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.

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
assets.adobedtm.com/59640f9fa510/7cad07cf7779/launch-a215d9c51521.min.js	3600.0 s	60.1 KiB
/cochrane-theme/css/custom.css?browserId=other&themeId=co...	86400.0 s	93.4 KiB
www.cochranelibrary.com/cochrane-theme/fonts/fontawesome-webfont.woff2?v=4.6.3	86400.0 s	70.4 KiB
platform.twitter.com/widgets.js	1800.0 s	27.3 KiB
www.google-analytics.com/analytics.js	7200.0 s	20.9 KiB
www.cochranelibrary.com/cochrane-theme/fonts/fontawesome-alloy.woff	86400.0 s	36.7 KiB
/cdn-cgi/challenge-platform/h/b/scripts/jsd/0b8fb825cb67/...	14400.0 s	11.9 KiB
injections.readcube.com/config.json	0.0 ms	5.4 KiB
crossmark-cdn.crossref.org/widget/v2.0/widget.js	0.0 ms	5.1 KiB
script.crazyegg.com/pages/scripts/0056/6375.js	300.0 s	2.7 KiB
d1bxh8uas1mnw7.cloudfront.net/assets/embed.js	0.0 ms	1.0 KiB
static.addtoany.com/menu/page.js	86400.0 s	2.2 KiB
content.readcube.com/cochrane/epdf_linker.js	60.0 s	871 B
/html/js/liferay/available_languages.jsp?browserId=other&...	86400.0 s	707 B
www.cochranelibrary.com/cochrane-theme/images/social/bluesky-sm.svg	86400.0 s	568 B
static.addtoany.com/menu/svg/icons/x.js	864000.0 s	775 B

Layout shifts occur when elements move absent any user interaction. Investigate the causes of layout shifts, such as elements being added, removed, or their fonts changing as the page loads.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:node label:Element subItemsHeading:map[key:extra] valueType:node] map[granularity:0.001 key:score label:Layout shift score subItemsHeading:map[key:cause valueType:text] valueType:numeric]]

items: [map[node:map[type:text value:Total] score:0.347777] map[node:map[boundingRect:map[bottom:1445 height:430 left:55 right:1295 top:1015 width:1240] lhId:page-6-DIV nodeLabel:Topics Blood and immune system conditions Cancer Cardiovascular conditions Cell… path:5,HTML,3,BODY,1,DIV,6,DIV,0,DIV,1,DIV selector:div.site-container > div#content > div#main-content > div.container snippet:<div class="container"> type:node] score:0.346331 subItems:map[items:[map[cause:Web font extra:map[type:url value:https://fonts.gstatic.com/s/sourcesanspro/v23/6xK3dSBYKcSV-LCoeQqfX1RYOo3qOK7lujVj9w.woff2]] map[cause:Web font extra:map[type:url value:https://fonts.gstatic.com/s/sourcesanspro/v23/6xKydSBYKcSV-LCoeQqfX1RYOo3i54rwlxdu3cOWxw.woff2]] map[cause:Web font extra:map[type:url value:https://fonts.gstatic.com/s/sourcesanspro/v23/6xKydSBYKcSV-LCoeQqfX1RYOo3ig4vwlxdu3cOWxw.woff2]]] type:subitems]] map[node:map[boundingRect:map[bottom:100 height:85 left:852 right:1275 top:15 width:423] lhId:page-11-DIV nodeLabel:Basic Search Title Abstract Keyword Browse Advanced search path:5,HTML,3,BODY,1,DIV,3,HEADER,0,DIV,1,DIV selector:div.site-container > header > div.container > div.desktop-search snippet:<div class="desktop-search basic-search-container"> type:node] score:0.001446]]

