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

Audit breakdown by category with detailed findings.

80

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
schalke04.de/content/themes/fcschalke04/assets/js/main.js?17855081873600.0 s222.9 KiB
schalke04.de/firebase/static/js/main.js?ver=release/1.2.9-202607293600.0 s212.8 KiB
/content/themes/fcschalke04/assets/css/fcschalke04.css?ve...3600.0 s170.9 KiB
/content/themes/fcschalke04/assets/fonts/fontawesome-webf...3600.0 s130.1 KiB
schalke04.de/content/themes/fcschalke04/assets/images/membership-banner-bg.jpg3600.0 s128.2 KiB
/content/themes/fcschalke04/assets/fonts/fontawesome-webf...3600.0 s97.1 KiB
/content/themes/fcschalke04/assets/fonts/fontawesome-webf...3600.0 s96.9 KiB
/content/themes/fcschalke04/assets/fonts/fontawesome-webf...3600.0 s96.1 KiB
/content/themes/fcschalke04/assets/fonts/fontawesome-webf...3600.0 s75.7 KiB
/partner/intern/cw_31_2026_atalanta_LB1/img/260617_Schalk...3600.0 s58.2 KiB
/content/themes/fcschalke04/assets/images/logo-veltins.sv...3600.0 s52.6 KiB
/content/themes/fcschalke04/assets/images/logo-veltins-bw...3600.0 s52.5 KiB
/content/themes/fcschalke04/assets/images/logo-veltins-bw...3600.0 s52.4 KiB
/configs/00002b96-febe6ac7-3aab-3ceb-b0d2-6365f1df7e93/58...180.0 s36.4 KiB
/partner/intern/cw_31_2026_Business_Kreisel_LB2/img/26070...3600.0 s43.2 KiB
schalke04.de/content/themes/fcschalke04/assets/fonts/fcs04-icons.svg3600.0 s31.6 KiB
l.ecn-ldr.de/loader/loader.js180.0 s23.5 KiB
schalke04.de/content/global/teams/ksv-hessen-kassel.png3600.0 s21.8 KiB
/partner/intern/cw_31_2026_atalanta_LB1/img/260617_Schalk...3600.0 s21.7 KiB
/content/themes/fcschalke04/assets/js/vendor/requirejs/re...3600.0 s21.6 KiB
/partner/intern/cw_31_2026_Business_Kreisel_LB2/img/26070...3600.0 s20.4 KiB
cdn.jsdelivr.net/npm/hls.js@latest604800.0 s159.9 KiB
l.ecn-ldr.de/core/core.js180.0 s13.5 KiB
/content/themes/fcschalke04/assets/js/vendor/slick-carous...3600.0 s15.2 KiB
app.usercentrics.eu/browser-ui/latest/loader.js3600.0 s10.8 KiB
schalke04.de/content/global/teams/fc-schalke-04.png3600.0 s9.8 KiB
/content/themes/fcschalke04/assets/images/logo-boeklunder...3600.0 s9.8 KiB
/content/themes/fcschalke04/assets/images/logo-boeklunder...3600.0 s9.8 KiB
/content/themes/fcschalke04/assets/images/logo-boeklunder...3600.0 s9.8 KiB
schalke04.de/content/themes/fcschalke04/assets/fonts/fcs04-icons.eot3600.0 s9.4 KiB
schalke04.de/content/themes/fcschalke04/assets/fonts/fcs04-icons.ttf3600.0 s9.3 KiB
schalke04.de/content/themes/fcschalke04/assets/fonts/fcs04-icons.woff3600.0 s9.3 KiB
/content/themes/fcschalke04/assets/fonts/fcs04-icons.woff...3600.0 s9.3 KiB
playout.3qsdn.com/player/css/s04.css3600.0 s8.9 KiB
/content/themes/fcschalke04/assets/images/logo-merkur.png...3600.0 s8.7 KiB
/content/themes/fcschalke04/assets/images/sponsor_logo_he...3600.0 s5.9 KiB
/beacon.min.js/v4513226cdae34746b4dedf0b4dfa099e178179150...86400.0 s11.3 KiB
/SIE/?Q_ZID=ZN_3RbQBel717pvO3I3600.0 s5.1 KiB
/content/themes/fcschalke04/assets/js/modernizr-custom.js...3600.0 s5.0 KiB
/dxjsmodule/941.769e075aa2ef88969a43.chunk.js?Q_CLIENTVER...604800.0 s38.2 KiB
/content/themes/fcschalke04/assets/js/vendor/waypoints/li...3600.0 s4.7 KiB
/content/themes/fcschalke04/assets/images/logo-knappschaf...3600.0 s4.6 KiB
/content/themes/fcschalke04/assets/images/logo-knappschaf...3600.0 s4.3 KiB
/content/themes/fcschalke04/assets/images/logo-knappschaf...3600.0 s4.2 KiB
/content/themes/fcschalke04/assets/images/logo-merkur_sw....3600.0 s4.2 KiB
/content/themes/fcschalke04/assets/images/logo-merkur_sw....3600.0 s4.2 KiB
/content/themes/fcschalke04/assets/images/sponsor_logo_he...3600.0 s4.1 KiB
/content/themes/fcschalke04/assets/images/Footer_Blaklade...3600.0 s4.1 KiB
/content/themes/fcschalke04/assets/images/sponsor_logo_he...3600.0 s4.0 KiB
/content/themes/fcschalke04/assets/images/Footer_Blaklade...3600.0 s4.0 KiB
/content/themes/fcschalke04/assets/images/Footer_Blaklade...3600.0 s4.0 KiB
/content/themes/fcschalke04/assets/images/PERF-11ts-lette...3600.0 s3.3 KiB
schalke04.de/content/themes/fcschalke04/assets/social/style.css?ver=5.9.33600.0 s3.0 KiB
/content/themes/fcschalke04/assets/images/PERF-11ts-lette...3600.0 s2.7 KiB
