Skip to content
https://cambridgeenglish.org

Lighthouse Mobile

· 0 checks — Mobile Lighthouse audit -- Performance, Accessibility, Best Practices, and SEO category breakdown.
SCORE
0
GRADE
FIX
0
REVIEW
0
PASS
0
INFO
0

Detailed Report

Audit breakdown by category with detailed findings.

38

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
cdn-ukwest.onetrust.com/scripttemplates/202507.1.0/otBannerSdk.js86400.0 s119.9 KiB
i.ytimg.com/vi_webp/X2ZSRWKTUVA/sddefault.webp7200.0 s22.8 KiB
/logos/b1267e56-9bec-4ebe-a985-519ebdee1430/1d68d9f9-4078...86400.0 s41.7 KiB
cdn-ukwest.onetrust.com/scripttemplates/otSDKStub.js86400.0 s9.1 KiB
cse.google.com/cse.js?cx=015306828578951525741:c1yjx6kt0fa0.0 ms3.5 KiB
/consent/e481ef75-0b7a-49f5-91f3-f91f339f73a3/OtAutoBlock.js86400.0 s7.0 KiB
cdn-ukwest.onetrust.com/logos/static/powered_by_logo.svg86400.0 s2.5 KiB
www.google.com/cse/static/style/look/v6/default.css3000.0 s1.2 KiB
cdn-ukwest.onetrust.com/logos/static/ot_close.svg86400.0 s648 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.

URLEst Savings
fonts.gstatic.com/s/roboto/v48/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBHMdazQ.woff250 ms
/s/sourcesanspro/v23/6xKydSBYKcSV-LCoeQqfX1RYOo3ig4vwlxdu...45 ms
/s/sourcesanspro/v23/6xK3dSBYKcSV-LCoeQqfX1RYOo3qOK7lujVj...35 ms
/s/sourcesanspro/v23/6xKydSBYKcSV-LCoeQqfX1RYOo3i54rwlxdu...35 ms
fonts.gstatic.com/s/roboto/v48/KFO7CnqEu92Fr1ME7kSn66aGLdTylUAMa3yUBA.woff235 ms
/s/opensans/v44/memtYaGs126MiZpBA-UFUIcVXSCEkx2cmqvXlWqWu...35 ms
/s/opensans/v44/memvYaGs126MiZpBA-UvWbX2vVnXBbObj2OVTS-mu...35 ms

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:source label:Top function call valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]
items: [map[reflowTime:6.284 source:map[column:22766 line:7 type:source-location url:https://cdn-ukwest.onetrust.com/scripttemplates/202507.1.0/otBannerSdk.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:46.819 source:map[column:29825 line:4 type:source-location url:https://www.cambridgeenglish.org/assets/js/vendor/jquery/1.11.3/jquery-1.11.3.min.js urlProvider:network]] map[reflowTime:12.653 source:map[column:613 line:0 type:source-location url:https://www.cambridgeenglish.org/assets/js/init.js?v=2.3 urlProvider:network]] map[reflowTime:27.031 source:map[type:text value:[unattributed]]] map[reflowTime:0.415 source:map[column:31266 line:1 type:source-location url:https://www.cambridgeenglish.org/assets/js/vendor/jquery/1.11.3/jquery-1.11.3.min.js urlProvider:network]] map[reflowTime:0.307 source:map[column:22211 line:0 type:source-location url:https://www.cambridgeenglish.org/js/jquery.fancybox--modified.js urlProvider:network]] map[reflowTime:1.246 source:map[column:24862 line:3 type:source-location url:https://www.cambridgeenglish.org/assets/js/vendor/jquery/1.11.3/jquery-1.11.3.min.js urlProvider:network]] map[reflowTime:0.244 source:map[column:28964 line:3 type:source-location url:https://www.cambridgeenglish.org/assets/js/vendor/jquery/1.11.3/jquery-1.11.3.min.js urlProvider:network]] map[reflowTime:0.653 source:map[column:24497 line:3 type:source-location url:https://www.cambridgeenglish.org/assets/js/vendor/jquery/1.11.3/jquery-1.11.3.min.js urlProvider:network]] map[reflowTime:5.834 source:map[column:282346 line:6 type:source-location url:https://cdn-ukwest.onetrust.com/scripttemplates/202507.1.0/otBannerSdk.js urlProvider:network]] map[reflowTime:0.45 source:map[column:27723 line:6 type:source-location url:https://cdn-ukwest.onetrust.com/scripttemplates/202507.1.0/otBannerSdk.js urlProvider:network]] map[reflowTime:5.647 source:map[column:280 line:386 type:source-location url:https://www.google.com/cse/static/element/dc329f57de078f5d/cse_element__en.js?usqp=CAM%3D urlProvider:network]] map[reflowTime:0.116 source:map[column:168 line:312 type:source-location url:https://www.google.com/cse/static/element/dc329f57de078f5d/cse_element__en.js?usqp=CAM%3D 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.

