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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.

62

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:0.209841] map[node:map[boundingRect:map[bottom:536 height:251 left:16 right:396 top:285 width:380] lhId:page-20-SECTION nodeLabel:¡Inscríbete! Prevención de Riesgos Laborales path:1,HTML,1,BODY,4,MAIN,0,DIV,1,SECTION selector:body.didomi-popup-open > main#portada > div.news-flex > section#subzona_2_1 snippet:<section id="subzona_2_1" class="news2"> type:node] score:0.192358 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:269 height:204 left:0 right:412 top:65 width:412] lhId:page-2-IMG nodeLabel:¡Un sábado de matemáticas y talento! Casi 4.000 jóvenes -de entre 10 y 17 años … path:1,HTML,1,BODY,4,MAIN,0,DIV,0,SECTION,0,DIV,0,DIV,1,ARTICLE,0,FIGURE,0,A,0,IMG selector:article.item > figure.n_img > a > img snippet:<img src="https://www.ucm.es/ext/apps/file/news/concurso-primavera-matematicas-2026/…" alt="¡Un sábado de matemáticas y talento! Casi 4.000 jóvenes -de entre 10 y 17 …" loading="lazy"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:625 height:427 left:0 right:412 top:198 width:412] lhId:page-24-DIV nodeLabel:In our web pages we use cookies and other similar technologies of our own and o… path:1,HTML,1,BODY,1,DIV,0,DIV,0,DIV,1,DIV selector:div#didomi-host > div.notranslate > div#didomi-popup > div.didomi-exterior-border snippet:<div class="didomi-exterior-border didomi-popup__exterior-border"> type:node] score:0.016154 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:282 height:51 left:106 right:306 top:231 width:200] lhId:page-16-IMG nodeLabel:Logo path:1,HTML,1,BODY,1,DIV,0,DIV,0,DIV,1,DIV,0,DIV,1,DIV,0,DIV,0,IMG selector:div.didomi-popup-container > div.didomi-popup-view > div.didomi-popup-notice-logo-container > img.didomi-popup-notice-logo snippet:<img class="didomi-popup-notice-logo" alt="Logo" src="https://www.ucm.es/themes/ucm16/media/img/logo.png" role="heading" aria-level="1"> type:node]]] type:subitems]] map[node:map[boundingRect:map[bottom:269 height:114 left:0 right:412 top:154 width:412] lhId:page-18-DIV nodeLabel:¡Un sábado de matemáticas y talento! Casi 4.000 jóvenes -de entre 10 y 17 años … path:1,HTML,1,BODY,4,MAIN,0,DIV,0,SECTION,0,DIV,0,DIV,1,ARTICLE,1,DIV selector:div#carouselUcm > div.carousel-inner > article.item > div.news1_txt snippet:<div class="news1_txt carousel-caption-ucm"> type:node] score:0.001329 subItems:map[items:[map[cause:Unsized image element extra:map[boundingRect:map[bottom:857 height:20 left:195 right:337 top:837 width:142] lhId:page-17-IMG nodeLabel:UCM Directo path:1,HTML,1,BODY,4,MAIN,1,DIV,1,SECTION,0,HEADER,1,A,0,IMG selector:section#eventos > header > a > img snippet:<img src="/themes/ucm24/media/img/ucm-directo.png" alt="UCM Directo" loading="lazy"> type:node]]] type:subitems]]]