/content/themes/fcschalke04/assets/images/PERF-11ts-lette...3600.0 s2.7 KiB
partner.schalke04.de/partner/intern/cw_31_2026_atalanta_LB1/css/normalize.css3600.0 s2.4 KiB
schalke04.de/content/themes/fcschalke04/assets/images/members/sticker.svg3600.0 s2.2 KiB
/dxjsmodule/881.aef18691518ab4d98fec.chunk.js?Q_CLIENTVER...604800.0 s17.8 KiB
/content/themes/fcschalke04/assets/images/logo-stoelting....3600.0 s2.2 KiB
/content/themes/fcschalke04/assets/images/logo-stoelting-...3600.0 s2.2 KiB
/content/themes/fcschalke04/assets/images/logo-stoelting-...3600.0 s2.1 KiB
schalke04.de/content/themes/fcschalke04/assets/images/Sidebar_User.svg3600.0 s1.8 KiB
/content/themes/fcschalke04/assets/images/Hagedorn_Logo_W...3600.0 s1.8 KiB
schalke04.de/content/themes/fcschalke04/assets/fonts/slick.woff3600.0 s1.7 KiB
/content/themes/fcschalke04/assets/images/Footer_Beumer_R...3600.0 s1.7 KiB
/content/themes/fcschalke04/assets/images/Footer_Beumer_s...3600.0 s1.6 KiB
/content/themes/fcschalke04/assets/images/Hagedorn_Logo_W...3600.0 s1.6 KiB
/content/themes/fcschalke04/assets/images/Hagedorn_Logo_W...3600.0 s1.6 KiB
/content/themes/fcschalke04/assets/images/Footer_Beumer_s...3600.0 s1.5 KiB
schalke04.de/content/themes/fcschalke04/assets/js/modules/slider.js?17855081873600.0 s1.5 KiB
schalke04.de/content/themes/fcschalke04/assets/fonts/icomoon/icomoon.ttf?bo59w3600.0 s1.4 KiB
schalke04.de/content/themes/fcschalke04/assets/images/Icon_Glueckauf.svg3600.0 s1.3 KiB
/content/themes/fcschalke04/assets/js/modules/hospitality...3600.0 s1.1 KiB
/content/themes/fcschalke04/assets/images/HRS_BTC_logo_re...3600.0 s935 B
/content/themes/fcschalke04/assets/images/HRS_BTC_logo_bl...3600.0 s901 B
app.usercentrics.eu/session/1px.png?settingsId=ax0_-X4vk1800.0 s821 B
/content/themes/fcschalke04/assets/images/HRS_BTC_logo_bl...3600.0 s827 B
schalke04.de/content/themes/fcschalke04/assets/images/tiktok_icon.svg3600.0 s826 B
schalke04.de/content/themes/fcschalke04/assets/js/modules/scroll.js?17855081873600.0 s799 B
schalke04.de/content/themes/fcschalke04/assets/images/ajax-loader.gif3600.0 s710 B
partner.schalke04.de/partner/intern/cw_31_2026_atalanta_LB1/js/plugins.js3600.0 s628 B
/content/themes/fcschalke04/assets/js/vendor/conditioner-...3600.0 s604 B
/partner/intern/cw_31_2026_Business_Kreisel_LB2/js/plugin...3600.0 s524 B
schalke04.de/content/themes/fcschalke04/assets/images/flags/4x3/de.svg3600.0 s446 B
/content/themes/fcschalke04/assets/js/modules/marketing.j...3600.0 s381 B
partner.schalke04.de/partner/intern/cw_31_2026_atalanta_LB1/js/main.js3600.0 s237 B
partner.schalke04.de/partner/intern/cw_31_2026_Business_Kreisel_LB2/js/main.js3600.0 s205 B
/content/themes/fcschalke04/assets/css/fcschalke04.css?ve...3600.0 s0 B
/partner/intern/cw_31_2026_atalanta_LB1/img/260617_Schalk...3600.0 s0 B
/partner/intern/cw_31_2026_Business_Kreisel_LB2/img/26070...3600.0 s0 B
/beacon.min.js/v4513226cdae34746b4dedf0b4dfa099e178179150...86400.0 s0 B
/beacon.min.js/v4513226cdae34746b4dedf0b4dfa099e178179150...86400.0 s0 B
/beacon.min.js/v4513226cdae34746b4dedf0b4dfa099e178179150...86400.0 s0 B
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/beacon.min.js/v4513226cdae34746b4dedf0b4dfa099e178179150...86400.0 s0 B
/beacon.min.js/v4513226cdae34746b4dedf0b4dfa099e178179150...86400.0 s0 B
partner.schalke04.de/partner/intern/cw_31_2026_atalanta_LB1/css/normalize.css3600.0 s0 B
partner.schalke04.de/partner/intern/cw_31_2026_atalanta_LB1/css/normalize.css3600.0 s0 B
partner.schalke04.de/partner/intern/cw_31_2026_atalanta_LB1/js/plugins.js3600.0 s0 B
/partner/intern/cw_31_2026_Business_Kreisel_LB2/js/plugin...3600.0 s0 B
partner.schalke04.de/partner/intern/cw_31_2026_atalanta_LB1/js/plugins.js3600.0 s0 B
/partner/intern/cw_31_2026_Business_Kreisel_LB2/js/plugin...3600.0 s0 B
partner.schalke04.de/partner/intern/cw_31_2026_atalanta_LB1/js/main.js3600.0 s0 B
partner.schalke04.de/partner/intern/cw_31_2026_Business_Kreisel_LB2/js/main.js3600.0 s0 B
partner.schalke04.de/partner/intern/cw_31_2026_atalanta_LB1/js/main.js3600.0 s0 B
partner.schalke04.de/partner/intern/cw_31_2026_Business_Kreisel_LB2/js/main.js3600.0 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.

