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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.

22

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
hku.hk/f/frontpage/29052/3840c2160/260119_THE_Subject_Ranking_2026-07.jpg0.0 ms4.5 MiB
hku.hk/f/frontpage/29052/3840c2160/260119_THE_Subject_Ranking_2026-08.jpg0.0 ms4.1 MiB
hku.hk/f/frontpage/29052/3840c2160/SGP%20Inaugural%20Week%201.png0.0 ms4.1 MiB
/f/photo/29049/864p0/TeachingAndLearning2_Training Guardi...0.0 ms1.8 MiB
hku.hk/f/poster/28940/527p0/30thHKMF1000x1382@1054.png0.0 ms1.4 MiB
/f/photo/29009/864p0/KnowledgeExchange3_Safe to Swallow_h...0.0 ms1.4 MiB
hku.hk/f/flipboard/21473/1054c690/flipboard-events.jpg0.0 ms1.3 MiB
hku.hk/f/frontpage/29052/3840c2160/260318_Website_3_Banner_CurrentV_3_EN.jpg0.0 ms1.0 MiB
hku.hk/f/flipboard/21501/1054c690/career.JPG0.0 ms1023.7 KiB
hku.hk/f/flipboard/21472/1054c690/flipboard-libraries.jpg0.0 ms996.5 KiB
hku.hk/f/flipboard/7633/1054c690/GivingtoHKU2022_updated.PNG0.0 ms939.1 KiB
hku.hk/f/flipboard/21471/1054c690/ProspectiveStudents.JPG0.0 ms927.5 KiB
/f/photo/29049/864p0/TeachingAndLearning2_Training Guardi...0.0 ms873.4 KiB
hku.hk/f/frontpage/29052/1648c1112/221018_AdmissionOnHKUHomeBanner_4.jpeg0.0 ms863.2 KiB
hku.hk/f/photo/29009/864p0/KnowledgeExchange3_Safe%20to%20Swallow_hero%202.jpg0.0 ms831.0 KiB
hku.hk/f/flipboard/21483/1054c690/PubDec2025.png0.0 ms814.1 KiB
hku.hk/f/flipboard/7740/1054c690/IMG_5829a.jpg0.0 ms790.0 KiB
hku.hk/f/flipboard/21470/1054c690/currentstudent.JPG0.0 ms785.0 KiB
hku.hk/f/frontpage/29052/1920c654/HKU_Miansite_Desktop_Fculties_Banner_Law.jpg0.0 ms721.2 KiB
hku.hk/f/poster/28842/527p0/HKUbannerRoll@1054.jpg0.0 ms696.3 KiB
hku.hk/f/flipboard/21504/1054c690/flipboard-hkuinthemedia.jpg0.0 ms644.9 KiB
hku.hk/f/flipboard/7738/1054c690/tnl2024.jpg0.0 ms635.3 KiB
hku.hk/f/flipboard/10567/1054c690/publicity.jpg0.0 ms599.3 KiB
hku.hk/f/poster/28940/527p0/30thHKMF1000x1382.png0.0 ms575.5 KiB
hku.hk/f/photo/29010/864p0/Research5_Does%20AI%20Have%20a%20Mind@1728.jpg0.0 ms499.5 KiB
hku.hk/f/frontpage/29052/3840c2160/QS-Asia-University-Ranking-2026.jpg0.0 ms483.9 KiB
hku.hk/f/photo/29050/864p0/CoverStory4_A-Better-Way-to-Share@1728.jpg0.0 ms479.6 KiB
hku.hk/f/poster/28842/527p0/HKUbannerRoll.jpg0.0 ms438.2 KiB
hku.hk/f/poster/28943/527p0/mahkcs-in-hku-website-1000x1382@1054.jpg0.0 ms394.3 KiB
hku.hk/f/poster/28943/527p0/mahkcs-in-hku-website-1000x1382.jpg0.0 ms389.1 KiB
hku.hk/f/flipboard/7916/1054c690/flipboard-multimedia.jpg0.0 ms386.2 KiB
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-3.jpg0.0 ms385.6 KiB
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-2.jpg0.0 ms362.8 KiB
hku.hk/assets/js/index.js?t=202304140.0 ms355.3 KiB
hku.hk/f/frontpage/29052/3840c2160/251104_HKU-Highly-Cited-Research_banner.jpg0.0 ms334.4 KiB
hku.hk/assets/css/index.css?t=202304140.0 ms320.3 KiB
hku.hk/f/photo/29050/864p0/CoverStory4_A-Better-Way-to-Share.jpg0.0 ms301.0 KiB
hku.hk/f/flipboard/7739/1054c690/Research_2x_1054x694.jpg0.0 ms300.7 KiB
hku.hk/f/photo/29010/864p0/Research5_Does%20AI%20Have%20a%20Mind.jpg0.0 ms261.2 KiB
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-8.jpg0.0 ms220.8 KiB
hku.hk/f/banner/331/258c90/uv_banner_350x123.gif0.0 ms207.6 KiB
hku.hk/f/banner/331/258c90/uv_banner_350x123@750.gif0.0 ms207.6 KiB
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-9.jpg0.0 ms169.4 KiB
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-5.jpg0.0 ms143.5 KiB
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-4.jpg0.0 ms137.2 KiB
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-10.jpg0.0 ms133.0 KiB
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-1.jpg0.0 ms115.4 KiB
hku.hk/assets/img/hku-115.svg?t=17609501440.0 ms92.9 KiB
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-6.jpg0.0 ms92.4 KiB
hku.hk/f/banner/28939/258c90/30th%20HKMF_W350xH123@750.png0.0 ms85.0 KiB
hku.hk/assets/min/js/mobile_menu.js?t=202304140.0 ms69.3 KiB
hku.hk/assets/fonts/roboto-medium-webfont.woff20.0 ms65.9 KiB
hku.hk/assets/fonts/roboto-regular-webfont.woff20.0 ms65.0 KiB
hku.hk/assets/img/home/img_bhv-bg-default.jpg?15987027240.0 ms60.6 KiB
hku.hk/f/banner/28843/258c90/HKUsmallBanner@750.jpg0.0 ms60.0 KiB
/f/banner/29062/258c90/For HKU Web banner 350 x 123 px@75...0.0 ms59.2 KiB
hku.hk/f/banner/28939/258c90/30th%20HKMF_W350xH123.png0.0 ms44.4 KiB
hku.hk/assets/js/main.min.js?t=202304140.0 ms42.5 KiB
hku.hk/f/banner/28843/258c90/HKUsmallBanner.jpg0.0 ms40.6 KiB
hku.hk/f/banner/14717/258c90/bannerSPACE@750.jpg0.0 ms38.9 KiB
hku.hk/f/banner/29062/258c90/For%20HKU%20Web%20banner%20350%20x%20123%20px.png0.0 ms36.7 KiB
hku.hk/assets/fonts/frankruhllibre-black-webfont.woff20.0 ms36.4 KiB
hku.hk/assets/img/besthk-logo-2016.png?t=201705110.0 ms35.1 KiB
hku.hk/assets/min/js/menu.js?t=202304140.0 ms34.7 KiB
hku.hk/f/banner/28942/258c90/mahkcs-hku-banner-350x123px@750.gif0.0 ms26.3 KiB
hku.hk/assets/fonts/frankruhllibre-bold-webfont.woff20.0 ms24.3 KiB
hku.hk/assets/fonts/frankruhllibre-medium-webfont.woff20.0 ms23.7 KiB
hku.hk/f/banner/27503/258c90/Untitled%20design.jpg0.0 ms23.4 KiB
hku.hk/f/banner/14717/258c90/bannerSPACE.jpg0.0 ms21.8 KiB
hku.hk/assets/js/slide/banner.js?t=202304140.0 ms18.1 KiB
hku.hk/assets/img/2014_Standard_Winner.png?t=201609210.0 ms16.7 KiB
ssl.google-analytics.com/ga.js7200.0 s17.4 KiB
hku.hk/f/banner/27503/258c90/Untitled%20design@750.jpg0.0 ms11.4 KiB
hku.hk/assets/img/cad-27th.png?t=202106280.0 ms6.9 KiB
hku.hk/assets/img/WARS-Triple-Gold-hku-color.png?t=202309010.0 ms6.5 KiB
static.hotjar.com/c/hotjar-1966860.js?sv=760.0 s6.2 KiB
hku.hk/assets/img/menu/icon_knowledge-exchange.png0.0 ms6.0 KiB
hku.hk/assets/img/menu/icon_teaching-and-learning.png0.0 ms5.7 KiB
hku.hk/assets/min/js/json_data.js?t=202304140.0 ms5.6 KiB
hku.hk/assets/img/menu/icon_libraries.png0.0 ms5.4 KiB
hku.hk/assets/img/menu/icon_current.png0.0 ms5.1 KiB
hku.hk/assets/img/menu/icon_prospective-students.png0.0 ms5.0 KiB
hku.hk/assets/fonts/icomoon/fonts/wico.woff20.0 ms4.9 KiB
hku.hk/assets/img/menu/icon_giving.png0.0 ms4.8 KiB
hku.hk/assets/img/lib_slick/ajax-loader.gif0.0 ms4.7 KiB
hku.hk/assets/img/menu/icon_media.png0.0 ms4.6 KiB
hku.hk/assets/img/menu/icon_research.png0.0 ms4.6 KiB
hku.hk/assets/img/menu/icon_alumni.png0.0 ms4.2 KiB
hku.hk/assets/img/menu/icon_about-hku.png0.0 ms3.9 KiB
hku.hk/assets/js/device.min.js?t=202304140.0 ms3.9 KiB
hku.hk/assets/img/menu/icon_staff.png0.0 ms3.9 KiB
hku.hk/assets/img/menu/icon_events.png0.0 ms3.2 KiB
hku.hk/assets/img/menu/icon_hku-portal.png0.0 ms3.1 KiB
hku.hk/assets/img/menu/icon_visitor.png0.0 ms3.1 KiB
hku.hk/assets/img/menu/icon_faculties-and-departments.png0.0 ms2.9 KiB
hku.hk/assets/css/print.css0.0 ms2.0 KiB
hku.hk/assets/js/high-contrast.js?t=202304140.0 ms1.9 KiB
hku.hk/assets/img/menu/icon_publications-new.png?t=16261409381020.0 ms1.5 KiB
hku.hk/assets/img/svg/icon_android.svg0.0 ms1.4 KiB
hku.hk/assets/img/svg/icon_ios.svg0.0 ms1.4 KiB
hku.hk/assets/img/menu/icon_careers.png?t=16261409381020.0 ms1.4 KiB
hku.hk/assets/img/svg/icon_more.svg0.0 ms1.2 KiB
hku.hk/assets/img/svg/icon_fb.svg0.0 ms1.1 KiB