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
Competiciones deportivas article > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/competiciones/?ver=495.1 KiB440.7 KiB
li > div.evento > figure > img li > div.evento > figure > img
eventos.ucm.es/_files/_event/_152868/_header_img/_229233.png397.5 KiB386.5 KiB
¡Un sábado de matemáticas y talento! Casi 4.000 jóvenes -de entre 10 y 17 años … article.item > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/concurso-primavera-matematicas-2026/?ver=n288.1 KiB246.3 KiB
li > div.evento > figure > img li > div.evento > figure > img
eventos.ucm.es/_files/_event/_152798/_header_img/_229128.png250.8 KiB240.4 KiB
li > div.evento > figure > img li > div.evento > figure > img
eventos.ucm.es/_files/_event/_149996/_header_img/_224396.png127.5 KiB117.3 KiB
Complutense Saludable article > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/download/?ver=m75.2 KiB71.1 KiB
Deporte UCM article > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/deporte-2/?ver=m61.6 KiB58.9 KiB
HR Excellence in Research ul > li > a > img
ucm.es/themes/ucm24/media/img/hrs4r.png57.0 KiB56.7 KiB
¡Inscríbete! article > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/jornadas-para-familias-2026-pequena/?ver=m50.4 KiB43.6 KiB
Unidad de Cultura Científica UCM article > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/foto-portada-ucm-259-x-175-px/?ver=m46.2 KiB43.0 KiB
Cultura Complutense article > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/osucm-navidad23-006/?ver=m44.7 KiB42.0 KiB
Consulta de resultados provisionales article > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/elecciones-claustro26/?ver=m46.9 KiB40.2 KiB
Fundación Complutense article > figure.n_img > a > img
/ext/apps/file/news/imagen-página-web-miniatura-ucmweb-...42.3 KiB38.0 KiB
Investigación UCM article > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/investigacion/?ver=m40.7 KiB37.9 KiB
Prevención de Riesgos Laborales article > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/web-bn-pq-prl-01-262x200/?ver=m38.7 KiB32.0 KiB
Elecciones 2026: procesos en curso article > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/2claustro-universitario26/?ver=m34.1 KiB27.3 KiB
Logo div.didomi-popup-container > div.didomi-popup-view > div.didomi-popup-notice-logo-container > img.didomi-popup-notice-logo
www.ucm.es/themes/ucm16/media/img/logo.png21.8 KiB17.5 KiB
UCM Directo section#eventos > header > a > img
ucm.es/themes/ucm24/media/img/ucm-directo.png13.3 KiB12.4 KiB

Optimize LCP by making the LCP image discoverable from the HTML immediately, and avoiding lazy-loading

Why this matters

Performance issues directly impact user engagement and conversion rates.

lhId: page-2-IMG
nodeLabel: ¡Un sábado de matemáticas y talento! Casi 4.000 jóvenes -de entre 10 y 17 años …
path: 1,HTML,1,BODY,4,MAIN,0,DIV,0,SECTION,0,DIV,0,DIV,1,ARTICLE,0,FIGURE,0,A,0,IMG
selector: article.item > figure.n_img > a > img
snippet: <img src="https://www.ucm.es/ext/apps/file/news/concurso-primavera-matematicas-2026/…" alt="¡Un sábado de matemáticas y talento! Casi 4.000 jóvenes -de entre 10 y 17 …" loading="lazy">