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:35.332 source:map[column:36 line:1705 type:source-location url:https://schalke04.de/content/themes/fcschalke04/assets/js/vendor/requirejs/require.js?ver=release/1.2.9-20260729 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:0.316 source:map[type:text value:[unattributed]]] map[reflowTime:28.261 source:map[column:17 line:6451 type:source-location url:https://schalke04.de/content/themes/fcschalke04/assets/js/main.js?1785508187 urlProvider:network]] map[reflowTime:1.968 source:map[column:30 line:6304 type:source-location url:https://schalke04.de/content/themes/fcschalke04/assets/js/main.js?1785508187 urlProvider:network]] map[reflowTime:0.277 source:map[column:51 line:6312 type:source-location url:https://schalke04.de/content/themes/fcschalke04/assets/js/main.js?1785508187 urlProvider:network]] map[reflowTime:0.289 source:map[column:45 line:6323 type:source-location url:https://schalke04.de/content/themes/fcschalke04/assets/js/main.js?1785508187 urlProvider:network]] map[reflowTime:4.119 source:map[column:53 line:6451 type:source-location url:https://schalke04.de/content/themes/fcschalke04/assets/js/main.js?1785508187 urlProvider:network]] map[reflowTime:0.418 source:map[column:50 line:6413 type:source-location url:https://schalke04.de/content/themes/fcschalke04/assets/js/main.js?1785508187 urlProvider:network]]]

