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/202504.1.0/otBannerSdk.js	86400.0 s	117.9 KiB
cdn.cookielaw.org/scripttemplates/otSDKStub.js	86400.0 s	9.1 KiB
/logos/2217e117-526b-4696-8a98-8c402f8f2b81/e9bcc9b6-6c71...	86400.0 s	2.7 KiB
cdn.cookielaw.org/logos/static/powered_by_logo.svg	86400.0 s	2.6 KiB
cdn.cookielaw.org/consent/560a8aa4-c54c-486f-9bc4-35a3f22bacd9/OtAutoBlock.js	86400.0 s	2.3 KiB
/a?id=GTM-TRZFQ4N&v=3&t=t&pid=394540974&gtm=45He64h1v8334...	0.0 ms	11 B
/a?id=GTM-TRZFQ4N&v=3&t=t&pid=394540974&gtm=45He64h1v8334...	0.0 ms	11 B
/a?id=GTM-TRZFQ4N&v=3&t=t&pid=394540974&gtm=45He64h1v8334...	0.0 ms	11 B
/a?id=GTM-TRZFQ4N&v=3&t=t&pid=394540974&gtm=45He64h1v8334...	0.0 ms	11 B
/a?id=GTM-TRZFQ4N&v=3&t=t&pid=394540974&gtm=45He64h1v8334...	0.0 ms	11 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.

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
www.uptodate.com/app/assets/NotoSans-SemiBold-eeohmkRK.woff2	185 ms
www.uptodate.com/app/assets/wk-icons-8dBf3Vus.woff2	75 ms
www.uptodate.com/app/assets/NotoSans-Bold-CjI8rmzb.woff2	70 ms
www.uptodate.com/app/assets/NotoSans-Regular-CUnezwo1.woff2	65 ms
www.uptodate.com/app/assets/NotoSans-Light-DzqmUfbq.woff2	65 ms
www.uptodate.com/app/assets/wk-icons-open-I9AnqcVf.woff	35 ms

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
www.uptodate.com/app/assets/utd-all-C4EXBBMH.css	218.7 KiB	3.2 s

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Protocol
www.uptodate.com/login	http/1.1
www.uptodate.com/app/dist/DOM-Cws02s0j.min.js	http/1.1
www.uptodate.com/app/dist/epic-ClRhenuO.min.js	http/1.1
www.uptodate.com/app/assets/utd-all-C4EXBBMH.css	http/1.1
www.uptodate.com/app/dist/index-CEWs5uCT.min.js	http/1.1
www.uptodate.com/app/dist/vendor-DMdb3ILA.min.js	http/1.1
www.uptodate.com/app/dist/utd-all-BtFJPR2f.min.js	http/1.1
www.uptodate.com/app/utd-menu/utd-icon.png	http/1.1
www.uptodate.com/app/dist/pace-B_2Z1FtK.min.js	http/1.1
www.uptodate.com/app/utd-menu/utd-icon-redesign.png	http/1.1
www.uptodate.com/services/app/init/json?id=YXBwQ29udGFpbmVy	http/1.1
www.uptodate.com/app/utd-menu/wk-wheel-icon.svg	http/1.1
www.uptodate.com/app/utd-menu/utd-logo.svg	http/1.1
www.uptodate.com/app/assets/NotoSans-Regular-CUnezwo1.woff2	http/1.1
www.uptodate.com/app/assets/WK-Logo-7lXiX5v8.svg	http/1.1
www.uptodate.com/app/assets/NotoSans-Bold-CjI8rmzb.woff2	http/1.1
www.uptodate.com/app/assets/wk-icons-8dBf3Vus.woff2	http/1.1
www.uptodate.com/app/assets/NotoSans-SemiBold-eeohmkRK.woff2	http/1.1
www.uptodate.com/services/app/localization/file?lang=fr	http/1.1
/services/app/event/login/json?source=login-subscribe-vie...	http/1.1
www.uptodate.com/services/app/config/footer/json	http/1.1
www.uptodate.com/contents/assets/css/UTD_gx_gen.css	http/1.1
www.uptodate.com/app/assets/microsoft-logo-blue-BeURMre4.svg	http/1.1
www.uptodate.com/app/assets/open-athens-logo-purple-Dep7k9zT.svg	http/1.1
www.uptodate.com/app/assets/wk-icons-open-I9AnqcVf.woff	http/1.1
www.uptodate.com/app/assets/NotoSans-Light-DzqmUfbq.woff2	http/1.1

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

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: 2.7 s

URL	Time Spent
uptodate.com/	1.3 s
www.uptodate.com/	848 ms
www.uptodate.com/index	548 ms
www.uptodate.com/login	0.0 ms

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: 1.3 s 232.1 KiB

URL	Transfer Size	Est Savings
www.uptodate.com/app/assets/utd-all-C4EXBBMH.css	216.8 KiB	213.4 KiB
	22.0 KiB	18.8 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: 10.4 s 1.7 MiB

URL	Transfer Size	Est Savings
www.uptodate.com/app/dist/utd-all-BtFJPR2f.min.js	1.3 MiB	978.9 KiB
www.uptodate.com/app/dist/vendor-DMdb3ILA.min.js	677.2 KiB	386.8 KiB
www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js	361.8 KiB	175.7 KiB
cdn.cookielaw.org/scripttemplates/202504.1.0/otBannerSdk.js	117.8 KiB	60.4 KiB
www.googletagmanager.com/gtm.js?id=GTM-TRZFQ4N&gtm=4e64h1	152.5 KiB	58.2 KiB
www.googletagmanager.com/gtm.js?id=GTM-53VFLLN	152.8 KiB	56.2 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.