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
ucm.es/http/1.1
ucm.es/themes/ucm24/css/bootstrap.csshttp/1.1
ucm.es/themes/ucm24/css/font-awesome.min.csshttp/1.1
ucm.es/themes/ucm24/css/ucm-theme.css?ft=20260421140505http/1.1
ucm.es/themes/ucm24/css/ucm.css?ft=20260421140505http/1.1
ucm.es/themes/ucm24/css/ucm-wg.css?ft=20260421140505http/1.1
ucm.es/themes/ucm24/css/ucm_home.css?ft=20260421140505http/1.1
ucm.es/themes/ucm24/css/menu_3.css?ft=20260421140504http/1.1
ucm.es/themes/ucm24/media/img/logo.svghttp/1.1
ucm.es/themes/ucm24/media/img/banderas/en.pnghttp/1.1
ucm.es/themes/ucm24/media/img/youtube.svghttp/1.1
ucm.es/themes/ucm24/media/img/facebook.svghttp/1.1
ucm.es/themes/ucm24/media/img/x.svghttp/1.1
ucm.es/themes/ucm24/media/img/linkedin.svghttp/1.1
ucm.es/themes/ucm24/media/img/instagram.svghttp/1.1
ucm.es/themes/ucm24/media/img/tiktok.svghttp/1.1
ucm.es/themes/ucm24/media/img/bluesky.svghttp/1.1
ucm.es/themes/ucm24/media/img/hrs4r.pnghttp/1.1
ucm.es/themes/ucm24/media/img/una-europa.svghttp/1.1
ucm.es/themes/ucm24/media/img/ucrania.pnghttp/1.1
ucm.es/themes/ucm24/js/jquery.min.jshttp/1.1
ucm.es/themes/ucm24/js/bootstrap.jshttp/1.1
ucm.es/themes/ucm24/js/ucm.js?ft=20260421140505http/1.1
ucm.es/themes/ucm24/js/ucm_carousel.js?ft=20260421140505http/1.1
ucm.es/themes/ucm24/css/print.css?ft=20260421140505http/1.1
ucm.es/themes/ucm24/fonts/Roboto-Regular.ttfhttp/1.1
ucm.es/themes/ucm24/fonts/fontawesome-webfont.woff2?v=4.7.0http/1.1
www.ucm.es/ext/apps/file/news/concurso-primavera-matematicas-2026/?ver=nhttp/1.1
www.ucm.es/ext/apps/file/news/jornadas-para-familias-2026-pequena/?ver=mhttp/1.1
www.ucm.es/ext/apps/file/news/web-bn-pq-prl-01-262x200/?ver=mhttp/1.1
www.ucm.es/ext/apps/file/news/2claustro-universitario26/?ver=mhttp/1.1
www.ucm.es/ext/apps/file/news/elecciones-claustro26/?ver=mhttp/1.1
ucm.es/themes/ucm24/media/img/ucm-tribuna-complutense.svghttp/1.1
ucm.es/themes/ucm24/media/img/ucm-directo.pnghttp/1.1
www.ucm.es/ext/apps/file/news/osucm-navidad23-006/?ver=mhttp/1.1
www.ucm.es/ext/apps/file/news/investigacion/?ver=mhttp/1.1
www.ucm.es/ext/apps/file/news/deporte-2/?ver=mhttp/1.1
ucm.es/themes/ucm24/media/img/iconos/ucm-informacion.svghttp/1.1
ucm.es/themes/ucm24/media/img/iconos/ucm-transparencia.svghttp/1.1
ucm.es/themes/ucm24/media/img/iconos/ucm-sede-electronica.svghttp/1.1
ucm.es/themes/ucm24/media/img/iconos/ucm-becas-y-ayudas.svghttp/1.1
ucm.es/themes/ucm24/media/img/iconos/ucm-perfil-del-contratante.svghttp/1.1
ucm.es/themes/ucm24/media/img/iconos/ucm-biblioteca.svghttp/1.1
ucm.es/themes/ucm24/media/img/iconos/ucm-campus-virtual.svghttp/1.1
ucm.es/themes/ucm24/media/img/iconos/ucm-online.svghttp/1.1
www.ucm.es/ext/apps/file/news/competiciones/?ver=http/1.1
www.ucm.es/ext/apps/file/news/foto-portada-ucm-259-x-175-px/?ver=mhttp/1.1
www.ucm.es/ext/apps/file/news/download/?ver=mhttp/1.1
/ext/apps/file/news/imagen-página-web-miniatura-ucmweb-...http/1.1
www.ucm.es/themes/ucm16/media/img/logo.pnghttp/1.1
ucm.es/themes/ucm24/media/img/logoucm.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
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.