URLResource SizeEst Savings
Two educators smiling outdoors, representing trusted teaching support div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/trust_english-trust_page_updates_journey.jpg310.5 KiB286.6 KiB
Cambridge sustainability logo over aerial view of green forest div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/promise-to-the-planet.jpg280.9 KiB257.0 KiB
Aerial view of University of Cambridge. div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/cambridge-history-and-heritage.jpg233.8 KiB209.9 KiB
Top UK children’s books collection. div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/courses-and-materials-for-learning-english.jpg175.7 KiB153.8 KiB
Banner with where your world grows text. div.drupal > div.hero > div.hero-image > img
www.cambridgeenglish.org/Images/ce-banner.jpg173.0 KiB148.1 KiB
Man and woman talking on a couch. div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/cambridge-customer-support.jpg153.9 KiB134.7 KiB
Woman with glasses in library. div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/world-shaped-by-research-and-insights.jpg106.5 KiB93.2 KiB
Girl with headphones using laptop. div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/girl-taking-online-exam.jpg99.3 KiB87.0 KiB
Responsive website design on devices. div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/digital-tools-for-better-learning.jpg88.8 KiB77.8 KiB
Students learning at desks in orange classroom. div.drupal > div.educators-container > div.educators-box > img
www.cambridgeenglish.org/Images/students-in-a-classroom.jpeg58.1 KiB30.3 KiB
Man with glasses holding book in classroom. div.drupal > div.educators-container > div.educators-box > img
www.cambridgeenglish.org/Images/man-holding-a-book-in-a-classroom.jpg47.3 KiB23.8 KiB
monash-university div.feature > div > div.logo-container > img
www.cambridgeenglish.org/Images/Monash-University-logo.jpg10.8 KiB8.4 KiB
div.drupal > div.hero > div.hero-image > img div.drupal > div.hero > div.hero-image > img
www.cambridgeenglish.org/Images/blue%20wave%20divider.jpg7.7 KiB7.4 KiB
mcgill-logo div.feature > div > div.logo-container > img
www.cambridgeenglish.org/Images/McGill-logo.jpg7.0 KiB5.4 KiB
kings-college-logo div.feature > div > div.logo-container > img
www.cambridgeenglish.org/Images/Kings-College-London-logo.jpg5.3 KiB4.1 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-4-IMG
nodeLabel: Banner with where your world grows text.
path: 6,HTML,2,BODY,5,FORM,5,MAIN,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,IMG
selector: div.drupal > div.hero > div.hero-image > img
snippet: <img src="/Images/ce-banner.jpg" alt="Banner with where your world grows text.">

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
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.cambridgeenglish.org/assets/js/vendor/jquery/1.11.3/jquery-1.11.3.min.js33.0 KiB603 ms
www.cambridgeenglish.org/assets/css/style.css?v=3.854.8 KiB1.8 s
www.cambridgeenglish.org/js/jwplayer.js25.1 KiB301 ms
fonts.googleapis.com/css?family=Source+Sans+Pro:300,400,400i,600,600i,7001.4 KiB835 ms
/consent/e481ef75-0b7a-49f5-91f3-f91f339f73a3/OtAutoBlock.js7.0 KiB811 ms
cdn-ukwest.onetrust.com/scripttemplates/otSDKStub.js9.1 KiB668 ms
www.cambridgeenglish.org/assets/js/vendor/Site24x7/RUM1monitoring.js588 B
www.cambridgeenglish.org/assets/js/vendor/modernizr/modernizr.custom.min.js3.9 KiB151 ms
www.cambridgeenglish.org/css/local-business.css?v=2.815.4 KiB301 ms
www.cambridgeenglish.org/css/local-publication.css?v=2.521.0 KiB452 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

