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Lighthouse Mobile

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

Audit breakdown by category with detailed findings.

27

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
/fit-in/800x600/filters:format(webp)/prod01/prodbucket01/...1800.0 s203.3 KiB
/fit-in/800x600/filters:format(webp)/prod01/prodbucket01/...1800.0 s146.6 KiB
/fit-in/1280x720/filters:format(webp)/prod01/prodbucket01...1800.0 s121.3 KiB
cdn.curator.io/5.0/curator.embed.js0.0 ms103.1 KiB
/fit-in/1280x720/filters:format(webp)/prod01/prodbucket01...1800.0 s101.3 KiB
connect.facebook.net/en_US/fbevents.js1200.0 s96.6 KiB
/fit-in/1280x720/filters:format(webp)/prod01/prodbucket01...1800.0 s82.1 KiB
connect.facebook.net/en_GB/bundle/sdk.js/1200.0 s77.8 KiB
/fit-in/1280x720/filters:format(webp)/prod01/prodbucket01...1800.0 s61.7 KiB
/fit-in/800x450/filters:format(webp)/prod01/prodbucket01/...1800.0 s51.3 KiB
/fit-in/800x600/filters:format(webp)/prod01/channel_4/thi...1800.0 s50.3 KiB
/signals/config/442745680346526?v=2.9.303&r=stable&domain...1200.0 s44.8 KiB
/fit-in/800x450/filters:format(webp)/prod01/prodbucket01/...1800.0 s41.2 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s38.5 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s38.0 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s36.0 KiB
/fit-in/800x600/filters:format(webp)/prod01/channel_3/bus...1800.0 s35.0 KiB
/fit-in/800x450/filters:format(webp)/prod01/prodbucket01/...1800.0 s34.4 KiB
hit.uptrendsdata.com/rum.min.js3600.0 s36.8 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s31.9 KiB
/fit-in/800x450/filters:format(webp)/prod01/prodbucket01/...1800.0 s31.4 KiB
/media/durham-university/site-assets/css/durham-style-enh...604800.0 s261.4 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s30.2 KiB
dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js172800.0 s77.5 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s25.7 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s23.6 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s22.6 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s21.2 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s21.1 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s20.7 KiB
/fit-in/800x450/filters:format(webp)/prod01/prodbucket01/...1800.0 s19.7 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s19.4 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s19.4 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s19.3 KiB
www.google-analytics.com/analytics.js7200.0 s20.9 KiB
cdn.curator.io/5.0/curator.embed.css0.0 ms14.8 KiB
/signals/config/551711695170774?v=2.9.303&r=stable&domain...1200.0 s16.4 KiB
/signals/config/592550439717364?v=2.9.303&r=stable&domain...1200.0 s16.3 KiB
/signals/config/879205401832058?v=2.9.303&r=stable&domain...1200.0 s16.3 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s15.8 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s15.4 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s14.6 KiB
/fit-in/768x432/filters:format(webp)/prod01/prodbucket01/...1800.0 s13.5 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s13.2 KiB
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...1800.0 s13.1 KiB
scripts.clarity.ms/0.8.60-beta/clarity.js86400.0 s25.0 KiB
/fit-in/768x432/filters:format(webp)/prod01/prodbucket01/...1800.0 s11.5 KiB
/fit-in/768x432/filters:format(webp)/prod01/prodbucket01/...1800.0 s10.9 KiB
i.ytimg.com/vi_webp/3TOFwxddi94/sddefault.webp7200.0 s10.7 KiB
player.vimeo.com/api/player.js1800.0 s9.0 KiB
snap.licdn.com/li.lms-analytics/insight.min.js86400.0 s18.7 KiB
static.hotjar.com/c/hotjar-2581899.js?sv=760.0 s6.2 KiB
i3.ytimg.com/vi/3TOFwxddi94/hqdefault.jpg7200.0 s7.7 KiB
dur.ac.uk/media/durham-university/site-assets/image/logo-dark.svg172800.0 s16.6 KiB
dur.ac.uk/media/durham-university/site-assets/image/logo-white.svg172800.0 s16.6 KiB
/media/durham-university/site-assets/fonts/open-sans-v17-...172800.0 s15.0 KiB
/media/durham-university/site-assets/fonts/open-sans-v17-...172800.0 s14.9 KiB
connect.facebook.net/en_GB/sdk.js#xfbml=1&version=v7.01200.0 s5.0 KiB
/media/durham-university/site-assets/fonts/open-sans-v17-...172800.0 s14.8 KiB
connect.facebook.net/en_US/sdk.js1200.0 s5.0 KiB
/media/durham-university/site-assets/fonts/open-sans-v17-...172800.0 s14.3 KiB
/media/durham-university/site-assets/fonts/open-sans-v17-...172800.0 s13.8 KiB
dur.ac.uk/media/durham-university/site-assets/js/durham-app-enhanced.js172800.0 s6.2 KiB
cdn.curator.io/published/1ca8dc29-3a1c-42fc-b6ca-8da2569a41c5.js0.0 ms1.4 KiB
/collect?v=2&fmt=js&pid=8466%2C5651458&time=1776891714840...0.0 ms907 B
dur.ac.uk/media/durham-university/site-assets/js/emergency.js172800.0 s2.3 KiB
cdn.curator.io/published-css/1ca8dc29-3a1c-42fc-b6ca-8da2569a41c5.css0.0 ms458 B
static.doubleclick.net/instream/ad_status.js900.0 s495 B
dur.ac.uk/media/durham-university/site-assets/css/swiper.css604800.0 s3.6 KiB
insight.adsrvr.org/track/pxl/?adv=8hqrd76&ct=0:cdqfmcl&fmt=30.0 ms149 B
dur.ac.uk/media/durham-university/site-assets/css/perfect-scrollbar.css604800.0 s994 B
/tr/?id=442745680346526&ev=PageView&dl=https%3A%2F%2Fdur....0.0 ms19 B
/tr/?id=551711695170774&ev=PageView&dl=https%3A%2F%2Fdur....0.0 ms16 B
/tr/?id=592550439717364&ev=PageView&dl=https%3A%2F%2Fdur....0.0 ms16 B
/tr/?id=879205401832058&ev=PageView&dl=https%3A%2F%2Fdur....0.0 ms16 B
/media/durham-university/homepage/headers/QS-2026-Homepag...172800.0 s0 B