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:9.2e-05] map[node:map[boundingRect:map[bottom:38 height:13 left:337 right:392 top:25 width:55] lhId:page-36-DIV nodeLabel:中 Toggle menu panel path:4,HTML,1,BODY,6,DIV,2,DIV,0,DIV,0,DIV,1,DIV selector:div.page-head > div.container-wide > div.page-head__inner > div.page-head__inner-right snippet:<div class="page-head__inner-right"> type:node] score:6e-05 subItems:map[items:[map[cause:Web font extra:map[type:url value:https://hku.hk/assets/fonts/roboto-regular-webfont.woff2]] map[cause:Web font extra:map[type:url value:https://hku.hk/assets/fonts/roboto-medium-webfont.woff2]] map[cause:Web font extra:map[type:url value:https://hku.hk/assets/fonts/frankruhllibre-medium-webfont.woff2]]] type:subitems]] map[node:map[boundingRect:map[bottom:38 height:13 left:337 right:392 top:25 width:55] lhId:page-36-DIV nodeLabel:中 Toggle menu panel path:4,HTML,1,BODY,6,DIV,2,DIV,0,DIV,0,DIV,1,DIV selector:div.page-head > div.container-wide > div.page-head__inner > div.page-head__inner-right snippet:<div class="page-head__inner-right"> type:node] score:3.2e-05 subItems:map[items:[map[cause:Web font extra:map[type:url value:https://hku.hk/assets/fonts/icomoon/fonts/wico.woff2]]] type:subitems]]]
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:0.26633300000000004] map[node:map[boundingRect:map[bottom:1334 height:496 left:0 right:412 top:837 width:412] lhId:page-37-DIV nodeLabel:Teaching & Learning News Centre Previous Next HKU in the Media Prospective Stud… path:4,HTML,1,BODY,6,DIV,4,DIV,0,DIV,1,MAIN,1,DIV,1,DIV selector:div.content-container > main.page-content > div#main > div.flipboard snippet:<div class="flipboard"> type:node] score:0.264842] map[node:map[boundingRect:map[bottom:1334 height:496 left:0 right:412 top:837 width:412] lhId:page-37-DIV nodeLabel:Teaching & Learning News Centre Previous Next HKU in the Media Prospective Stud… path:4,HTML,1,BODY,6,DIV,4,DIV,0,DIV,1,MAIN,1,DIV,1,DIV selector:div.content-container > main.page-content > div#main > div.flipboard snippet:<div class="flipboard"> type:node] score:0.001454] map[node:map[boundingRect:map[bottom:38 height:13 left:337 right:392 top:25 width:55] lhId:page-36-DIV nodeLabel:中 Toggle menu panel path:4,HTML,1,BODY,6,DIV,2,DIV,0,DIV,0,DIV,1,DIV selector:div.page-head > div.container-wide > div.page-head__inner > div.page-head__inner-right snippet:<div class="page-head__inner-right"> type:node] score:3.7e-05]]

