Lighthouse Desktop

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

SCORE

GRADE

FIX

REVIEW

PASS

INFO

Detailed Report

Audit breakdown by category with detailed findings.

Performance

Insights

Remove large, duplicate JavaScript modules from bundles to reduce unnecessary bytes consumed by network activity.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Polyfills and transforms enable older browsers to use new JavaScript features. However, many aren't necessary for modern browsers. Consider modifying your JavaScript build process to not transpile Baseline features, unless you know you must support older browsers. Learn why most sites can deploy ES6+ code without transpiling

Why this matters

Performance issues directly impact user engagement and conversion rates.

3rd party code can significantly impact load performance. Reduce and defer loading of 3rd party code to prioritize your page's content.

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

items: [map[node:map[type:text value:Total] score:0.121052] map[node:map[boundingRect:map[bottom:1821 height:535 left:0 right:1350 top:1286 width:1350] lhId:page-14-SECTION nodeLabel:NEWS More News © Sven Ellger / TUD, J.Dünnhaupt Apr 13, 2026 Two TUD researcher… path:1,HTML,1,BODY,1,DIV,4,MAIN,2,SECTION selector:body.pace-done > div#body-wrapper > main#main > section.news-teaser snippet:<section class="news-teaser"> type:node] score:0.11081] map[node:map[boundingRect:map[bottom:1086 height:319 left:856 right:1154 top:767 width:298] lhId:page-15-DIV nodeLabel:Responsible Electronics Whether smartphones, laptops, or televisions – everyda… path:1,HTML,1,BODY,1,DIV,4,MAIN,1,SECTION,1,DIV,0,DIV,1,DIV,0,DIV,0,DIV,2,DIV,0,DIV,0,DIV,0,A,1,DIV selector:div.content-teaser-item > div.relative > a.teaser > div.teaser-content snippet:<div class="teaser-content"> type:node] score:0.010214] map[node:map[boundingRect:map[bottom:923 height:40 left:130 right:160 top:883 width:30] lhId:page-16-::before nodeLabel:div.columns > div#uuid-0c895cf3515a4dd3a8964310d131c75b > button.owl-prev > ::before path:1,HTML,1,BODY,1,DIV,4,MAIN,1,SECTION,1,DIV,0,DIV,0,DIV,0,BUTTON,0,::before selector:div.columns > div#uuid-0c895cf3515a4dd3a8964310d131c75b > button.owl-prev > ::before snippet:<::before> type:node] score:2.8e-05]]

items: [map[node:map[type:text value:Total] score:0.001157] map[node:map[boundingRect:map[bottom:454 height:260 left:130 right:442 top:194 width:312] lhId:page-18-DIV nodeLabel:We are collaborative. We are excellent! path:1,HTML,1,BODY,1,DIV,4,MAIN,0,DIV,1,SECTION,0,DIV,0,DIV,0,DIV,1,DIV,0,DIV selector:div.columns > div.teaser > div.sp-teaser-content-wrapper > div.sp-teaser-content snippet:<div class="sp-teaser-content"> type:node] score:0.0005 subItems:map[items:[map[cause:Web font extra:map[type:url value:https://tu-dresden.de/++theme++tud.theme.webcms2/fonts/OpenSans/opensans-regular.woff2]]] type:subitems]] map[node:map[boundingRect:map[bottom:454 height:260 left:130 right:442 top:194 width:312] lhId:page-18-DIV nodeLabel:We are collaborative. We are excellent! path:1,HTML,1,BODY,1,DIV,4,MAIN,0,DIV,1,SECTION,0,DIV,0,DIV,0,DIV,1,DIV,0,DIV selector:div.columns > div.teaser > div.sp-teaser-content-wrapper > div.sp-teaser-content snippet:<div class="sp-teaser-content"> type:node] score:0.000443 subItems:map[items:[map[cause:Web font extra:map[type:url value:https://tu-dresden.de/++theme++tud.theme.webcms2/fonts/OpenSans/opensans-bold.woff2]]] type:subitems]] map[node:map[boundingRect:map[bottom:53 height:41 left:705 right:1155 top:12 width:450] lhId:page-19-DIV nodeLabel:Information for EN Search path:1,HTML,1,BODY,1,DIV,2,HEADER,0,DIV,0,DIV,2,DIV selector:header#header > div.row > div#portal-header > div#variable-header-container snippet:<div id="variable-header-container" data-toggler="gofuax-toggler" data-animate="slide-in-right slide-out-right" data-close-on-click="true"> type:node] score:0.000214]]