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.woff245 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:58.412 source:map[column:68550 line:1 type:source-location url:https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.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:58.412 source:map[column:69646 line:0 type:source-location url:https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js urlProvider:network]] map[reflowTime:7.972 source:map[column:10307 line:0 type:source-location url:https://dur.ac.uk/media/durham-university/site-assets/js/durham-app-enhanced.js urlProvider:network]] map[reflowTime:28.718 source:map[type:text value:[unattributed]]]]

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
Stephenson front of college beautiful spring day div.col-md-6 > div.card > div.card__image > img.embed-responsive-item
/fit-in/800x600/filters:format(webp)/prod01/prodbucket01/...202.4 KiB191.2 KiB
A group of students by a river in front of Durham Cathedral div.col-md-6 > div.card > div.card__image > img.embed-responsive-item
/fit-in/800x600/filters:format(webp)/prod01/prodbucket01/...145.8 KiB135.9 KiB
A group of four students smiling and chatting. div.col-lg-3 > div.card > div.card__image > img.embed-responsive-item
/fit-in/1280x720/filters:format(webp)/prod01/prodbucket01...120.5 KiB104.7 KiB
photo of students sitting in the cafe chatting. div.col-lg-3 > div.card > div.card__image > img.embed-responsive-item
/fit-in/1280x720/filters:format(webp)/prod01/prodbucket01...100.5 KiB85.6 KiB
Four students walking and chatting on campus div.col-lg-3 > div.card > div.card__image > img.embed-responsive-item
/fit-in/1280x720/filters:format(webp)/prod01/prodbucket01...81.3 KiB65.0 KiB
Student studying in Bill Bryson Library div.col-lg-3 > div.card > div.card__image > img.embed-responsive-item
/fit-in/1280x720/filters:format(webp)/prod01/prodbucket01...60.9 KiB53.3 KiB
Koi carp banners fluttering in wind div.col-md-6 > div.card > div.card__image > img.embed-responsive-item
/fit-in/800x600/filters:format(webp)/prod01/channel_4/thi...49.6 KiB42.5 KiB
Business students seated at curving desk div.col-md-6 > div.card > div.card__image > img.embed-responsive-item
/fit-in/800x600/filters:format(webp)/prod01/channel_3/bus...34.3 KiB23.3 KiB
A woman and a man hold a framed certificate and smile at the camera. The certif… li.horizontal-slider__item > div.card > div.card__image > img.embed-responsive-item
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...21.9 KiB13.8 KiB
A two-storey Star Home li.horizontal-slider__item > div.card > div.card__image > img.embed-responsive-item
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...20.5 KiB12.4 KiB
A mixed group of primary school children running in a circle in a playground wi… li.horizontal-slider__item > div.card > div.card__image > img.embed-responsive-item
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...20.4 KiB12.3 KiB
Young children writing in a classroom li.horizontal-slider__item > div.card > div.card__image > img.embed-responsive-item
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...18.7 KiB10.7 KiB
A graphic showing a human jaw bone held together by 3D surgical plates. li.horizontal-slider__item > div.card > div.card__image > img.embed-responsive-item
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...15.2 KiB7.1 KiB
Image of SbmA with its li.horizontal-slider__item > div.card > div.card__image > img.embed-responsive-item
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...13.9 KiB5.8 KiB
A simulated image of a spiral galaxy with a bright centre and spiral arms, set … li.horizontal-slider__item > div.card > div.card__image > img.embed-responsive-item
/fit-in/500x281/filters:format(webp)/prod01/prodbucket01/...12.4 KiB4.3 KiB