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
hku.hk/assets/fonts/roboto-medium-webfont.woff2745 ms
hku.hk/assets/fonts/roboto-regular-webfont.woff2740 ms
hku.hk/assets/fonts/frankruhllibre-bold-webfont.woff2515 ms
hku.hk/assets/fonts/frankruhllibre-medium-webfont.woff2485 ms
hku.hk/assets/fonts/frankruhllibre-black-webfont.woff2245 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:71.602 source:map[column:30300 line:2 type:source-location url:https://hku.hk/assets/js/index.js?t=20230414 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:54.383 source:map[column:51844 line:1 type:source-location url:https://hku.hk/assets/js/index.js?t=20230414 urlProvider:network]] map[reflowTime:1.841 source:map[column:87016 line:1 type:source-location url:https://hku.hk/assets/js/index.js?t=20230414 urlProvider:network]] map[reflowTime:6.319 source:map[column:85979 line:1 type:source-location url:https://hku.hk/assets/js/index.js?t=20230414 urlProvider:network]] map[reflowTime:5.164 source:map[column:51866 line:1 type:source-location url:https://hku.hk/assets/js/index.js?t=20230414 urlProvider:network]] map[reflowTime:0.348 source:map[column:87079 line:1 type:source-location url:https://hku.hk/assets/js/index.js?t=20230414 urlProvider:network]] map[reflowTime:3.584 source:map[column:13396 line:78 type:source-location url:https://hku.hk/assets/js/index.js?t=20230414 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
div.slider__item > a > div.placeholder > img.placeholder__item div.slider__item > a > div.placeholder > img.placeholder__item
hku.hk/f/frontpage/29052/3840c2160/260119_THE_Subject_Ranking_2026-07.jpg4.5 MiB4.5 MiB
div.slider__item > a > div.placeholder > img.placeholder__item div.slider__item > a > div.placeholder > img.placeholder__item
hku.hk/f/frontpage/29052/3840c2160/260119_THE_Subject_Ranking_2026-08.jpg4.1 MiB4.1 MiB
div.slider__item > a > div.placeholder > img.placeholder__item div.slider__item > a > div.placeholder > img.placeholder__item
hku.hk/f/frontpage/29052/3840c2160/SGP%20Inaugural%20Week%201.png4.1 MiB4.0 MiB
Building conservation careers while saving historical sites div.caphoto__item > a.caphoto__img-w > div.caphoto__img-c > img.caphoto__img
/f/photo/29049/864p0/TeachingAndLearning2_Training Guardi...1.8 MiB1.8 MiB
30th Hong Kong Medical Forum div.slick-track > a.flippy__inner > div.flippy__img-w > img.flippy__poster
hku.hk/f/poster/28940/527p0/30thHKMF1000x1382@1054.png1.4 MiB1.4 MiB
Restoring health and quality of life through safe swallowing innovations div.caphoto__item > a.caphoto__img-w > div.caphoto__img-c > img.caphoto__img
/f/photo/29009/864p0/KnowledgeExchange3_Safe to Swallow_h...1.4 MiB1.3 MiB
Events div.flippy > a.flippy__inner > div.flippy__img-w > img.placeholder__item
hku.hk/f/flipboard/21473/1054c690/flipboard-events.jpg1.3 MiB1.2 MiB
Careers div.flippy > a.flippy__inner > div.flippy__img-w > img.placeholder__item
hku.hk/f/flipboard/21501/1054c690/career.JPG1023.0 KiB1012.3 KiB
div.slider__item > a > div.placeholder > img.placeholder__item div.slider__item > a > div.placeholder > img.placeholder__item
hku.hk/f/frontpage/29052/3840c2160/260318_Website_3_Banner_CurrentV_3_EN.jpg1.0 MiB1005.3 KiB
Libraries div.flippy > a.flippy__inner > div.flippy__img-w > img.placeholder__item
hku.hk/f/flipboard/21472/1054c690/flipboard-libraries.jpg995.8 KiB985.1 KiB
Giving to HKU div.flippy > a.flippy__inner > div.flippy__img-w > img.placeholder__item
hku.hk/f/flipboard/7633/1054c690/GivingtoHKU2022_updated.PNG938.4 KiB927.7 KiB
Prospective Students div.flippy > a.flippy__inner > div.flippy__img-w > img.placeholder__item
hku.hk/f/flipboard/21471/1054c690/ProspectiveStudents.JPG926.9 KiB916.2 KiB
div.section-adm__pic > div.section-adm__img-w > div.placeholder > img.placeholder__item div.section-adm__pic > div.section-adm__img-w > div.placeholder > img.placeholder__item
hku.hk/f/frontpage/29052/1648c1112/221018_AdmissionOnHKUHomeBanner_4.jpeg862.6 KiB815.0 KiB
Publications div.flippy > a.flippy__inner > div.flippy__img-w > img.placeholder__item
hku.hk/f/flipboard/21483/1054c690/PubDec2025.png813.5 KiB802.8 KiB
News Centre div.flippy > a.flippy__inner > div.flippy__img-w > img.placeholder__item
hku.hk/f/flipboard/7740/1054c690/IMG_5829a.jpg789.4 KiB778.7 KiB
