size
site logo `div.s-modal--dialog > h1#signup-modal-title > div.s-modal--header > img.h48`	stackoverflow.com/Content/Sites/stackoverflow/Img/icon-48.png?v=6452e6a98212	48 x 48	48 x 48	72 x 72

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
SharedStorage	stackoverflow.com/cdn-cgi/challenge-platform/scripts/jsd/main.js
StorageType.persistent is deprecated. Please use standardized navigator.storage instead.	stackoverflow.com/cdn-cgi/challenge-platform/scripts/jsd/main.js
Fledge	stackoverflow.com/cdn-cgi/challenge-platform/scripts/jsd/main.js

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Source	Description
stackoverflow.com/questions	`Not signed in with the identity provider.`

●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

●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

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
/internal/?utm_medium=referral&utm_source=stackoverflow-c...	Learn more
/internal/?utm_medium=referral&utm_source=stackoverflow-c...	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

●Page has successful HTTP status code

●Links are crawlable

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`

○robots.txt is valid

○Document has a valid `rel=canonical`