Consider setting font-display to swap or optional to ensure text is consistently visible. swap can be further optimized to mitigate layout shifts with font metric overrides.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Est Savings
tu-dresden.de/++theme++tud.theme.webcms2/fonts/OpenSans/opensans-light.woff2	2.1 s
tu-dresden.de/++theme++tud.theme.webcms2/fonts/OpenSans/opensans-semibold.woff2	2.0 s
tu-dresden.de/++theme++tud.theme.webcms2/fonts/OpenSans/opensans-bold.woff2	1.9 s
tu-dresden.de/++theme++tud.theme.webcms2/fonts/tud-icons.woff?6886	1.9 s
tu-dresden.de/++theme++tud.theme.webcms2/fonts/OpenSans/opensans-regular.woff2	1.7 s

Reducing the download time of images can improve the perceived load time of the page and LCP. Learn more about optimizing image size

Why this matters

Performance issues directly impact user engagement and conversion rates.

	URL	Resource Size	Est Savings
div.owl-item > div.teaser > div.teaser-bg > span.bg-picture-concrete `div.owl-item > div.teaser > div.teaser-bg > span.bg-picture-concrete`	/ressourcen/bilder/startseitenbanner/Mockup_4_TUD_ImageBr...	114.7 KiB	93.6 KiB
eine Baustelle der Zukunft: vernetzte Geräte wie Roboterarme, Kräne, Drohnen. m… `div.teaser-image > span.picture-element > picture > img`	/ressourcen/bilder/buehne/exzellenz/areas-of-excellence-c...	101.4 KiB	93.1 KiB
div.columns > div.teaser > div.teaser-bg > span.bg-picture-concrete `div.columns > div.teaser > div.teaser-bg > span.bg-picture-concrete`	/ressourcen/bilder/startseite/2026_Exzellenz-Header_final...	128.4 KiB	34.7 KiB
div.owl-item > div.teaser > div.teaser-bg > span.bg-picture-concrete `div.owl-item > div.teaser > div.teaser-bg > span.bg-picture-concrete`	/tu-dresden/exzellenz/ressourcen/bilder/film-we-are/120_f...	52.2 KiB	31.1 KiB
Oberflächen Exzitonen - ein gitterartiger Würfel aus Teilchen `div.teaser-image > span.picture-element > picture > img`	/ressourcen/bilder/buehne/exzellenz/bilder-der-exc/ct.qma...	33.9 KiB	25.7 KiB
Foto von Mohamed Elgendy. `div.teaser-image > span.picture-element > picture > img`	/med/mf/ressourcen/bilder/news/2026/Mi2.jpg/@@images/508a...	28.8 KiB	20.6 KiB
Exzellenzcluster PoL `div.teaser-image > span.picture-element > picture > img`	/ressourcen/bilder/buehne/exzellenz/bilder-der-exc/pol/19...	27.8 KiB	19.6 KiB
div.columns > div.teaser > div.teaser-bg > span.bg-picture-concrete `div.columns > div.teaser > div.teaser-bg > span.bg-picture-concrete`	/ressourcen/bilder/campus-navigator-placeit.jpg/@@images/...	27.4 KiB	19.2 KiB
ein Dirigent steht neben drei Menschengroßen Roboterarmen, jeder mit einemTakts… `div.teaser-image > span.picture-element > picture > img`	/ressourcen/bilder/buehne/exzellenz/roboter-sinfonie/@@im...	26.4 KiB	18.1 KiB
Logo of the Service Center Studies. Big S green, big C orange, big S blue, behi… `div.media-container > figure.media > span.picture-element > img`	/ressourcen/bilder/startseite/Logo_SCS_bunt.png/@@images/...	18.8 KiB	11.6 KiB
VIsualisierung des Phasenübergangs bei Solarzellen `div.teaser-image > span.picture-element > picture > img`	/ressourcen/bilder/buehne/exzellenz/rec2_pixelwg_Joerg-Ba...	19.2 KiB	11.0 KiB
Photo: A person with blonde hair points at a screen displaying a geometric diag… `div.teaser-image > span.picture-element > picture > img`	/ressourcen/bilder/startseite/Stills-00_00_00_02-Still003...	18.6 KiB	10.4 KiB
Rendering of a GaAs-based semiconductor sample approximately 20 micrometers in … `div.teaser-image > span.picture-element > picture > img`	/tu-dresden/newsportal/ressourcen/bilder/news-bilder/foto...	16.0 KiB	7.8 KiB
Bildcollage mit einem Porträtfoto von Juniorprofessorin Dorit Brixius und einem… `div.teaser-image > span.picture-element > picture > img`	/tu-dresden/newsportal/ressourcen/bilder/news-bilder/foto...	14.8 KiB	6.6 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:195.15 label:Time to first byte subpart:timeToFirstByte] map[duration:1551.107 label:Resource load delay subpart:resourceLoadDelay] map[duration:2795.661 label:Resource load duration subpart:resourceLoadDuration] map[duration:25.045 label:Element render delay subpart:elementRenderDelay]]