Current Students div.flippy > a.flippy__inner > div.flippy__img-w > img.placeholder__item
hku.hk/f/flipboard/21470/1054c690/currentstudent.JPG784.3 KiB773.6 KiB
HKU Summer Institute Summer Programmes 2026 Application opens now div.slick-track > a.flippy__inner > div.flippy__img-w > img.flippy__poster
hku.hk/f/poster/28842/527p0/HKUbannerRoll@1054.jpg695.7 KiB673.1 KiB
HKU in the Media div.flippy > a.flippy__inner > div.flippy__img-w > img.placeholder__item
hku.hk/f/flipboard/21504/1054c690/flipboard-hkuinthemedia.jpg644.3 KiB633.6 KiB
Teaching & Learning div.flippy > a.flippy__inner > div.flippy__img-w > img.placeholder__item
hku.hk/f/flipboard/7738/1054c690/tnl2024.jpg634.6 KiB623.9 KiB
Publicity on hku.hk div.flippy > a.flippy__inner > div.flippy__img-w > img.placeholder__item
hku.hk/f/flipboard/10567/1054c690/publicity.jpg598.6 KiB588.0 KiB
Could AI one day develop a mind? HKU professor examines the philosophical impli… div.caphoto__item > a.caphoto__img-w > div.caphoto__img-c > img.caphoto__img
hku.hk/f/photo/29010/864p0/Research5_Does%20AI%20Have%20a%20Mind@1728.jpg498.9 KiB450.4 KiB
div.slider__item > a > div.placeholder > img.placeholder__item div.slider__item > a > div.placeholder > img.placeholder__item
hku.hk/f/frontpage/29052/3840c2160/QS-Asia-University-Ranking-2026.jpg483.3 KiB435.7 KiB
Decentralising data collection for safer machine learning div.caphoto__item > a.caphoto__img-w > div.caphoto__img-c > img.caphoto__img
hku.hk/f/photo/29050/864p0/CoverStory4_A-Better-Way-to-Share@1728.jpg479.0 KiB430.5 KiB
Multimedia div.flippy > a.flippy__inner > div.flippy__img-w > img.placeholder__item
hku.hk/f/flipboard/7916/1054c690/flipboard-multimedia.jpg385.5 KiB374.8 KiB
Master of Arts in the field of Hong Kong Cultural Studies div.slick-track > a.flippy__inner > div.flippy__img-w > img.flippy__poster
hku.hk/f/poster/28943/527p0/mahkcs-in-hku-website-1000x1382@1054.jpg393.6 KiB371.1 KiB
Research div.flippy > a.flippy__inner > div.flippy__img-w > img.placeholder__item
hku.hk/f/flipboard/7739/1054c690/Research_2x_1054x694.jpg300.1 KiB289.4 KiB
div.slider__item > a > div.placeholder > img.placeholder__item div.slider__item > a > div.placeholder > img.placeholder__item
hku.hk/f/frontpage/29052/3840c2160/251104_HKU-Highly-Cited-Research_banner.jpg333.7 KiB286.7 KiB
U-Vision Online ul > li#banner_06 > a > img
hku.hk/f/banner/331/258c90/uv_banner_350x123.gif207.0 KiB129.0 KiB
U-Vision Online ul > li#banner_06 > a > img
hku.hk/f/banner/331/258c90/uv_banner_350x123@750.gif207.0 KiB129.0 KiB
30th Hong Kong Medical Forum ul > li#banner_03 > a > img
hku.hk/f/banner/28939/258c90/30th%20HKMF_W350xH123@750.png84.4 KiB78.6 KiB
HKU Summer Institute Summer Programmes 2026 Application opens now ul > li#banner_05 > a > img
hku.hk/f/banner/28843/258c90/HKUsmallBanner@750.jpg59.4 KiB53.7 KiB
DeepTech100 cohort 7 ul > li#banner_04 > a > img
/f/banner/29062/258c90/For HKU Web banner 350 x 123 px@75...58.6 KiB52.8 KiB
30th Hong Kong Medical Forum ul > li#banner_03 > a > img
hku.hk/f/banner/28939/258c90/30th%20HKMF_W350xH123.png43.8 KiB40.0 KiB
HKU Summer Institute Summer Programmes 2026 Application opens now ul > li#banner_05 > a > img
hku.hk/f/banner/28843/258c90/HKUsmallBanner.jpg40.0 KiB36.2 KiB
HKUSPACE ul > li#banner_01 > a > img
hku.hk/f/banner/14717/258c90/bannerSPACE@750.jpg38.3 KiB32.6 KiB
DeepTech100 cohort 7 ul > li#banner_04 > a > img
hku.hk/f/banner/29062/258c90/For%20HKU%20Web%20banner%20350%20x%20123%20px.png36.1 KiB32.3 KiB
Best .hk Website Awards 2016 div.page-foot__right > div.foot-award > a.foot-award__item > img.foot-award__logo
hku.hk/assets/img/besthk-logo-2016.png?t=2017051134.5 KiB31.0 KiB
HKU CEDARS - Centre of Development and Resources for Students ul > li#banner_02 > a > img
hku.hk/f/banner/27503/258c90/Untitled%20design.jpg22.8 KiB19.0 KiB
HKUSPACE ul > li#banner_01 > a > img
hku.hk/f/banner/14717/258c90/bannerSPACE.jpg21.2 KiB17.4 KiB
University Standard of Excellence in the WebAward 2014 div.page-foot__right > div.foot-award > a.foot-award__item > img.foot-award__logo
hku.hk/assets/img/2014_Standard_Winner.png?t=2016092116.0 KiB14.1 KiB
Master of Arts in the field of Hong Kong Cultural Studies ul > li#banner_04 > a > img
hku.hk/f/banner/28942/258c90/mahkcs-hku-banner-350x123px@750.gif25.7 KiB4.7 KiB