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-0-IMG
nodeLabel: 20260731-Muslic
path: 3,HTML,2,BODY,6,DIV,0,ARTICLE,5,SECTION,0,DIV,0,DIV,0,DIV,0,DIV,0,DIV,1,DIV,0,DIV,1,DIV,0,A,0,DIV,0,IMG
selector: div.stage-element > a > div.stage-media > img.img-fluid
snippet: <img class="img-fluid initial lazyloading" src="https://storage.schalke04.de/sites/1/2026/07/20260731-muslic-992x558.jpg" srcset="https://storage.schalke04.de/sites/1/2026/07/20260731-muslic-375x211.jpg 3…" sizes="(min-width: 1920px) 1280px, (min-width: 1440px) 960px, (min-width: 1200px)…" alt="20260731-Muslic" data-was-processed="true">

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

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
Schmuckgrafik Ausweichtrikot div.module > a > figure > img.img-fluid
storage.schalke04.de/sites/1/2026/07/260710_third_877x400.jpg113.9 KiB67.6 KiB
260511_Keyvisual_SGU_HomepageBG div.stage-element > a > div.stage-media > img.img-fluid
storage.schalke04.de/sites/1/2026/05/260511_keyvisual_sgu_homepagebg-992x558.jpg104.3 KiB49.0 KiB
Werbebanner S04 TV+: ‚Hier läuft Schalke. Jetzt abonnieren!‘; Jubelszene in Bla… div.module > a > figure > img.img-fluid
storage.schalke04.de/sites/1/2026/07/s04tvplus_motiv2_877x400.jpg81.9 KiB24.8 KiB
KSV Hessen Kassel div.games-body > div.games-team > div.team-logo > img
schalke04.de/content/global/teams/ksv-hessen-kassel.png21.4 KiB19.2 KiB
260731_VELTINS-Arena-Panorama a.teaser-inner-link > div.card-img-top > div.teaser-image > img.img-fluid
storage.schalke04.de/sites/1/2026/07/260731_veltins-arena-panorama-375x211.jpg23.5 KiB19.1 KiB
260730_Kassel_Stadion a.teaser-inner-link > div.card-img-top > div.teaser-image > img.img-fluid
storage.schalke04.de/sites/1/2026/07/260730_kassel_stadion-375x211.jpg25.7 KiB14.4 KiB
20260717-Heimtrikot-HD700 div.col-xl-8 > a.card-img-top > div.teaser-image > img.img-fluid
storage.schalke04.de/sites/1/2026/07/20260717-heimtrikot-hd700-576x324.jpg32.9 KiB11.9 KiB
FC Schalke 04 div.games-body > div.games-team > div.team-logo > img
schalke04.de/content/global/teams/fc-schalke-04.png9.5 KiB7.8 KiB
20260728-S04RealHD700 a.teaser-inner-link > div.card-img-top > div.teaser-image > img.img-fluid
storage.schalke04.de/sites/1/2026/07/20260728-s04realhd700-375x211.jpg18.9 KiB7.5 KiB