lhId: page-2-SPAN

nodeLabel: div.columns > div.teaser > div.teaser-bg > span.bg-picture-concrete

path: 1,HTML,1,BODY,1,DIV,4,MAIN,0,DIV,1,SECTION,0,DIV,0,DIV,0,DIV,0,DIV,0,SPAN

selector: div.columns > div.teaser > div.teaser-bg > span.bg-picture-concrete

snippet: <span style="background-image: url("https://tu-dresden.de/ressourcen/bilder/startseite/2…");" class="bg-picture-concrete bg-picture-l biggest" data-url="https://tu-dresden.de/ressourcen/bilder/startseite/2026_Exzellenz-Header_f…" data-alt="">

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-2-SPAN

nodeLabel: div.columns > div.teaser > div.teaser-bg > span.bg-picture-concrete

path: 1,HTML,1,BODY,1,DIV,4,MAIN,0,DIV,1,SECTION,0,DIV,0,DIV,0,DIV,0,DIV,0,SPAN

selector: div.columns > div.teaser > div.teaser-bg > span.bg-picture-concrete

Avoid chaining critical requests by reducing the length of chains, reducing the download size of resources, or deferring the download of unnecessary resources to improve page load.

Why this matters

Performance issues directly impact user engagement and conversion rates.

description: [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints help the browser establish a connection earlier in the page load, saving time when the first request for that origin is made. The following are the origins that the page preconnected to.

title: Preconnected origins

value: no origins were preconnected

description: Add [preconnect](https://developer.chrome.com/docs/lighthouse/performance/uses-rel-preconnect/) hints to your most important origins, but try to use no more than 4.

title: Preconnect candidates

value: No additional origins are good candidates for preconnecting

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Transfer Size	Duration
/++plone++production/++unique++2026-03-30T14:52:00.121084...	202.5 KiB	160 ms
tu-dresden.de/++theme++tud.theme.webcms2/css/common.css?version=None	58.9 KiB	80 ms
/++plone++static/++unique++2024-11-11 23:39:45.815496/plo...	3.6 KiB
/++plone++static/++unique++2024-11-11 23:39:45.815496/plo...	1.1 KiB
/++plone++production/++unique++2026-03-30T14:52:00.121084...	1.9 KiB

A long cache lifetime can speed up repeat visits to your page. Learn more about caching.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Request	Cache TTL	Transfer Size
/ressourcen/bilder/startseite/2026_Exzellenz-Header_final...	3600.0 s	129.0 KiB
tu-dresden.de/startseite/video-fuer-studieninteressierte/@@preview	3600.0 s	115.5 KiB
tu-dresden.de/++theme++tud.theme.webcms2/css/common.css?version=None	86400.0 s	58.9 KiB
tu-dresden.de/++theme++tud.theme.webcms2/fonts/tud-icons.woff?6886	86400.0 s	43.0 KiB
tu-dresden.de/++theme++tud.theme.webcms2/fonts/OpenSans/opensans-light.woff2	86400.0 s	17.9 KiB
tu-dresden.de/++theme++tud.theme.webcms2/fonts/OpenSans/opensans-semibold.woff2	86400.0 s	17.7 KiB
tu-dresden.de/++theme++tud.theme.webcms2/fonts/OpenSans/opensans-bold.woff2	86400.0 s	17.6 KiB
tu-dresden.de/++theme++tud.theme.webcms2/fonts/OpenSans/opensans-regular.woff2	86400.0 s	17.0 KiB
tu-dresden.de/++theme++tud.theme.webcms2/img/tud_claim_2025.svg	86400.0 s	13.6 KiB
tu-dresden.de/++theme++tud.theme.webcms2/img/eutopia-logo.svg	86400.0 s	11.1 KiB
tu-dresden.de/++theme++tud.theme.webcms2/img/tud-logo-white-en-2025-v2.svg	86400.0 s	8.9 KiB
tu-dresden.de/++theme++tud.theme.webcms2/img/icons/video-overlay_youtube.svg	86400.0 s	3.5 KiB
tu-dresden.de/++theme++tud.theme.webcms2/img/sachsen-signet-gruen.svg	86400.0 s	2.9 KiB
tu-dresden.de/++plone++tud.addons.webcms/mockup/translate-catalog.js	86400.0 s	2.0 KiB
tu-dresden.de/++theme++tud.theme.webcms2/img/tud-logo-sliver.svg	86400.0 s	643 B