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.cochranelibrary.com/cochrane-theme/fonts/fontawesome-webfont.woff2?v=4.6.3	60 ms
www.cochranelibrary.com/cochrane-theme/fonts/fontawesome-alloy.woff	55 ms
/s/sourcesanspro/v23/6xKydSBYKcSV-LCoeQqfX1RYOo3ig4vwlxdu...	45 ms
/s/sourcesanspro/v23/6xKydSBYKcSV-LCoeQqfX1RYOo3i54rwlxdu...	30 ms
/s/sourcesanspro/v23/6xK3dSBYKcSV-LCoeQqfX1RYOo3qOK7lujVj...	25 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:Source valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]

items: [map[reflowTime:88.784 source:map[type:text value:[unattributed]]] map[reflowTime:1.042 source:map[column:57310 line:1 type:source-location url:https://www.cochranelibrary.com/cochrane-theme/js/theme.js?t=1776315578000 urlProvider:network]] map[reflowTime:0.201 source:map[column:57439 line:1 type:source-location url:https://www.cochranelibrary.com/cochrane-theme/js/theme.js?t=1776315578000 urlProvider:network]] map[reflowTime:0.128 source:map[column:57749 line:1 type:source-location url:https://www.cochranelibrary.com/cochrane-theme/js/theme.js?t=1776315578000 urlProvider:network]] map[reflowTime:0.159 source:map[column:57812 line:1 type:source-location url:https://www.cochranelibrary.com/cochrane-theme/js/theme.js?t=1776315578000 urlProvider:network]] map[reflowTime:0.679 source:map[column:58021 line:1 type:source-location url:https://www.cochranelibrary.com/cochrane-theme/js/theme.js?t=1776315578000 urlProvider:network]] map[reflowTime:1.06 source:map[column:58096 line:1 type:source-location url:https://www.cochranelibrary.com/cochrane-theme/js/theme.js?t=1776315578000 urlProvider:network]] map[reflowTime:0.394 source:map[column:94446 line:1 type:source-location url:https://www.cochranelibrary.com/cochrane-theme/js/theme.js?t=1776315578000 urlProvider:network]] map[reflowTime:1.281 source:map[column:505484 line:1 type:source-location url:https://www.cochranelibrary.com/cochrane-theme/js/theme.js?t=1776315578000 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
Multiple `article.mini-hero > a.mini-hero-module > div.mini-hero-image-wrapper > img.mini-hero-image`	www.cochranelibrary.com/image/journal/article?img_id=486670274&t=1774877752172	36.2 KiB	34.7 KiB
Maternal, `article.mini-hero > a.mini-hero-module > div.mini-hero-image-wrapper > img.mini-hero-image`	www.cochranelibrary.com/image/journal/article?img_id=486670272&t=1774877752093	32.6 KiB	31.2 KiB
Climate `article.mini-hero > a.mini-hero-module > div.mini-hero-image-wrapper > img.mini-hero-image`	www.cochranelibrary.com/image/journal/article?img_id=486670278&t=1774877752328	27.0 KiB	25.8 KiB
Infectious `article.mini-hero > a.mini-hero-module > div.mini-hero-image-wrapper > img.mini-hero-image`	www.cochranelibrary.com/image/journal/article?img_id=486670276&t=1774877752253	20.4 KiB	19.5 KiB
Image 3 `div.journal-content-article > div.external-link-row > a > img`	www.cochranelibrary.com/cochrane-theme/images/external_links/our_journal.png	7.0 KiB	4.7 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-5-IMG

nodeLabel: Main Banner Image

path: 5,HTML,3,BODY,1,DIV,6,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,1,DIV,1,SECTION,1,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,A,0,IMG

selector: div.slideshow-container > div.mySlides > a > img

snippet: <img alt="Main Banner Image" src="/image/journal/article?img_id=488500349&t=1776690427734" style="width:100%;max-height:400px">