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

Diagnostics

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.

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failure reasonFailure type
Pages whose main resource has cache-control:no-store cannot enter back/forward cache.Not actionable
Back/forward cache is disabled because some JavaScript network request received resource with Cache-Control: no-store header.Not actionable

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.

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
Other1.2 s
Script Evaluation678 ms
Style & Layout372 ms
Script Parsing & Compilation92 ms
Rendering86 ms
Parse HTML & CSS72 ms
Garbage Collection51 ms

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
Werbebanner S04 TV+: ‚Hier läuft Schalke. Jetzt abonnieren!‘; Jubelszene in Bla… div.module > a > figure > img.img-fluid
storage.schalke04.de/sites/1/2026/07/s04tvplus_motiv2_877x400.jpg
Schmuckgrafik Ausweichtrikot div.module > a > figure > img.img-fluid
storage.schalke04.de/sites/1/2026/07/260710_third_877x400.jpg
Schmuckgrafik Frauen-Trikot div.module > a > figure > img.img-fluid
storage.schalke04.de/sites/1/2026/07/260720_frauen_433x400.jpg
Logo Knappschaft Kliniken ul > li > a > img.img-fluid
/content/themes/fcschalke04/assets/images/logo-knappschaf...
Logo Hegmanns Gruppe ul > li > a > img.img-fluid
/content/themes/fcschalke04/assets/images/sponsor_logo_he...
Logo Merkur ul > li > a > img.img-fluid
/content/themes/fcschalke04/assets/images/logo-merkur.png...
Logo Blåkläder ul > li > a > img.img-fluid
/content/themes/fcschalke04/assets/images/Footer_Blaklade...
Logo Hagedorn ul > li > a > img.img-fluid
/content/themes/fcschalke04/assets/images/Hagedorn_Logo_W...

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

Time to Interactive 2.2 s
Max Potential First Input Delay 70 ms
Layout shift culprits
Document request latency
Optimize DOM size
LCP breakdown
Modern HTTP
Optimize viewport for mobile
Minify CSS
Reduce unused CSS
JavaScript execution time 0.7 s
Avoid long main-thread tasks 2 long tasks found
Avoid non-composited animations 31 animated elements found
Network Requests
Network Round Trip Times 70 ms
Server Backend Latencies 70 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 120 ms
Avoid large layout shifts 3 layout shifts found
INP breakdown
User Timing marks and measures
84

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
4 div.stage-container > div.stage-slider > ul.slick-dots > li#slick-slide13

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
1 2 3 4 5 div.col-xl-16 > div.stage-container > div.stage-slider > ul.slick-dots

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
Aus vielen Anteilen wird gemeinsame Stärke: Jetzt Anteile an der Auf Schalke eG… div.stage-container > div.stage-slider > div.slick-list > div.slick-track
Fußballfest gegen Real Madrid: Wenige Kontingente in den VIP-Bereichen erhältli… div.module > div.card-deck > div.slick-list > div.slick-track

Using ARIA attributes in roles where they are prohibited can mean that important information is not communicated to users of assistive technologies. Learn more about prohibited ARIA roles.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
Suche umschalten div.header-nav > div.nav-meta > div.meta-search > div.btn

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

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
div.col-xl-24 > div > div.module > iframe#campaign-708011-lg div.col-xl-24 > div > div.module > iframe#campaign-708011-lg
div.col-xl-24 > div > div.module > iframe#campaign-708012-lg div.col-xl-24 > div > div.module > iframe#campaign-708012-lg

These are opportunities to improve the semantics of the controls in your application. This may enhance the experience for users of assistive technology, like a screen reader.