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

Diagnostics

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 40 ms 47.5 KiB

URL	Transfer Size	Est Savings
tu-dresden.de/++theme++tud.theme.webcms2/css/common.css?version=None	58.4 KiB	47.5 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: 120 ms 117.3 KiB

URL	Transfer Size	Est Savings
/++plone++production/++unique++2026-03-30T14:52:00.121084...	201.6 KiB	79.5 KiB
matomo.tu-dresden.de/matomo.js	66.4 KiB	37.9 KiB

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: 0.0 ms 25.7 KiB

URL	Transfer Size	Est Savings
/++plone++production/++unique++2026-03-30T14:52:00.121084...	202.0 KiB	25.7 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
Free State of Saxony modern coat of arms `div.row > div.row > div.columns > img`	tu-dresden.de/++theme++tud.theme.webcms2/img/sachsen-signet-gruen.svg
Bildcollage mit einem Porträtfoto von Juniorprofessorin Dorit Brixius und einem… `div.teaser-image > span.picture-element > picture > img`	/tu-dresden/newsportal/ressourcen/bilder/news-bilder/foto...
Rendering of a GaAs-based semiconductor sample approximately 20 micrometers in … `div.teaser-image > span.picture-element > picture > img`	/tu-dresden/newsportal/ressourcen/bilder/news-bilder/foto...
Foto von Mohamed Elgendy. `div.teaser-image > span.picture-element > picture > img`	/med/mf/ressourcen/bilder/news/2026/Mi2.jpg/@@images/508a...
Photo: A person with blonde hair points at a screen displaying a geometric diag… `div.teaser-image > span.picture-element > picture > img`	/ressourcen/bilder/startseite/Stills-00_00_00_02-Still003...
ein Dirigent steht neben drei Menschengroßen Roboterarmen, jeder mit einemTakts… `div.teaser-image > span.picture-element > picture > img`	/ressourcen/bilder/buehne/exzellenz/roboter-sinfonie/@@im...
VIsualisierung des Phasenübergangs bei Solarzellen `div.teaser-image > span.picture-element > picture > img`	/ressourcen/bilder/buehne/exzellenz/rec2_pixelwg_Joerg-Ba...
eine Baustelle der Zukunft: vernetzte Geräte wie Roboterarme, Kräne, Drohnen. m… `div.teaser-image > span.picture-element > picture > img`	/ressourcen/bilder/buehne/exzellenz/areas-of-excellence-c...
Oberflächen Exzitonen - ein gitterartiger Würfel aus Teilchen `div.teaser-image > span.picture-element > picture > img`	/ressourcen/bilder/buehne/exzellenz/bilder-der-exc/ct.qma...
Exzellenzcluster PoL `div.teaser-image > span.picture-element > picture > img`	/ressourcen/bilder/buehne/exzellenz/bilder-der-exc/pol/19...
Logo: TUD Dresden University of Technology `div#portal-header > div#portal-logo > a > img.white`	tu-dresden.de/++theme++tud.theme.webcms2/img/tud-logo-white-en-2025-v2.svg
EUTOPIA Alliance of 10 European Universities homepage `div.row > div.columns > a > img`	tu-dresden.de/++theme++tud.theme.webcms2/img/eutopia-logo.svg
Trademark and Claim of TUD: TUD \| The Collaborative University - inventive. tra… `div.border > div.row > div.columns > img`	tu-dresden.de/++theme++tud.theme.webcms2/img/tud_claim_2025.svg

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

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Element	Layout shift score
NEWS More News © Sven Ellger / TUD, J.Dünnhaupt Apr 13, 2026 Two TUD researcher… `body.pace-done > div#body-wrapper > main#main > section.news-teaser`	0.111
Responsible Electronics Whether smartphones, laptops, or televisions – everyda… `div.content-teaser-item > div.relative > a.teaser > div.teaser-content`	0.010
We are collaborative. We are excellent! `div.columns > div.teaser > div.sp-teaser-content-wrapper > div.sp-teaser-content`	0.001
We are collaborative. We are excellent! `div.columns > div.teaser > div.sp-teaser-content-wrapper > div.sp-teaser-content`	0.000
Information for EN Search `header#header > div.row > div#portal-header > div#variable-header-container`	0.000
div.columns > div#uuid-0c895cf3515a4dd3a8964310d131c75b > button.owl-prev > ::before `div.columns > div#uuid-0c895cf3515a4dd3a8964310d131c75b > button.owl-prev > ::before`	0.000