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

value: No additional origins are good candidates for preconnecting

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Transfer Size	Duration
www.googletagmanager.com/gtag/js?id=UA-189672-63&l=gDataLayer	125.2 KiB	518 ms
/html/js/barebone.jsp?browserId=other&themeId=cochrane_WA...	121.7 KiB	246 ms
/html/portlet/dynamic_data_mapping/js/main.js?browserId=o...	4.2 KiB
/html/portlet/dynamic_data_lists/js/main.js?browserId=oth...	4.2 KiB
/notifications-portlet/notifications/css/main.css?browser...	2.2 KiB
/cochrane-theme/css/custom.css?browserId=other&themeId=co...	93.4 KiB	328 ms
/html/portlet/dynamic_data_mapping/css/main.css?browserId...	1.2 KiB
fonts.googleapis.com/css?family=Source+Sans+Pro:400,700,600,900	1.3 KiB	269 ms
/html/css/main.css?browserId=other&themeId=cochrane_WAR_c...	20.2 KiB
/cochrane-theme/css/aui.css?browserId=other&themeId=cochr...	0 B
cmp.osano.com/AzZdRbSORDOOzF9W/d594efc1-9663-477d-9528-6576640e64fd/osano.js	63.9 KiB	416 ms
static.addtoany.com/menu/page.js	2.2 KiB	266 ms
/html/portlet/journal_content/css/main.css?browserId=othe...	473 B
/cochrane-theme/css/main.css?browserId=other&themeId=coch...	0 B
/html/portlet/login/css/main.css?browserId=other&themeId=...	495 B
/scolaris-content-display/css/main.css?browserId=other&th...	239 B
/cochrane-theme/css/main.css?browserId=other&themeId=coch...	0 B
/cochrane-theme/css/aui.css?browserId=other&themeId=cochr...	0 B

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

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: 120 ms 108.6 KiB

URL	Transfer Size	Est Savings
/cochrane-theme/css/custom.css?browserId=other&themeId=co...	93.3 KiB	88.5 KiB
/html/css/main.css?browserId=other&themeId=cochrane_WAR_c...	20.1 KiB	20.1 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: 250 ms 361.6 KiB

URL	Transfer Size	Est Savings
www.cochranelibrary.com/cochrane-theme/js/theme.js?t=1776315578000	174.0 KiB	113.3 KiB
www.googletagmanager.com/gtag/js?id=G-BRLBHKT9XF&l=gDataLayer&cx=c&gtm=4e64k0	144.7 KiB	69.1 KiB
/html/js/barebone.jsp?browserId=other&themeId=cochrane_WA...	121.6 KiB	68.0 KiB
www.googletagmanager.com/gtag/js?id=UA-189672-63&l=gDataLayer	124.9 KiB	63.9 KiB
assets.adobedtm.com/59640f9fa510/7cad07cf7779/launch-a215d9c51521.min.js	59.8 KiB	25.1 KiB
cmp.osano.com/AzZdRbSORDOOzF9W/d594efc1-9663-477d-9528-6576640e64fd/osano.js	63.4 KiB	22.2 KiB

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

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
Maternal, `article.mini-hero > a.mini-hero-module > div.mini-hero-image-wrapper > img.mini-hero-image`	www.cochranelibrary.com/image/journal/article?img_id=486670272&t=1774877752093
Multiple `article.mini-hero > a.mini-hero-module > div.mini-hero-image-wrapper > img.mini-hero-image`	www.cochranelibrary.com/image/journal/article?img_id=486670274&t=1774877752172
Infectious `article.mini-hero > a.mini-hero-module > div.mini-hero-image-wrapper > img.mini-hero-image`	www.cochranelibrary.com/image/journal/article?img_id=486670276&t=1774877752253
Climate `article.mini-hero > a.mini-hero-module > div.mini-hero-image-wrapper > img.mini-hero-image`	www.cochranelibrary.com/image/journal/article?img_id=486670278&t=1774877752328
Main Banner Image `div.slideshow-container > div.mySlides > a > img`	www.cochranelibrary.com/image/journal/article?img_id=488500349&t=1776690427734
Image 3 `div.journal-content-article > div.external-link-row > a > img`	www.cochranelibrary.com/cochrane-theme/images/external_links/our_journal.png
Image 2 `div.journal-content-article > div.external-link-row > a > img`	www.cochranelibrary.com/cochrane-theme/images/external_links/our_evidence.png
Image 4 `div.journal-content-article > div.external-link-row > a > img`	www.cochranelibrary.com/cochrane-theme/images/external_links/how_to_order.png
Image 5 `div.journal-content-article > div.external-link-row > a > img`	www.cochranelibrary.com/cochrane-theme/images/external_links/our_products.png
Image 1 `div.journal-content-article > div.external-link-row > a > img`	www.cochranelibrary.com/cochrane-theme/images/external_links/get_involved.png
Cochrane Library logo `div.branding > h1.brand-container > a > img.brand-logo`	www.cochranelibrary.com/cochrane-theme/images/en-US_logo.png
Stay connected with us `article.alert-content-module > div.button-container > div.alert-module-image-wrapper > img`	www.cochranelibrary.com/cochrane-theme/images/social/bell.png
div.brand-content > div.logo-block > a > img.footer-logo `div.brand-content > div.logo-block > a > img.footer-logo`	www.cochranelibrary.com/cochrane-theme/images/footer-logo-part-2.png
Wiley logo `div.brand > div.brand-container > a > img.logo`	www.cochranelibrary.com/cochrane-theme/images/en-US_wiley-footer-logo.png
Cochrane logo `div.brand-content > div.logo-block > a > img.footer-logo`	www.cochranelibrary.com/cochrane-theme/images/footer-logo-part-1.png
article.alert-content-module > div.button-container > a.alert-button > img `article.alert-content-module > div.button-container > a.alert-button > img`	www.cochranelibrary.com/cochrane-theme/images/social/bluesky-sm.svg