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: 845 ms
URLTime Spent
cambridgeenglish.org/845 ms
www.cambridgeenglish.org/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: 620 ms 119.6 KiB
URLTransfer SizeEst Savings
www.cambridgeenglish.org/assets/css/style.css?v=3.854.7 KiB53.2 KiB
www.cambridgeenglish.org/css/local-publication.css?v=2.520.9 KiB19.9 KiB
22.4 KiB19.8 KiB
www.cambridgeenglish.org/css/local-business.css?v=2.815.3 KiB14.8 KiB
www.google.com/cse/static/element/dc329f57de078f5d/default_v6+en.css11.9 KiB11.9 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: 4.2 s 606.3 KiB
URLTransfer SizeEst Savings
www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js361.8 KiB241.8 KiB
www.googletagmanager.com/gtm.js?id=GTM-NHCSV7173.2 KiB76.9 KiB
www.googletagmanager.com/gtag/js?id=G-RWH1WT5Q9J&cx=c&gtm=4e64k0h1171.0 KiB63.5 KiB
cdn-ukwest.onetrust.com/scripttemplates/202507.1.0/otBannerSdk.js119.8 KiB62.8 KiB
/assets/js/vendor/jquery-ui/1.11.4/jquery-ui.min.js?v=0.163.1 KiB56.7 KiB
/cse/static/element/dc329f57de078f5d/cse_element__en.js?u...102.7 KiB52.4 KiB
cse.google.com/adsense/search/async-ads.js43.3 KiB31.5 KiB
www.cambridgeenglish.org/js/jwplayer.js25.0 KiB20.7 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.

URLTotal CPU TimeScript EvaluationScript Parse
Unattributable644 ms86 ms0.0 ms
www.googletagmanager.com/gtm.js?id=GTM-NHCSV7518 ms412 ms55 ms
cdn-ukwest.onetrust.com/scripttemplates/202507.1.0/otBannerSdk.js464 ms343 ms54 ms
www.googletagmanager.com/gtag/js?id=G-RWH1WT5Q9J&cx=c&gtm=4e64k0h1368 ms314 ms51 ms
www.cambridgeenglish.org/331 ms28 ms8.4 ms
/assets/js/vendor/jquery-ui/1.11.4/jquery-ui.min.js?v=0.1261 ms52 ms22 ms
www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js212 ms110 ms101 ms
www.cambridgeenglish.org/assets/js/vendor/jquery/1.11.3/jquery-1.11.3.min.js199 ms156 ms11 ms
cse.google.com/cse.js?cx=015306828578951525741:c1yjx6kt0fa141 ms116 ms0.8 ms
www.cambridgeenglish.org/assets/js/init.js?v=2.399 ms48 ms2.2 ms
/cse/static/element/dc329f57de078f5d/cse_element__en.js?u...69 ms27 ms40 ms
/consent/e481ef75-0b7a-49f5-91f3-f91f339f73a3/OtAutoBlock.js66 ms51 ms4.8 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.

CategoryTime Spent
Script Evaluation1.9 s
Other657 ms
Style & Layout485 ms
Script Parsing & Compilation419 ms
Parse HTML & CSS154 ms
Garbage Collection37 ms
Rendering22 ms

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 10.0 KiB
URLTransfer SizeEst Savings
www.cambridgeenglish.org/css/local-business.css?v=2.815.4 KiB3.8 KiB
www.google.com/cse/static/element/dc329f57de078f5d/default_v6+en.css12.0 KiB3.3 KiB
www.cambridgeenglish.org/assets/css/print.css?v=0.43.9 KiB2.9 KiB

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.