Each subpart has specific improvement strategies. Ideally, most of the LCP time should be spent on loading the resources, not within delays.

Why this matters

Performance issues directly impact user engagement and conversion rates.

headings: [map[key:label label:Subpart valueType:text] map[key:duration label:Duration valueType:ms]]
items: [map[duration:1003.239 label:Time to first byte subpart:timeToFirstByte] map[duration:4458.962 label:Resource load delay subpart:resourceLoadDelay] map[duration:968.347 label:Resource load duration subpart:resourceLoadDuration] map[duration:66.011 label:Element render delay subpart:elementRenderDelay]]
lhId: page-22-IMG
nodeLabel: Decentralising data collection for safer machine learning
path: 4,HTML,1,BODY,6,DIV,4,DIV,0,DIV,1,MAIN,1,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,A,0,DIV,0,IMG
selector: div.caphoto__item > a.caphoto__img-w > div.caphoto__img-c > img.caphoto__img
snippet: <img src="https://hku.hk/f/photo/29050/864p0/CoverStory4_A-Better-Way-to-Share@1728.…" srcset="/f/photo/29050/864p0/CoverStory4_A-Better-Way-to-Share@1728.jpg 2x" alt="Decentralising data collection for safer machine learning" class="caphoto__img placeholder__item">

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-22-IMG
nodeLabel: Decentralising data collection for safer machine learning
path: 4,HTML,1,BODY,6,DIV,4,DIV,0,DIV,1,MAIN,1,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,0,A,0,DIV,0,IMG
selector: div.caphoto__item > a.caphoto__img-w > div.caphoto__img-c > img.caphoto__img
snippet: <img src="https://hku.hk/f/photo/29050/864p0/CoverStory4_A-Better-Way-to-Share@1728.…" srcset="/f/photo/29050/864p0/CoverStory4_A-Better-Way-to-Share@1728.jpg 2x" alt="Decentralising data collection for safer machine learning" class="caphoto__img placeholder__item">

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.