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

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: 677 ms

URL	Time Spent
cochranelibrary.com/	383 ms
www.cochranelibrary.com/	253 ms
www.cochranelibrary.com/?cookiesEnabled	41 ms
www.cochranelibrary.com/	0.0 ms

These are the largest layout shifts observed on the page. Each table item represents a single layout shift, and shows the element that shifted the most. Below each item are possible root causes that led to the layout shift. Some of these layout shifts may not be included in the CLS metric value due to windowing. Learn how to improve CLS

Why this matters

Performance issues directly impact user engagement and conversion rates.

Element	Layout shift score
Topics Blood and immune system conditions Cancer Cardiovascular conditions Cell… `div.site-container > div#content > div#main-content > div.container`	0.346
Basic Search Title Abstract Keyword Browse Advanced search `div.site-container > header > div.container > div.desktop-search`	0.001

●Time to Interactive 2.0 s

●Optimize DOM size

●LCP breakdown

●Modern HTTP

●Optimize viewport for mobile

●Max Potential First Input Delay 50 ms

●Minify CSS

●Minify JavaScript

●Avoids enormous network payloads Total size was 1,903 KiB

●JavaScript execution time 0.5 s

●Minimizes main-thread work 1.2 s

●Avoid non-composited animations 2 animated elements found

●Network Requests

●Network Round Trip Times 30 ms

●Server Backend Latencies 140 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Initial server response time was short Root document took 260 ms

○INP breakdown

○User Timing marks and measures

○Avoid long main-thread tasks

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
Stay connected with us `article.alert-content-module > div.button-container > div.alert-module-image-wrapper > h4`

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
article.alert-content-module > div.button-container > a.alert-button > img `article.alert-content-module > div.button-container > a.alert-button > img`

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.

○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

●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.

●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 are distinguishable without relying on color.

●Links have a discernible name

●Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).

●List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements

●No element has a `[tabindex]` value greater than 0

●Touch targets have sufficient size and spacing.

●Document has a main landmark.

●Deprecated ARIA roles were not used

●Identical links have the same purpose.

○`[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

○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

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

○`<object>` elements have alternate text

○Select elements have associated label elements.

○Skip links are focusable.

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

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

○`[lang]` attributes have a valid value

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

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

○All heading elements contain content.

○Uses ARIA roles only on compatible elements

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

○Elements with visible text labels have matching accessible names.

○Tables use `<caption>` instead of cells with the `[colspan]` attribute to indicate a caption.

○`<td>` elements in a large `<table>` have one or more table headers.