URLTransfer SizeDuration
ucm.es/themes/ucm24/css/ucm_home.css?ft=202604211405055.8 KiB606 ms
ucm.es/themes/ucm24/css/menu_3.css?ft=202604211405042.0 KiB155 ms
ucm.es/themes/ucm24/css/ucm-wg.css?ft=2026042114050512.0 KiB756 ms
ucm.es/themes/ucm24/css/ucm.css?ft=202604211405056.7 KiB606 ms
ucm.es/themes/ucm24/css/ucm-theme.css?ft=202604211405052.2 KiB455 ms
ucm.es/themes/ucm24/css/font-awesome.min.css9.3 KiB756 ms
ucm.es/themes/ucm24/css/bootstrap.css32.8 KiB907 ms

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
/dc628592-8975-46a5-82c3-2fb34d165e56/loader.js?target=uc...7200.0 s29.7 KiB

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
ucm.es/themes/ucm24/fonts/Roboto-Regular.ttf15 ms
ucm.es/themes/ucm24/fonts/fontawesome-webfont.woff2?v=4.7.015 ms

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

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
¡Inscríbete! Prevención de Riesgos Laborales body.didomi-popup-open > main#portada > div.news-flex > section#subzona_2_1
0.192
In our web pages we use cookies and other similar technologies of our own and o… div#didomi-host > div.notranslate > div#didomi-popup > div.didomi-exterior-border
0.016
¡Un sábado de matemáticas y talento! Casi 4.000 jóvenes -de entre 10 y 17 años … div#carouselUcm > div.carousel-inner > article.item > div.news1_txt
0.001

Time to Interactive is the amount of time it takes for the page to become fully interactive. Learn more about the Time to Interactive metric.

Why this matters

Performance issues directly impact user engagement and conversion rates.

TTI

The maximum potential First Input Delay that your users could experience is the duration of the longest task. Learn more about the Maximum Potential First Input Delay metric.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Diagnostics

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: 150 ms 56.3 KiB
URLTransfer SizeEst Savings
ucm.es/themes/ucm24/css/bootstrap.css32.4 KiB30.6 KiB
16.6 KiB14.2 KiB
ucm.es/themes/ucm24/css/ucm-wg.css?ft=2026042114050511.5 KiB11.5 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: 150 ms 208.7 KiB
URLTransfer SizeEst Savings
www.googletagmanager.com/gtag/js?id=G-65GWBF2XN6&cx=c&gtm=4e64h1155.5 KiB66.9 KiB
www.googletagmanager.com/gtag/js?id=G-6XY0QFTRLR157.7 KiB63.5 KiB
/sdk/22ecd6bfac93de604efec0b75b2c796ee1675f92/modern/sdk....101.3 KiB54.5 KiB
ucm.es/themes/ucm24/js/jquery.min.js40.4 KiB23.8 KiB

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 with cache-control:no-store header cannot enter back/forward cache.Actionable
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 CSS files can reduce network payload sizes. Learn how to minify CSS.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 0.0 ms 8.0 KiB
URLTransfer SizeEst Savings
ucm.es/themes/ucm24/css/bootstrap.css32.8 KiB5.5 KiB
ucm.es/themes/ucm24/css/ucm-wg.css?ft=2026042114050512.0 KiB2.5 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 7.3 KiB
URLTransfer SizeEst Savings
ucm.es/themes/ucm24/js/bootstrap.js21.3 KiB7.3 KiB

Large network payloads cost users real money and are highly correlated with long load times. Learn how to reduce payload sizes.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLTransfer Size
www.ucm.es/ext/apps/file/news/competiciones/?ver=495.4 KiB
eventos.ucm.es/_files/_event/_152868/_header_img/_229233.png398.2 KiB
eventos.ucm.es/_files/_event/_152137/_header_img/_228735.png393.7 KiB
eventos.ucm.es/_files/_event/_152899/_header_img/_229286.png386.9 KiB
www.ucm.es/ext/apps/file/news/concurso-primavera-matematicas-2026/?ver=n288.4 KiB
eventos.ucm.es/_files/_event/_152798/_header_img/_229128.png251.3 KiB
eventos.ucm.es/_files/_event/_152086/_header_img/_228385.jpe193.3 KiB
eventos.ucm.es/_files/_event/_152873/_header_img/_229280.jpe182.4 KiB
eventos.ucm.es/_files/_event/_152877/_header_img/_229278.jpe182.4 KiB
www.googletagmanager.com/gtag/js?id=G-6XY0QFTRLR158.0 KiB

Set an explicit width and height on image elements to reduce layout shifts and improve CLS. Learn how to set image dimensions

Why this matters

Performance issues directly impact user engagement and conversion rates.