●Time to Interactive 1.8 s

●Document request latency

●Optimize DOM size

●Forced reflow

●Modern HTTP

●Optimize viewport for mobile

●Max Potential First Input Delay 40 ms

●Minify CSS

●Avoids enormous network payloads Total size was 1,307 KiB

●JavaScript execution time 0.2 s

●Minimizes main-thread work 0.6 s

●Page didn't prevent back/forward cache restoration

●Network Requests

●Network Round Trip Times 40 ms

●Server Backend Latencies 560 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 110 ms

○INP breakdown

○User Timing marks and measures

○Avoid long main-thread tasks

○Avoid non-composited animations

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

Some ARIA parent roles must contain specific child roles to perform their intended accessibility functions. Learn more about roles and required children elements.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
© TUD University of Excellence TUD has been one of Germany’s Universities of E… `section.content-teaser-box > div.row > div.columns > div.teaser-box`
APR 22 2026 Gewerbliche Schutzrechte in der Praxis - Teil II - Patentrecherch… `section.event-slider > div.row > div.columns > div.owl-carousel`
© AVANGA Filmproduktion VIDEO: WE ARE TUD MORE © CD BROCHURE: KNOWLEDGE FOR… `div.banner-box-background > div.row > div.columns > div.owl-carousel`

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
Read more University of Excellence `div.owl-item > div.content-teaser-item > div.more-wrapper > a.more`
Read more Robotics of the future `div.owl-item > div.content-teaser-item > div.more-wrapper > a.more`
Read more Responsible Electronics `div.owl-item > div.content-teaser-item > div.more-wrapper > a.more`

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
© TUD University of Excellence TUD has been one of Germany’s Universities of E… `section.content-teaser-box > div.row > div.columns > div.teaser-box`
APR 22 2026 Gewerbliche Schutzrechte in der Praxis - Teil II - Patentrecherch… `section.event-slider > div.row > div.columns > div.owl-carousel`
© AVANGA Filmproduktion VIDEO: WE ARE TUD MORE © CD BROCHURE: KNOWLEDGE FOR… `div.banner-box-background > div.row > div.columns > div.owl-carousel`

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.

Names and labels

Link text (and alternate text for images, when used as links) that is discernible, unique, and focusable improves the navigation experience for screen reader users. Learn how to make links accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.formatted > div.contact-block > p.tel > a.ms-text `div.formatted > div.contact-block > p.tel > a.ms-text`
div.formatted > div.contact-block > p > a.ms-m-href `div.formatted > div.contact-block > p > a.ms-m-href`

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
1 `div.columns > div.teaser-box > div.owl-dots > button.owl-dot`
2 `div.columns > div.teaser-box > div.owl-dots > button.owl-dot`

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

●`[role]` values are valid

●`[aria-*]` attributes have valid values

●`[aria-*]` attributes are valid and not misspelled

●Buttons have an accessible name

●Image elements have `[alt]` attributes

●`[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

●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

●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

●`<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

●Uses ARIA roles only on compatible elements

●Identical links have the same purpose.

●Elements with visible text labels have matching accessible names.

○`[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

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

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

○ARIA toggle fields have accessible names

○ARIA `tooltip` elements have accessible names

○ARIA `treeitem` elements have accessible names

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

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

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

○ARIA IDs are unique

○No form fields have multiple labels

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

○Input buttons have discernible text.

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

○Form elements have associated labels

○Links are distinguishable without relying on color.

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

○`<object>` elements have alternate text

○Select elements have associated label elements.

○Skip links are focusable.

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

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

○`[lang]` attributes have a valid value

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

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

○All heading elements contain content.

○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.

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.

Source	Description
/matomo.php?action_name=Technische%20Universit%C3%A4t%20D...	`Failed to load resource: the server responded with a status of 502 (Bad Gateway)`

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL	Map URL
/++plone++production/++unique++2026-03-30T14:52:00.121084...	/++plone++production/++unique++2026-03-30T14:52:00.121084...

●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

○Redirects HTTP traffic to HTTPS

○Mitigate clickjacking with XFO or CSP

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

●robots.txt is valid

●Image elements have `[alt]` attributes

●Document has a valid `hreflang`

●Document has a valid `rel=canonical`