URLProtocol
hku.hk/http/1.1
hku.hk/assets/css/index.css?t=20230414http/1.1
hku.hk/assets/js/device.min.js?t=20230414http/1.1
hku.hk/assets/js/high-contrast.js?t=20230414http/1.1
hku.hk/assets/img/hku-115.svg?t=1760950144http/1.1
hku.hk/assets/css/print.csshttp/1.1
hku.hk/assets/img/manifest.jsonhttp/1.1
hku.hk/f/frontpage/29052/3840c2160/260318_Website_3_Banner_CurrentV_3_EN.jpghttp/1.1
hku.hk/f/frontpage/29052/3840c2160/SGP%20Inaugural%20Week%201.pnghttp/1.1
hku.hk/f/frontpage/29052/3840c2160/260119_THE_Subject_Ranking_2026-07.jpghttp/1.1
hku.hk/f/frontpage/29052/3840c2160/260119_THE_Subject_Ranking_2026-08.jpghttp/1.1
hku.hk/f/frontpage/29052/3840c2160/251104_HKU-Highly-Cited-Research_banner.jpghttp/1.1
hku.hk/f/frontpage/29052/3840c2160/QS-Asia-University-Ranking-2026.jpghttp/1.1
hku.hk/assets/img/svg/icon_fb.svghttp/1.1
hku.hk/assets/img/svg/icon_ios.svghttp/1.1
hku.hk/assets/img/svg/icon_android.svghttp/1.1
hku.hk/assets/img/svg/icon_more.svghttp/1.1
hku.hk/assets/img/WARS-Triple-Gold-hku-color.png?t=20230901http/1.1
hku.hk/assets/img/besthk-logo-2016.png?t=20170511http/1.1
hku.hk/assets/img/2014_Standard_Winner.png?t=20160921http/1.1
hku.hk/assets/img/cad-27th.png?t=20210628http/1.1
hku.hk/assets/js/index.js?t=20230414http/1.1
hku.hk/assets/min/js/menu.js?t=20230414http/1.1
hku.hk/assets/min/js/mobile_menu.js?t=20230414http/1.1
hku.hk/assets/min/js/json_data.js?t=20230414http/1.1
hku.hk/assets/js/slide/banner.js?t=20230414http/1.1
hku.hk/assets/js/main.min.js?t=20230414http/1.1
hku.hk/assets/fonts/roboto-regular-webfont.woff2http/1.1
hku.hk/assets/fonts/roboto-medium-webfont.woff2http/1.1
hku.hk/assets/fonts/icomoon/fonts/wico.woff2http/1.1
hku.hk/assets/fonts/frankruhllibre-bold-webfont.woff2http/1.1
hku.hk/f/flipboard/7738/1054c690/tnl2024.jpghttp/1.1
hku.hk/f/flipboard/7740/1054c690/IMG_5829a.jpghttp/1.1
hku.hk/f/flipboard/21504/1054c690/flipboard-hkuinthemedia.jpghttp/1.1
hku.hk/f/flipboard/21471/1054c690/ProspectiveStudents.JPGhttp/1.1
hku.hk/f/flipboard/7739/1054c690/Research_2x_1054x694.jpghttp/1.1
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-1.jpghttp/1.1
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-2.jpghttp/1.1
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-3.jpghttp/1.1
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-4.jpghttp/1.1
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-5.jpghttp/1.1
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-6.jpghttp/1.1
hku.hk/f/frontpage/29052/1920c654/HKU_Miansite_Desktop_Fculties_Banner_Law.jpghttp/1.1
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-8.jpghttp/1.1
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-9.jpghttp/1.1
hku.hk/f/frontpage/29052/1920c654/img_bhv-bg-10.jpghttp/1.1
hku.hk/assets/img/home/img_bhv-bg-default.jpg?1598702724http/1.1
hku.hk/assets/fonts/frankruhllibre-medium-webfont.woff2http/1.1
hku.hk/f/frontpage/29052/1648c1112/221018_AdmissionOnHKUHomeBanner_4.jpeghttp/1.1
hku.hk/f/photo/29050/864p0/CoverStory4_A-Better-Way-to-Share.jpghttp/1.1
hku.hk/f/photo/29010/864p0/Research5_Does%20AI%20Have%20a%20Mind.jpghttp/1.1
/f/photo/29049/864p0/TeachingAndLearning2_Training Guardi...http/1.1
hku.hk/f/photo/29009/864p0/KnowledgeExchange3_Safe%20to%20Swallow_hero%202.jpghttp/1.1
hku.hk/f/poster/28943/527p0/mahkcs-in-hku-website-1000x1382.jpghttp/1.1
hku.hk/f/poster/28940/527p0/30thHKMF1000x1382.pnghttp/1.1
hku.hk/f/poster/28842/527p0/HKUbannerRoll.jpghttp/1.1
hku.hk/f/banner/14717/258c90/bannerSPACE.jpghttp/1.1
hku.hk/f/banner/27503/258c90/Untitled%20design.jpghttp/1.1
hku.hk/f/banner/28939/258c90/30th%20HKMF_W350xH123.pnghttp/1.1
hku.hk/f/banner/29062/258c90/For%20HKU%20Web%20banner%20350%20x%20123%20px.pnghttp/1.1
hku.hk/f/banner/28843/258c90/HKUsmallBanner.jpghttp/1.1
hku.hk/f/banner/331/258c90/uv_banner_350x123.gifhttp/1.1
hku.hk/assets/img/menu/icon_about-hku.pnghttp/1.1
hku.hk/assets/img/menu/icon_teaching-and-learning.pnghttp/1.1
hku.hk/assets/img/menu/icon_research.pnghttp/1.1
hku.hk/assets/img/menu/icon_knowledge-exchange.pnghttp/1.1
hku.hk/assets/img/menu/icon_faculties-and-departments.pnghttp/1.1
hku.hk/assets/img/menu/icon_libraries.pnghttp/1.1
hku.hk/assets/img/menu/icon_hku-portal.pnghttp/1.1
hku.hk/assets/img/menu/icon_prospective-students.pnghttp/1.1
hku.hk/assets/img/menu/icon_current.pnghttp/1.1
hku.hk/assets/img/menu/icon_staff.pnghttp/1.1
hku.hk/assets/img/menu/icon_alumni.pnghttp/1.1
hku.hk/assets/img/menu/icon_media.pnghttp/1.1
hku.hk/assets/img/menu/icon_visitor.pnghttp/1.1
hku.hk/assets/img/menu/icon_giving.pnghttp/1.1
hku.hk/assets/img/menu/icon_events.pnghttp/1.1
hku.hk/assets/img/menu/icon_publications-new.png?t=1626140938102http/1.1
hku.hk/assets/img/menu/icon_careers.png?t=1626140938102http/1.1
hku.hk/f/banner/14717/258c90/bannerSPACE@750.jpghttp/1.1
hku.hk/f/banner/27503/258c90/Untitled%20design@750.jpghttp/1.1
hku.hk/f/banner/28939/258c90/30th%20HKMF_W350xH123@750.pnghttp/1.1
/f/banner/29062/258c90/For HKU Web banner 350 x 123 px@75...http/1.1
hku.hk/f/banner/28942/258c90/mahkcs-hku-banner-350x123px@750.gifhttp/1.1
hku.hk/f/banner/28843/258c90/HKUsmallBanner@750.jpghttp/1.1
hku.hk/f/banner/331/258c90/uv_banner_350x123@750.gifhttp/1.1
hku.hk/assets/fonts/frankruhllibre-black-webfont.woff2http/1.1
hku.hk/assets/img/lib_slick/ajax-loader.gifhttp/1.1
hku.hk/f/photo/29050/864p0/CoverStory4_A-Better-Way-to-Share@1728.jpghttp/1.1
hku.hk/f/photo/29010/864p0/Research5_Does%20AI%20Have%20a%20Mind@1728.jpghttp/1.1
/f/photo/29049/864p0/TeachingAndLearning2_Training Guardi...http/1.1
/f/photo/29009/864p0/KnowledgeExchange3_Safe to Swallow_h...http/1.1
hku.hk/f/poster/28943/527p0/mahkcs-in-hku-website-1000x1382@1054.jpghttp/1.1
hku.hk/f/poster/28940/527p0/30thHKMF1000x1382@1054.pnghttp/1.1
hku.hk/f/poster/28842/527p0/HKUbannerRoll@1054.jpghttp/1.1
hku.hk/f/flipboard/21470/1054c690/currentstudent.JPGhttp/1.1
hku.hk/f/flipboard/21472/1054c690/flipboard-libraries.jpghttp/1.1
hku.hk/f/flipboard/21473/1054c690/flipboard-events.jpghttp/1.1
hku.hk/f/flipboard/7633/1054c690/GivingtoHKU2022_updated.PNGhttp/1.1
hku.hk/f/flipboard/21483/1054c690/PubDec2025.pnghttp/1.1
hku.hk/f/flipboard/7916/1054c690/flipboard-multimedia.jpghttp/1.1
hku.hk/f/flipboard/21501/1054c690/career.JPGhttp/1.1
hku.hk/f/flipboard/10567/1054c690/publicity.jpghttp/1.1
hku.hk/assets/img/favicon.icohttp/1.1

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.

URLTransfer SizeDuration
hku.hk/assets/css/index.css?t=20230414320.3 KiB3.1 s
hku.hk/assets/js/high-contrast.js?t=202304141.9 KiB1.2 s
hku.hk/assets/js/device.min.js?t=202304143.9 KiB1.2 s

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.

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

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.