Best Practices

General

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Deprecation / Warning	Source
Unload event listeners are deprecated and will be removed.	cmp.osano.com/AzZdRbSORDOOzF9W/d594efc1-9663-477d-9528-6576640e64fd/osano.js line 1, col 141321
SharedStorage	www.cochranelibrary.com/cdn-cgi/challenge-platform/scripts/jsd/main.js
StorageType.persistent is deprecated. Please use standardized navigator.storage instead.	www.cochranelibrary.com/cdn-cgi/challenge-platform/scripts/jsd/main.js
Fledge	www.cochranelibrary.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
/scolaris-content-display/js/topics-lookup.js?browserId=o...	`Failed to load resource: the server responded with a status of 404 ()`
www.cochranelibrary.com/scolaris-browse-by-crg/icon.png	`Failed to load resource: the server responded with a status of 404 ()`
/cochrane-theme/js/main.js?browserId=other&minifierType=j...	`Failed to load resource: the server responded with a status of 404 ()`
www.cochranelibrary.com/	`Refused to apply style from 'https://www.cochranelibrary.com/cochrane-theme/css/aui.css?browserId=other&themeId=cochrane_WAR_cochranetheme&minifierType=css&languageId=en_US&b=6210&t=1776315578000' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled.`
www.cochranelibrary.com/	`Refused to apply style from 'https://www.cochranelibrary.com/cochrane-theme/css/aui.css?browserId=other&themeId=cochrane_WAR_cochranetheme&minifierType=css&languageId=en_US&b=6210&t=1776315578000' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled.`
www.cochranelibrary.com/	`Refused to apply style from 'https://www.cochranelibrary.com/cochrane-theme/css/main.css?browserId=other&themeId=cochrane_WAR_cochranetheme&minifierType=css&languageId=en_US&b=6210&t=1776315578000' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled.`
www.cochranelibrary.com/	`Refused to apply style from 'https://www.cochranelibrary.com/cochrane-theme/css/main.css?browserId=other&themeId=cochrane_WAR_cochranetheme&minifierType=css&languageId=en_US&b=6210&t=1776315578000' because its MIME type ('text/html') is not a supported stylesheet MIME type, and strict MIME checking is enabled.`
www.cochranelibrary.com/	`Refused to execute script from 'https://www.cochranelibrary.com/cochrane-theme/js/main.js?browserId=other&minifierType=js&languageId=en_US&b=6210&t=1776315578000' because its MIME type ('text/html') is not executable, and strict MIME type checking is enabled.`
www.cochranelibrary.com/	`Refused to execute script from 'https://www.cochranelibrary.com/scolaris-content-display/js/topics-lookup.js?browserId=other&minifierType=js&languageId=en_US&b=6210&t=1776315622000' because its MIME type ('text/html') is not executable, and strict MIME type checking is enabled.`

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Map URL
www.cochranelibrary.com/cochrane-theme/js/theme.js?t=1776315578000
cmp.osano.com/AzZdRbSORDOOzF9W/d594efc1-9663-477d-9528-6576640e64fd/osano.js	cmp.osano.com/AzZdRbSORDOOzF9W/d594efc1-9663-477d-9528-6576640e64fd/osano.js.map

●Uses HTTPS

●Avoids third-party cookies

●Allows users to paste into input fields

●Avoids requesting the geolocation permission on page load

●Avoids requesting the notification permission on page load

●Displays images with correct aspect ratio

●Serves images with appropriate resolution

●Page has the HTML doctype

●Properly defines charset

●No 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

○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.

Crawling and Indexing

Search engines may use `href` attributes on links to crawl websites. Ensure that the `href` attribute of anchor elements links to an appropriate destination, so more pages of the site can be discovered. Learn how to make links crawlable

Why this matters

Performance issues directly impact user engagement and conversion rates.

Uncrawlable Link
❮ `div.portlet-body > div.journal-content-article > div.slideshow-container > a.prev`
❯ `div.portlet-body > div.journal-content-article > div.slideshow-container > a.next`

To appear in search results, crawlers need access to your app.

Content Best Practices

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
article.alert-content-module > div.button-container > a.alert-button > img `article.alert-content-module > div.button-container > a.alert-button > img`

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 have descriptive text

●Document has a valid `hreflang`

●Document has a valid `rel=canonical`

○robots.txt is valid