URLTransfer Size
www.youtube-nocookie.com/s/player/1bb6ee63/player_embed.vflset/en_US/base.js471.9 KiB
www.gstatic.com/recaptcha/releases/gTpTIWhbKpxADzTzkcabhXN4/recaptcha__en.js362.4 KiB
www.cambridgeenglish.org/Images/trust_english-trust_page_updates_journey.jpg312.0 KiB
www.cambridgeenglish.org/Images/promise-to-the-planet.jpg282.3 KiB
www.cambridgeenglish.org/Images/cambridge-history-and-heritage.jpg235.0 KiB
/s/_/ytembeds/_/js/k=ytembeds.base.en_US.-RE1iC8VNhI.es5....202.7 KiB
www.cambridgeenglish.org/Images/courses-and-materials-for-learning-english.jpg176.6 KiB
www.cambridgeenglish.org/Images/ce-banner.jpg173.9 KiB
www.googletagmanager.com/gtm.js?id=GTM-NHCSV7173.8 KiB
www.googletagmanager.com/gtag/js?id=G-RWH1WT5Q9J&cx=c&gtm=4e64k0h1171.0 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
Woman with glasses in library. div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/world-shaped-by-research-and-insights.jpg
Top UK children’s books collection. div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/courses-and-materials-for-learning-english.jpg
Girl with headphones using laptop. div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/girl-taking-online-exam.jpg
Responsive website design on devices. div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/digital-tools-for-better-learning.jpg
Cambridge sustainability logo over aerial view of green forest div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/promise-to-the-planet.jpg
Aerial view of University of Cambridge. div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/cambridge-history-and-heritage.jpg
Man and woman talking on a couch. div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/cambridge-customer-support.jpg
Two educators smiling outdoors, representing trusted teaching support div.panel > div.panel__body > figure.article__media > img
www.cambridgeenglish.org/Images/trust_english-trust_page_updates_journey.jpg
monash-university div.feature > div > div.logo-container > img
www.cambridgeenglish.org/Images/Monash-University-logo.jpg
mcgill-logo div.feature > div > div.logo-container > img
www.cambridgeenglish.org/Images/McGill-logo.jpg
accenture-logo div.feature > div > div.logo-container > img
www.cambridgeenglish.org/Images/Accenture-logo.jpg
p+g-logo div.feature > div > div.logo-container > img.center-logo
www.cambridgeenglish.org/Images/P-and-G-logo.jpg
kings-college-logo div.feature > div > div.logo-container > img
www.cambridgeenglish.org/Images/Kings-College-London-logo.jpg
Cambridge University Press & Assessment ul.footer_container__list > li.footer_container__list-item > a.link--external > img.image--small
/Images/Cambridge_Press_Assessment_Landscape_Logo_RGB-280...
BSI Logo ul.footer_container__list > li.footer_container__list-item > a.link--external > img.image--small
www.cambridgeenglish.org/Images/bsi-logo-footer.png
ALTE logo ul.footer_container__list > li.footer_container__list-item > a.link--external > img.image--small
www.cambridgeenglish.org/Images/alte-logo-footer.png
English Profile logo ul.footer_container__list > li.footer_container__list-item > a.link--external > img.image--small
www.cambridgeenglish.org/Images/english-profile-logo-footer.png

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

●Layout shift culprits
●Optimize DOM size
●LCP breakdown
●Modern HTTP
●Optimize viewport for mobile
●Minify JavaScript
●User Timing marks and measures 9 user timings
●Avoid long main-thread tasks 15 long tasks found
●Avoid non-composited animations 1 animated element found
●Page didn't prevent back/forward cache restoration
●Network Requests
●Network Round Trip Times 60 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 30 ms
●Avoid large layout shifts 1 layout shift found
○INP breakdown
92

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.

Names and labels

When a button doesn't have an accessible name, screen readers announce it as "button", making it unusable for users who rely on screen readers. Learn how to make buttons more accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
header.header > div.header_wrap > div.js-header_controls > button#js-header_controls-search-id header.header > div.header_wrap > div.js-header_controls > button#js-header_controls-search-id
header.header > div.header_wrap > div.js-header_controls > button#js-header_controls-nav-id header.header > div.header_wrap > div.js-header_controls > button#js-header_controls-nav-id

Screen reader users rely on frame titles to describe the contents of frames. Learn more about frame titles.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
main#anchor-main > div > div > iframe main#anchor-main > div > div > iframe

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.

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
Cookie notice div#onetrust-group-container > div#onetrust-policy > div#onetrust-policy-text > a.ot-cookie-policy-link
○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
●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
●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.
●Heading elements appear in a sequentially-descending order
●Skip links are focusable.
●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
○`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.
○Input buttons have discernible text.
○`<input type="image">` elements have `[alt]` text
○Form elements have associated labels
○The document does not use `<meta http-equiv="refresh">`
○`<object>` elements have alternate text
○Select elements have associated label elements.
○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.
○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
www.cambridgeenglish.org/assets/js/init.js?v=2.3
TypeError: Cannot set properties of undefined (setting 'onclick') at https://www.cambridgeenglish.org/assets/js/init.js?v=2.3:1:23552
●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.cambridge.org/legal/cookiesMore information

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`

Send Feedback