ElementLayout shift score
Teaching & Learning News Centre Previous Next HKU in the Media Prospective Stud… div.content-container > main.page-content > div#main > div.flipboard
0.265
Teaching & Learning News Centre Previous Next HKU in the Media Prospective Stud… div.content-container > main.page-content > div#main > div.flipboard
0.001
中 Toggle menu panel div.page-head > div.container-wide > div.page-head__inner > div.page-head__inner-right
0.000
中 Toggle menu panel div.page-head > div.container-wide > div.page-head__inner > div.page-head__inner-right
0.000
中 Toggle menu panel div.page-head > div.container-wide > div.page-head__inner > div.page-head__inner-right
0.000

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 JavaScript files can reduce payload sizes and script parse time. Learn how to minify JavaScript.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 390 ms 7.3 KiB
URLTransfer SizeEst Savings
hku.hk/assets/js/slide/banner.js?t=2023041417.5 KiB7.3 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: 1.6 s 258.7 KiB
URLTransfer SizeEst Savings
hku.hk/assets/css/index.css?t=20230414319.7 KiB258.7 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: 2.0 s 344.2 KiB
URLTransfer SizeEst Savings
hku.hk/assets/js/index.js?t=20230414354.7 KiB171.8 KiB
www.googletagmanager.com/gtm.js?id=GTM-M9F2TJ6135.0 KiB68.8 KiB
www.googletagmanager.com/gtag/js?id=G-ZHLLDTLTMG&cx=c&gtm=4e64h1157.3 KiB65.9 KiB
script.hotjar.com/modules.6a0f3932cb1341a35c18.js56.1 KiB37.7 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
hku.hk/4.5 s17 ms5.5 ms
hku.hk/assets/js/index.js?t=202304142.2 s1.1 s30 ms
Unattributable1.8 s71 ms0.0 ms
www.googletagmanager.com/gtm.js?id=GTM-M9F2TJ6233 ms170 ms49 ms
www.googletagmanager.com/gtag/js?id=G-ZHLLDTLTMG&cx=c&gtm=4e64h1172 ms128 ms41 ms
script.hotjar.com/modules.6a0f3932cb1341a35c18.js152 ms125 ms21 ms
hku.hk/assets/js/slide/banner.js?t=20230414140 ms104 ms2.2 ms
hku.hk/assets/js/main.min.js?t=20230414115 ms56 ms4.2 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
Other4.1 s
Style & Layout1.9 s
Script Evaluation1.8 s
Rendering1.2 s
Parse HTML & CSS303 ms
Script Parsing & Compilation170 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
hku.hk/f/frontpage/29052/3840c2160/260119_THE_Subject_Ranking_2026-07.jpg4.5 MiB
hku.hk/f/frontpage/29052/3840c2160/260119_THE_Subject_Ranking_2026-08.jpg4.1 MiB
hku.hk/f/frontpage/29052/3840c2160/SGP%20Inaugural%20Week%201.png4.1 MiB
/f/photo/29049/864p0/TeachingAndLearning2_Training Guardi...1.8 MiB
hku.hk/f/poster/28940/527p0/30thHKMF1000x1382@1054.png1.4 MiB
/f/photo/29009/864p0/KnowledgeExchange3_Safe to Swallow_h...1.4 MiB
hku.hk/f/flipboard/21473/1054c690/flipboard-events.jpg1.3 MiB
hku.hk/f/frontpage/29052/3840c2160/260318_Website_3_Banner_CurrentV_3_EN.jpg1.0 MiB
hku.hk/f/flipboard/21501/1054c690/career.JPG1023.7 KiB
hku.hk/f/flipboard/21472/1054c690/flipboard-libraries.jpg996.5 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
HKUSPACE ul > li#banner_01 > a > img
hku.hk/f/banner/14717/258c90/bannerSPACE@750.jpg
HKU CEDARS - Centre of Development and Resources for Students ul > li#banner_02 > a > img
hku.hk/f/banner/27503/258c90/Untitled%20design@750.jpg
30th Hong Kong Medical Forum ul > li#banner_03 > a > img
hku.hk/f/banner/28939/258c90/30th%20HKMF_W350xH123@750.png
Master of Arts in the field of Hong Kong Cultural Studies ul > li#banner_04 > a > img
hku.hk/f/banner/28942/258c90/mahkcs-hku-banner-350x123px@750.gif
HKU Summer Institute Summer Programmes 2026 Application opens now ul > li#banner_05 > a > img
hku.hk/f/banner/28843/258c90/HKUsmallBanner@750.jpg
U-Vision Online ul > li#banner_06 > a > img
hku.hk/f/banner/331/258c90/uv_banner_350x123@750.gif
Best .hk Website Awards 2016 div.page-foot__right > div.foot-award > a.foot-award__item > img.foot-award__logo
hku.hk/assets/img/besthk-logo-2016.png?t=20170511
Triple Gold Award of the Web Accessibility Recognition Scheme 2022/23 div.page-foot__right > div.foot-award > a.foot-award__item > img.foot-award__logo
hku.hk/assets/img/WARS-Triple-Gold-hku-color.png?t=20230901
University Standard of Excellence in the WebAward 2014 div.page-foot__right > div.foot-award > a.foot-award__item > img.foot-award__logo
hku.hk/assets/img/2014_Standard_Winner.png?t=20160921
The 27th Annual Communicator Awards of Distinction div.page-foot__right > div.foot-award > a.foot-award__item > img.foot-award__logo
hku.hk/assets/img/cad-27th.png?t=20210628

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

●Optimize DOM size
●Optimize viewport for mobile
●Minify CSS
●User Timing marks and measures 5 user timings
●Avoid long main-thread tasks 12 long tasks found
●Avoid non-composited animations 27 animated elements found
●Page didn't prevent back/forward cache restoration
●Network Requests
●Network Round Trip Times 240 ms
●Server Backend Latencies 40 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 260 ms
○INP breakdown
77

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.