URL	Total CPU Time	Script Evaluation	Script Parse
www.googletagmanager.com/gtm.js?id=GTM-53VFLLN	1.2 s	1.2 s	42 ms
Unattributable	663 ms	205 ms	0.0 ms
www.uptodate.com/app/dist/pace-B_2Z1FtK.min.js	645 ms	567 ms	0.2 ms
www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js	615 ms	528 ms	72 ms
www.googletagmanager.com/gtm.js?id=GTM-TRZFQ4N&gtm=4e64h1	564 ms	500 ms	39 ms
www.uptodate.com/login	502 ms	4.0 ms	1.4 ms
cdn.cookielaw.org/scripttemplates/202504.1.0/otBannerSdk.js	266 ms	190 ms	42 ms
www.uptodate.com/app/assets/utd-all-C4EXBBMH.css	90 ms	0.0 ms	0.0 ms

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Category	Time Spent
Script Evaluation	3.3 s
Other	730 ms
Style & Layout	350 ms
Script Parsing & Compilation	208 ms
Parse HTML & CSS	83 ms
Garbage Collection	73 ms
Rendering	44 ms

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failure reason	Failure type
Pages with cache-control:no-store header cannot enter back/forward cache.	Actionable
Pages whose main resource has cache-control:no-store cannot enter back/forward cache.	Not actionable
Back/forward cache is disabled because some JavaScript network request received resource with Cache-Control: no-store header.	Not actionable

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.uptodate.com/app/dist/utd-all-BtFJPR2f.min.js	1.3 MiB
www.uptodate.com/app/dist/vendor-DMdb3ILA.min.js	679.3 KiB
www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js	362.4 KiB
www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js	362.4 KiB
www.uptodate.com/app/assets/utd-all-C4EXBBMH.css	218.7 KiB
www.uptodate.com/app/assets/NotoSans-SemiBold-eeohmkRK.woff2	167.9 KiB
www.uptodate.com/app/assets/NotoSans-Regular-CUnezwo1.woff2	165.3 KiB
www.uptodate.com/app/assets/NotoSans-Light-DzqmUfbq.woff2	164.8 KiB
www.uptodate.com/app/assets/NotoSans-Bold-CjI8rmzb.woff2	163.4 KiB
www.googletagmanager.com/gtm.js?id=GTM-53VFLLN	153.0 KiB

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL
UpToDate `div.floating-labels-form > div > a.wk-logo > img.utd-logo`	www.uptodate.com/app/utd-menu/utd-logo.svg

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

●Layout shift culprits

●Optimize DOM size

●Forced reflow

●Improve image delivery

●LCP breakdown

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●Avoid long main-thread tasks 20 long tasks found

●Avoid non-composited animations 1 animated element found

●Network Requests

●Network Round Trip Times 180 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 40 ms

●Avoid large layout shifts 1 layout shift found

○INP breakdown

○LCP request discovery

○User Timing marks and measures

Accessibility

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

Best practices

Disabling zooming is problematic for users with low vision who rely on screen magnification to properly see the contents of a web page. Learn more about the viewport meta tag.

Why this matters

Informational: a Permissions-Policy directive showing feature -> allowed origins.

Source: MDN Permissions-Policy

Failing Elements
head > meta `head > meta`

These items highlight common accessibility best practices.

Navigation

A value greater than 0 implies an explicit navigation ordering. Although technically valid, this often creates frustrating experiences for users who rely on assistive technologies. Learn more about the `tabindex` attribute.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Close `div.visuallyHidden > div.username-tooltip-box > div.tooltip-action > button.utd-button`

These are opportunities to improve keyboard navigation in your application.

○Interactive controls are keyboard focusable

○Interactive elements indicate their purpose and state

○The page has a logical tab order

○Visual order on the page follows DOM order

○User focus is not accidentally trapped in a region

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

○HTML5 landmark elements are used to improve navigation

○Offscreen content is hidden from assistive technology

○Custom controls have associated labels

○Custom controls have ARIA roles

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

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

●`[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

●Form elements have associated labels

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

●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

●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 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

●Touch targets have sufficient size and spacing.

●Heading elements appear in a sequentially-descending order

●Document has a main landmark.

●Deprecated ARIA roles were not used

○`[accesskey]` values are unique

○ARIA input fields have accessible names

○ARIA `meter` elements have accessible names

○ARIA `progressbar` elements have accessible names

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

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

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

○ARIA toggle fields have accessible names

○ARIA `tooltip` elements have accessible names

○ARIA `treeitem` elements have accessible names

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

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

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

○ARIA IDs are unique

○No form fields have multiple labels

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

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

○Input buttons have discernible text.

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

○Links are distinguishable without relying on color.

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

○`<object>` elements have alternate text

○Select elements have associated label elements.

○Skip links are focusable.

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

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

○`[lang]` attributes have a valid value

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

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

○All heading elements contain content.

○Uses ARIA roles only on compatible elements

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

○Identical links have the same purpose.

○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.

100

Best Practices

●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 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 DOM-based XSS with Trusted Types

●Page has valid source maps

○Redirects HTTP traffic to HTTPS

○Mitigate clickjacking with XFO or CSP

○Detected JavaScript libraries

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.

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 have descriptive text

●Links are crawlable

●robots.txt is valid

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`

●Document has a valid `rel=canonical`