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
/media/durham-university/site-assets/css/durham-style-enh...261.4 KiB4.2 s
dur.ac.uk/media/durham-university/site-assets/css/perfect-scrollbar.css994 B
dur.ac.uk/media/durham-university/site-assets/css/swiper.css3.6 KiB

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

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

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: 330 ms 44.3 KiB
URLTransfer SizeEst Savings
/media/durham-university/site-assets/css/durham-style-enh...261.4 KiB44.3 KiB

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 1.8 s 273.0 KiB
URLTransfer SizeEst Savings
/media/durham-university/site-assets/css/durham-style-enh...261.1 KiB259.4 KiB
cdn.curator.io/5.0/curator.embed.css14.4 KiB13.7 KiB

Reduce unused JavaScript and defer loading scripts until they are required to decrease bytes consumed by network activity. Learn how to reduce unused JavaScript.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 5.1 s 908.4 KiB
URLTransfer SizeEst Savings
www.googletagmanager.com/gtag/js?id=G-HTQ6N1C1EK&cx=c&gtm=4e64k0173.4 KiB69.9 KiB
cdn.curator.io/5.0/curator.embed.js102.1 KiB64.0 KiB
www.googletagmanager.com/gtag/js?id=AW-465216367&cx=c&gtm=4e64k0143.5 KiB62.6 KiB
www.googletagmanager.com/gtag/js?id=AW-17497736984&cx=c&gtm=4e64k0143.5 KiB62.4 KiB
www.googletagmanager.com/gtag/js?id=AW-943473154&cx=c&gtm=4e64k0143.3 KiB62.0 KiB
www.googletagmanager.com/gtag/js?id=AW-958583275&cx=c&gtm=4e64k0143.5 KiB61.7 KiB
www.googletagmanager.com/gtag/js?id=DC-4743369&cx=c&gtm=4e64k0129.2 KiB61.2 KiB
www.googletagmanager.com/gtag/js?id=DC-4768938&cx=c&gtm=4e64k0129.2 KiB61.2 KiB
www.googletagmanager.com/gtag/js?id=DC-14248141&cx=c&gtm=4e64k0129.2 KiB61.1 KiB
www.googletagmanager.com/gtag/js?id=DC-13730620&cx=c&gtm=4e64k0131.7 KiB61.0 KiB
www.googletagmanager.com/gtag/js?id=GT-55XJ2CHX&cx=c&gtm=4e64k0129.2 KiB57.7 KiB
dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js77.2 KiB53.8 KiB
connect.facebook.net/en_GB/bundle/sdk.js/77.7 KiB53.8 KiB
www.googletagmanager.com/gtm.js?id=GTM-MD895GR189.2 KiB44.0 KiB
script.hotjar.com/modules.6a0f3932cb1341a35c18.js56.1 KiB37.5 KiB
connect.facebook.net/en_US/fbevents.js96.5 KiB34.4 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
Unattributable1.1 s37 ms0.0 ms
dur.ac.uk/761 ms13 ms3.8 ms
www.googletagmanager.com/gtm.js?id=GTM-MD895GR539 ms425 ms94 ms
www.googletagmanager.com/gtag/js?id=G-HTQ6N1C1EK&cx=c&gtm=4e64k0463 ms343 ms44 ms
dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js452 ms116 ms31 ms
www.googletagmanager.com/gtag/js?id=DC-14248141&cx=c&gtm=4e64k0327 ms269 ms58 ms
www.googletagmanager.com/gtag/js?id=AW-943473154&cx=c&gtm=4e64k0307 ms268 ms37 ms
www.googletagmanager.com/gtag/js?id=DC-13730620&cx=c&gtm=4e64k0254 ms188 ms65 ms
cdn.curator.io/5.0/curator.embed.js238 ms130 ms42 ms
code.jquery.com/jquery-3.5.1.min.js233 ms196 ms21 ms
www.googletagmanager.com/gtag/js?id=AW-17497736984&cx=c&gtm=4e64k0230 ms190 ms39 ms