URL
HR Excellence in Research ul > li > a > img
ucm.es/themes/ucm24/media/img/hrs4r.png
ul.di_bloque1 > li > a > img ul.di_bloque1 > li > a > img
ucm.es/themes/ucm24/media/img/iconos/ucm-informacion.svg
ul.di_bloque1 > li > a > img ul.di_bloque1 > li > a > img
ucm.es/themes/ucm24/media/img/iconos/ucm-transparencia.svg
ul.di_bloque1 > li > a > img ul.di_bloque1 > li > a > img
ucm.es/themes/ucm24/media/img/iconos/ucm-sede-electronica.svg
ul.di_bloque1 > li > a > img ul.di_bloque1 > li > a > img
ucm.es/themes/ucm24/media/img/iconos/ucm-becas-y-ayudas.svg
ul.di_bloque1 > li > a > img ul.di_bloque1 > li > a > img
ucm.es/themes/ucm24/media/img/iconos/ucm-perfil-del-contratante.svg
ul.di_bloque1 > li > a > img ul.di_bloque1 > li > a > img
ucm.es/themes/ucm24/media/img/iconos/ucm-biblioteca.svg
ul.di_bloque2 > li > a > img ul.di_bloque2 > li > a > img
ucm.es/themes/ucm24/media/img/iconos/ucm-campus-virtual.svg
ul.di_bloque2 > li > a > img ul.di_bloque2 > li > a > img
ucm.es/themes/ucm24/media/img/iconos/ucm-online.svg
¡Un sábado de matemáticas y talento! Casi 4.000 jóvenes -de entre 10 y 17 años … article.item > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/concurso-primavera-matematicas-2026/?ver=n
Consulta de resultados provisionales article > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/elecciones-claustro26/?ver=m
Elecciones 2026: procesos en curso article > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/2claustro-universitario26/?ver=m
¡Inscríbete! article > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/jornadas-para-familias-2026-pequena/?ver=m
Prevención de Riesgos Laborales article > figure.n_img > a > img
www.ucm.es/ext/apps/file/news/web-bn-pq-prl-01-262x200/?ver=m
Universidad Complutense de Madrid div#cabecera > div#logo > a > img
ucm.es/themes/ucm24/media/img/logo.svg
Logo div.didomi-popup-container > div.didomi-popup-view > div.didomi-popup-notice-logo-container > img.didomi-popup-notice-logo
www.ucm.es/themes/ucm16/media/img/logo.png
Una Europa ul > li > a > img
ucm.es/themes/ucm24/media/img/una-europa.svg
Universidades Españolas con Ucrania ul > li > a > img
ucm.es/themes/ucm24/media/img/ucrania.png
Tribuna Complutense ul.enlaces-noticias > li > a > img
ucm.es/themes/ucm24/media/img/ucm-tribuna-complutense.svg

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

●Document request latency
●Optimize DOM size
●Forced reflow
●LCP breakdown
●Optimize viewport for mobile
●User Timing marks and measures 13 user timings
●JavaScript execution time 0.8 s
●Minimizes main-thread work 1.7 s
●Avoid long main-thread tasks 7 long tasks found
●Network Requests
●Network Round Trip Times 30 ms
●Server Backend Latencies 80 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 40 ms
○INP breakdown
○Avoid non-composited animations
88

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
¡Un sábado de matemáticas y talento! Casi 4.000 jóvenes -de entre 10 y 17 años … div.news-flex > section#zona_1_3 > div#carouselUcm > div.carousel-inner

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
¡Un sábado de matemáticas y talento! Casi 4.000 jóvenes -de entre 10 y 17 años … div.news-flex > section#zona_1_3 > div#carouselUcm > div.carousel-inner

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.