Interactive controls are keyboard focusable
Interactive elements indicate their purpose and state
The page has a logical tab order
Visual order on the page follows DOM order
User focus is not accidentally trapped in a region
The user's focus is directed to new content added to the page
HTML5 landmark elements are used to improve navigation
Offscreen content is hidden from assistive technology
Custom controls have associated labels
Custom controls have ARIA roles
`[aria-hidden="true"]` is not present on the document `<body>`
`[role]`s have all required `[aria-*]` attributes
`[role]`s are contained by their required parent element
`[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
Form elements have associated labels
`[user-scalable="no"]` is not used in the `<meta name="viewport">` element and the `[maximum-scale]` attribute is not less than 5.
ARIA attributes are used as specified for the element's role
Elements with `role="dialog"` or `role="alertdialog"` have accessible names.
`[aria-hidden="true"]` elements do not contain focusable descendents
ARIA toggle fields have accessible names
Background and foreground colors have a sufficient contrast ratio
Document has a `<title>` element
`<html>` element has a `[lang]` attribute
`<html>` element has a valid value for its `[lang]` attribute
Links are distinguishable without relying on color.
Links have a discernible name
Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).
List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements
No element has a `[tabindex]` value greater than 0
Touch targets have sufficient size and spacing.
`[lang]` attributes have a valid value
Heading elements appear in a sequentially-descending order
Document has a main landmark.
Deprecated ARIA roles were not used
Uses ARIA roles only on compatible elements
Image elements do not have `[alt]` attributes that are redundant text.
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
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
`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.
Input buttons have discernible text.
`<input type="image">` elements have `[alt]` text
The document does not use `<meta http-equiv="refresh">`
`<object>` elements have alternate text
Select elements have associated label elements.
Skip links are focusable.
Cells in a `<table>` element that use the `[headers]` attribute refer to table cells within the same table.
`<th>` elements and elements with `[role="columnheader"/"rowheader"]` have data cells they describe.
`<video>` elements contain a `<track>` element with `[kind="captions"]`
Tables have different content in the summary attribute and `<caption>`.
All heading elements contain content.
Tables use `<caption>` instead of cells with the `[colspan]` attribute to indicate a caption.
`<td>` elements in a large `<table>` have one or more table headers.
96

Best Practices

General

Errors logged to the console indicate unresolved problems. They can come from network request failures and other browser concerns. Learn more about this errors in console diagnostic audit

Why this matters

Performance issues directly impact user engagement and conversion rates.

SourceDescription
Failed to load resource: the server responded with a status of 404 ()
Refused to apply style from 'https://partner.schalke04.de/partner/intern/cw_31_2026_Business_Kreisel_LB2/css/normalize.css' because its MIME type ('application/xml') is not a supported stylesheet MIME type, and strict MIME checking is enabled.
Refused to apply style from 'https://partner.schalke04.de/partner/intern/cw_31_2026_Business_Kreisel_LB2/css/normalize.css' because its MIME type ('application/xml') is not a supported stylesheet MIME type, and strict MIME checking is enabled.
Refused to apply style from 'https://partner.schalke04.de/partner/intern/cw_31_2026_Business_Kreisel_LB2/css/normalize.css' because its MIME type ('application/xml') is not a supported stylesheet MIME type, and strict MIME checking is enabled.

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

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 clickjacking with XFO or CSP
Mitigate DOM-based XSS with Trusted Types
Detected JavaScript libraries
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`
Document has a valid `rel=canonical`
robots.txt is valid

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