www.googletagmanager.com/gtag/js?id=AW-958583275&cx=c&gtm=4e64k0221 ms192 ms28 ms
www.googletagmanager.com/gtag/js?id=AW-465216367&cx=c&gtm=4e64k0205 ms169 ms32 ms
scripts.clarity.ms/0.8.60-beta/clarity.js203 ms174 ms5.5 ms
www.googletagmanager.com/gtag/js?id=GT-55XJ2CHX&cx=c&gtm=4e64k0202 ms160 ms39 ms
/media/durham-university/site-assets/css/durham-style-enh...180 ms0.0 ms0.0 ms
www.googletagmanager.com/gtag/js?id=DC-4768938&cx=c&gtm=4e64k0155 ms123 ms31 ms
/signals/config/442745680346526?v=2.9.303&r=stable&domain...155 ms135 ms19 ms
www.googletagmanager.com/gtag/js?id=DC-4743369&cx=c&gtm=4e64k0151 ms125 ms25 ms
script.hotjar.com/modules.6a0f3932cb1341a35c18.js134 ms114 ms15 ms
hit.uptrendsdata.com/rum.min.js125 ms83 ms42 ms
connect.facebook.net/en_US/fbevents.js116 ms85 ms30 ms
connect.facebook.net/en_GB/bundle/sdk.js/116 ms94 ms22 ms
snap.licdn.com/li.lms-analytics/insight.min.js77 ms55 ms19 ms
dur.ac.uk/media/durham-university/site-assets/js/durham-app-enhanced.js64 ms28 ms2.6 ms
www.google-analytics.com/analytics.js63 ms54 ms3.5 ms
cdn.curator.io/published/1ca8dc29-3a1c-42fc-b6ca-8da2569a41c5.js59 ms54 ms0.5 ms
static.ads-twitter.com/uwt.js57 ms53 ms3.1 ms
/signals/config/879205401832058?v=2.9.303&r=stable&domain...51 ms39 ms10 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 Evaluation4.3 s
Other1.7 s
Script Parsing & Compilation792 ms
Style & Layout502 ms
Parse HTML & CSS234 ms
Garbage Collection148 ms
Rendering54 ms

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
/media/durham-university/homepage/headers/QS-2026-Homepag...11.9 MiB
dur.ac.uk/media/durham-university/homepage/student-blog/Amal-Shetty.png1.6 MiB
www.youtube.com/s/player/1bb6ee63/player_embed_es6.vflset/en_US/base.js436.0 KiB
/media/durham-university/site-assets/css/durham-style-enh...261.4 KiB
/fit-in/800x600/filters:format(webp)/prod01/prodbucket01/...203.3 KiB
www.googletagmanager.com/gtm.js?id=GTM-MD895GR189.5 KiB
/s/_/ytembeds/_/js/k=ytembeds.base.en_US.5f0apfZzpOA.2021...183.1 KiB
www.googletagmanager.com/gtag/js?id=G-HTQ6N1C1EK&cx=c&gtm=4e64k0173.5 KiB
/fit-in/800x600/filters:format(webp)/prod01/prodbucket01/...146.6 KiB
www.googletagmanager.com/gtag/js?id=AW-958583275&cx=c&gtm=4e64k0143.6 KiB

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

●Layout shift culprits
●Document request latency
●Optimize DOM size
●LCP breakdown
●Modern HTTP
●Optimize viewport for mobile
●Minify JavaScript
●User Timing marks and measures 166 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 100 ms
●Server Backend Latencies 180 ms
●Tasks
●Diagnostics
●Metrics
●Screenshot Thumbnails
●Final Screenshot
●Script Treemap Data
●Resources Summary
●Avoid multiple page redirects
●Initial server response time was short Root document took 140 ms
○INP breakdown
○LCP request discovery
○Avoid non-composited animations
○Avoid large layout shifts
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

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
body.body > img body.body > 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.