Navigation

Properly ordered headings that do not skip levels convey the semantic structure of the page, making it easier to navigate and understand when using assistive technologies. Learn more about heading order.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Failing Elements
¡Un sábado de matemáticas y talento! Casi 4.000 jóvenes -de entre 10 y 17 años … div.carousel-inner > article.item > div.news1_txt > h3

These are opportunities to improve keyboard navigation in your application.

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
Defensora Universitaria li > ul > li > a
Inspección de Servicios li > ul > li > a
Fundación General nav#pie_1 > ul > li#75 > a
Universia España nav#pie_1 > ul > li#12 > a
Empleo UCM nav#pie_1 > ul > li#175 > a
Alquiler de espacios nav#pie_1 > ul > li#1206 > a
Parque Científico nav#pie_1 > ul > li#3197 > a
Sugerencias y Quejas nav#pie_1 > ul > li#1361 > a
Localización y contacto nav#pie_contacto > ul > li > a
Aviso Legal nav#pie_contacto > ul > li > a
Protección de datos nav#pie_contacto > ul > li > a
RSS nav#pie_contacto > ul > li > a

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 with `role="dialog"` or `role="alertdialog"` have accessible names.
●`[aria-hidden="true"]` elements do not contain focusable descendents
●Elements use only permitted ARIA attributes
●Background and foreground colors have a sufficient contrast ratio
●Document has a `<title>` element
●`<html>` element has a `[lang]` attribute
●`<html>` element has a valid value for its `[lang]` attribute
●Links are distinguishable without relying on color.
●Links have a discernible name
●Lists contain only `<li>` elements and script supporting elements (`<script>` and `<template>`).
●List items (`<li>`) are contained within `<ul>`, `<ol>` or `<menu>` parent elements
●No element has a `[tabindex]` value greater than 0
●`[lang]` attributes have a valid value
●Document has a main landmark.
●Deprecated ARIA roles were not used
●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.
○`[accesskey]` values are unique
○`button`, `link`, and `menuitem` elements 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
○`<html>` element has an `[xml:lang]` attribute with the same base language as the `[lang]` attribute.
○Input buttons have discernible text.
○`<input type="image">` elements have `[alt]` text
○Form elements have associated labels
○The document does not use `<meta http-equiv="refresh">`
○`<object>` elements have alternate text
○Select elements have associated label elements.
○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>`.
○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.
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Best Practices

User Experience

Image display dimensions should match natural aspect ratio. Learn more about image aspect ratio.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLAspect Ratio (Displayed)Aspect Ratio (Actual)
English ul#lg_items > li > a > img
ucm.es/themes/ucm24/media/img/banderas/en.png20 x 20 (1.00)30 x 20 (1.50)

Image natural dimensions should be proportional to the display size and the pixel ratio to maximize image clarity. Learn how to provide responsive images.

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLDisplayed sizeActual sizeExpected size
English ul#lg_items > li > a > img
ucm.es/themes/ucm24/media/img/banderas/en.png20 x 2030 x 2030 x 30
●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
●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
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SEO

These checks ensure that your page is following basic search engine optimization advice. There are many additional factors Lighthouse does not score here that may affect your search ranking, including performance on Core Web Vitals. Learn more about Google Search Essentials.

Crawling and Indexing

Search engines may use `href` attributes on links to crawl websites. Ensure that the `href` attribute of anchor elements links to an appropriate destination, so more pages of the site can be discovered. Learn how to make links crawlable

Why this matters

Performance issues directly impact user engagement and conversion rates.

Uncrawlable Link
main#portada > div.news-plus > section#eventos > a.ev-left main#portada > div.news-plus > section#eventos > a.ev-left
main#portada > div.news-plus > section#eventos > a.ev-right main#portada > div.news-plus > section#eventos > a.ev-right

To appear in search results, crawlers need access to your app.

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

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