ARIA

Each ARIA `role` supports a specific subset of `aria-*` attributes. Mismatching these invalidates the `aria-*` attributes. Learn how to match ARIA attributes to their roles.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
2 div.section-hero__slider > div.slick-dots-container > ul.slick-dots > li#slick-slide01
2 div.caphoto__slider > div.slick-dots-container > ul.slick-dots > li#slick-slide11
1 div.flipboard__slider > div.slick-dots-container > ul.slick-dots > li#slick-slide20

Assistive technologies, like screen readers, can't interpret ARIA attributes with invalid values. Learn more about valid values for ARIA attributes.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
1 div.flipboard__slider > div.slick-dots-container > ul.slick-dots > li#slick-slide20

Focusable descendents within an `[aria-hidden="true"]` element prevent those interactive elements from being available to users of assistive technologies like screen readers. Learn how `aria-hidden` affects focusable elements.

Why this matters

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

Source: MDN Permissions-Policy

Failing Elements
1 div.section-hero__slider > div.slick-dots-container > ul.slick-dots > li#slick-slide00
3 div.section-hero__slider > div.slick-dots-container > ul.slick-dots > li#slick-slide02
4 div.section-hero__slider > div.slick-dots-container > ul.slick-dots > li#slick-slide03
5 div.section-hero__slider > div.slick-dots-container > ul.slick-dots > li#slick-slide04
6 div.section-hero__slider > div.slick-dots-container > ul.slick-dots > li#slick-slide05
1 div.caphoto__slider > div.slick-dots-container > ul.slick-dots > li#slick-slide10
3 div.caphoto__slider > div.slick-dots-container > ul.slick-dots > li#slick-slide12
4 div.caphoto__slider > div.slick-dots-container > ul.slick-dots > li#slick-slide13
2 div.flipboard__slider > div.slick-dots-container > ul.slick-dots > li#slick-slide21
3 div.flipboard__slider > div.slick-dots-container > ul.slick-dots > li#slick-slide22

When an input field doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more about input field labels.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.section-hero__cont > div.section-hero__slider > div.slick-list > div.slick-track div.section-hero__cont > div.section-hero__slider > div.slick-list > div.slick-track
A Better Way To Share Decentralising data collection for safer machine learning… div.caphoto__cont > div.caphoto__slider > div.slick-list > div.slick-track
Teaching & Learning News Centre Previous Next HKU in the Media Prospective Stud… div.container-wide > div.flipboard__slider > div.slick-list > div.slick-track
Master of Arts in the field of Hong Kong Cultural Studies div.flippy > div.slider--poster > div.slick-list > div.slick-track

When a toggle field doesn't have an accessible name, screen readers announce it with a generic name, making it unusable for users who rely on screen readers. Learn more about toggle fields.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.section-hero__slider > div.slick-list > div.slick-track > div.slider__item div.section-hero__slider > div.slick-list > div.slick-track > div.slider__item

These are opportunities to improve the usage of ARIA in your application which may enhance the experience for users of assistive technology, like a screen reader.

Contrast

Low-contrast text is difficult or impossible for many users to read. Learn how to provide sufficient color contrast.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Facebook div.page-foot__left > ul.page-foot__list > li.page-foot__item > a.page-foot__link
HKU IOS App div.page-foot__left > ul.page-foot__list > li.page-foot__item > a.page-foot__link
HKU Android App div.page-foot__left > ul.page-foot__list > li.page-foot__item > a.page-foot__link
Social Media and Apps div.page-foot__left > ul.page-foot__list > li.page-foot__item > a.page-foot__link
Careers div.page-foot__left > ul.page-foot__list > li.page-foot__item > a.page-foot__link
High Contrast div.page-foot__left > ul.page-foot__list > li.page-foot__item > a#switch-contrast-1
Maps & Facilities div.page-foot__left > ul.page-foot__list > li.page-foot__item > a.page-foot__link
Web Policies & Guidelines div.page-foot__left > ul.page-foot__list > li.page-foot__item > a.page-foot__link
Contact Us div.page-foot__left > ul.page-foot__list > li.page-foot__item > a.page-foot__link
Site Map div.page-foot__left > ul.page-foot__list > li.page-foot__item > a.page-foot__link
Privacy div.page-foot__left > ul.page-foot__list > li.page-foot__item > a.page-foot__link
Web Accessibility Statement div.page-foot__left > ul.page-foot__list > li.page-foot__item > a.page-foot__link
Copyright © 2026 The University of Hong Kong. All Rights Reserved. div.container-wide > div.page-foot__inner > div.page-foot__right > p.foot-copyright

These are opportunities to improve the legibility of your content.

Tables and lists

Screen readers have a specific way of announcing lists. Ensuring proper list structure aids screen reader output. Learn more about proper list structure.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
1 2 3 4 5 6 div.section-hero__cont > div.section-hero__slider > div.slick-dots-container > ul.slick-dots
1 2 3 4 div.caphoto__cont > div.caphoto__slider > div.slick-dots-container > ul.slick-dots
1 2 3 div.container-wide > div.flipboard__slider > div.slick-dots-container > ul.slick-dots

These are opportunities to improve the experience of reading tabular or list data using 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-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]`s are contained by their required parent element
●`[role]` values are valid
●`[aria-*]` attributes are valid and not misspelled
●Buttons have an accessible name
●Image elements have `[alt]` attributes
●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 use only permitted ARIA attributes
●Document has a `<title>` element
●`<html>` element has a `[lang]` attribute
●`<html>` element has a valid value for its `[lang]` attribute
●Links have a discernible name
●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.
●`[lang]` attributes have a valid value
●Heading elements appear in a sequentially-descending order
●`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.
●Document has a main landmark.
●Deprecated ARIA roles were not used
●Image elements do not have `[alt]` attributes that are redundant text.
○`[accesskey]` values are unique
○`button`, `link`, and `menuitem` elements have accessible names
○Elements with `role="dialog"` or `role="alertdialog"` have accessible names.
○ARIA `meter` elements have accessible names
○ARIA `progressbar` elements have accessible names
○Elements with the `role=text` attribute do not have focusable descendents.
○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
○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.
○`<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
○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 clickjacking with XFO or CSP
●Mitigate DOM-based XSS with Trusted Types
●Detected JavaScript libraries
●Page has valid source maps
○Redirects HTTP traffic to HTTPS
100

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.

○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
●Image elements have `[alt]` attributes
●Document has a valid `hreflang`
○robots.txt is valid
○Document has a valid `rel=canonical`

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