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
Trading name div.u-text-small > ul.u-list-reset > li.list-item > a.u-text-grey-400
Cookie notice div.u-text-small > ul.u-list-reset > li.list-item > a.u-text-grey-400
Privacy notices div.u-text-small > ul.u-list-reset > li.list-item > a.u-text-grey-400

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
●Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.
●`[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.
●`button`, `link`, and `menuitem` elements have accessible names
●ARIA attributes are used as specified for the element's role
●`[aria-hidden="true"]` elements do not contain focusable descendents
●Elements use only permitted ARIA attributes
●Background and foreground colors have a sufficient contrast ratio
●Document has a `<title>` element
●`<frame>` or `<iframe>` elements have a title
●`<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
●No element has a `[tabindex]` value greater than 0
●Heading elements appear in a sequentially-descending order
●Document has a main landmark.
●Deprecated ARIA roles were not used
●`<video>` elements contain a `<track>` element with `[kind="captions"]`
●Identical links have the same purpose.
○`[accesskey]` values are unique
○Elements with `role="dialog"` or `role="alertdialog"` have accessible names.
○ARIA input fields have accessible names
○ARIA `meter` elements have accessible names
○ARIA `progressbar` elements have accessible names
○`[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
○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
○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.
77

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 / WarningSource
AttributionReporting
snap.licdn.com/li.lms-analytics/insight.min.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.

SourceDescription
dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js
TypeError: YT.Player is not a constructor at Proxy.createYouTubePlayers (https://dur.ac.uk/media/durham-university/site-assets/js/durham-app-enhanced.js:1:799) at Proxy.init (https://dur.ac.uk/media/durham-university/site-assets/js/durham-app-enhanced.js:1:1208) at eval (eval at saferEval (https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js:1:2981), <anonymous>:3:54) at saferEval (https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js:1:3110) at Component.evaluateReturnExpression (https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js:1:28059) at new Component (https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js:1:22646) at Object.initializeComponent (https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js:1:31151) at https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js:1:30011 at https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js:1:30350 at NodeList.forEach (<anonymous>)
dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js
TypeError: YT.Player is not a constructor at Proxy.createYouTubePlayers (https://dur.ac.uk/media/durham-university/site-assets/js/durham-app-enhanced.js:1:799) at Proxy.init (https://dur.ac.uk/media/durham-university/site-assets/js/durham-app-enhanced.js:1:1208) at eval (eval at saferEval (https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js:1:2981), <anonymous>:3:54) at saferEval (https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js:1:3110) at Component.evaluateReturnExpression (https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js:1:28059) at new Component (https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js:1:22646) at Object.initializeComponent (https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js:1:31151) at https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js:1:30975 at https://dur.ac.uk/media/durham-university/site-assets/js/dependencies-20231018.js:1:30554 at Array.forEach (<anonymous>)
●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
●Page has valid source maps
○Redirects HTTP traffic to HTTPS
○Mitigate clickjacking with XFO or CSP
85

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

If your robots.txt file is malformed, crawlers may not be able to understand how you want your website to be crawled or indexed. Learn more about robots.txt.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Line #ContentError
49Disallow: search.durham.ac.uk/s/resources-global/css/funnelback.autocompletion-2.6.0.cssPattern should either be empty, start with "/" or "*"
50Disallow: search.durham.ac.uk/s/resources-global/thirdparty/typeahead-0.11.1/typeahead.bundle.min.jsPattern should either be empty, start with "/" or "*"
51Disallow: search.durham.ac.uk/s/resources-global/thirdparty/handlebars-4.1/handlebars.min.jsPattern should either be empty, start with "/" or "*"
52Disallow: search.durham.ac.uk/s/resources-global/js/funnelback.autocompletion-2.6.0.jsPattern should either be empty, start with "/" or "*"

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
body.body > img body.body > 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
●Links are crawlable
●Document has a valid `hreflang`
●Document has a valid `rel=canonical`

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