Lighthouse Mobile

· 0 checks — Mobile 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.

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.

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
www.tuwien.at/resources/fonts/TuWienIcons/tuwien-icons.ttf?1763412710	40 ms

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:359.083 label:Time to first byte subpart:timeToFirstByte] map[duration:2163.158 label:Resource load delay subpart:resourceLoadDelay] map[duration:116.223 label:Resource load duration subpart:resourceLoadDuration] map[duration:23.113 label:Element render delay subpart:elementRenderDelay]]

lhId: page-0-IMG

nodeLabel: Im Hintergrund das Hauptgebäude der TU Wien, im Vordergrund ein buntes Blumenbe…

path: 1,HTML,1,BODY,3,DIV,0,MAIN,1,DIV,0,FIGURE,0,DIV,0,PICTURE,7,IMG

selector: figure.wpBackground > div.wpBackgroundImage > picture > img.landscape

snippet: <img width="1800" height="666" alt="Im Hintergrund das Hauptgebäude der TU Wien, im Vordergrund ein buntes Blu…" data-src="/fileadmin/_processed_/d/3/csm_TU_Wien_Fruelingsbild_Header_2a67b1ebf8.jpg" src="https://www.tuwien.at/fileadmin/_processed_/d/3/csm_TU_Wien_Fruelingsbild_…" class="landscape lazyload-blur lazyloaded">

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: Im Hintergrund das Hauptgebäude der TU Wien, im Vordergrund ein buntes Blumenbe…

path: 1,HTML,1,BODY,3,DIV,0,MAIN,1,DIV,0,FIGURE,0,DIV,0,PICTURE,7,IMG

selector: figure.wpBackground > div.wpBackgroundImage > picture > img.landscape

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
/typo3temp/assets/compressed/merged-d628bb01eaf254b65cc60...	74.3 KiB	450 ms
/_assets/3b1e37ddfca841316c0d227c9c4c4020/Js/lazyload.min...	9.7 KiB
/typo3temp/assets/compressed/merged-4e9768f205972950b49ab...	6.4 KiB
/_assets/f6ef6adaf5c92bf687a31a3adbcb0f7b/Css/news-basic....	1.2 KiB

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
Foto von sechs Personen, die nebeneinander stehen `div.wpItem > figure > picture > img.landscape`	/fileadmin/_processed_/9/1/csm_FDM_Newsserie_FAIR-Kampagn...	241.5 KiB	228.0 KiB
Im Hintergrund das Hauptgebäude der TU Wien, im Vordergrund ein buntes Blumenbe… `figure.wpBackground > div.wpBackgroundImage > picture > img.landscape`	/fileadmin/_processed_/d/3/csm_TU_Wien_Fruelingsbild_Head...	52.8 KiB	38.9 KiB
Darstellung zweier Materialien, die aufeinander positioniert sind, mit Spalt au… `div.wpItem > figure > picture > img.landscape`	www.tuwien.at/fileadmin/_processed_/1/8/csm_Van_der_Waals_Spalt_2871efdfa5.jpg	39.4 KiB	26.0 KiB
Medaillen vom Vienna City Marathon 2026 - im Hintergrund sieht man Himmel, Bäum… `div.wpItem > figure > picture > img.landscape`	www.tuwien.at/fileadmin/_processed_/7/1/csm_vcm2026_cover_f14b0e56d3.jpg	29.7 KiB	17.4 KiB
Zwei Menschen sind von hinten zu sehen. Sie stehen auf dem Dach eines Gebäudes … `div.swiper-wrapper > div.swiper-slide > picture > img.portrait`	/fileadmin/_processed_/8/d/csm_menschen_c_tu_wien_matthia...	35.8 KiB	12.1 KiB

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

Redirects introduce additional delays before the page can be loaded. Learn how to avoid page redirects.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 752 ms

URL	Time Spent
tuwien.ac.at/	752 ms
www.tuwien.at/	0.0 ms

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.

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

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: 300 ms 65.7 KiB

URL	Transfer Size	Est Savings
/typo3temp/assets/compressed/merged-d628bb01eaf254b65cc60...	73.9 KiB	65.7 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: 1.2 s 240.8 KiB

URL	Transfer Size	Est Savings
/_assets/3b1e37ddfca841316c0d227c9c4c4020/mathjax3/tex-ch...	257.7 KiB	125.1 KiB
/typo3temp/assets/compressed/merged-39380130e3fb2cb55ca14...	168.1 KiB	115.7 KiB

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

●Use efficient cache lifetimes

●Layout shift culprits

●Optimize DOM size

●Forced reflow

●Modern HTTP

●Optimize viewport for mobile

●Minify CSS

●Minify JavaScript

●Avoids enormous network payloads Total size was 1,364 KiB

●JavaScript execution time 0.9 s

●Minimizes main-thread work 1.6 s

●Avoid long main-thread tasks 5 long tasks found

●Image elements have explicit `width` and `height`

●Page didn't prevent back/forward cache restoration

●Network Requests

●Network Round Trip Times 40 ms

●Server Backend Latencies 70 ms

●Tasks

●Diagnostics

●Metrics

●Screenshot Thumbnails

●Final Screenshot

●Script Treemap Data

●Resources Summary

●Initial server response time was short Root document took 140 ms

●Avoid large layout shifts 1 layout shift found

○INP breakdown

○User Timing marks and measures

○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

ARIA dialog elements without accessible names may prevent screen readers users from discerning the purpose of these elements. Learn how to make ARIA dialog elements more accessible.

Why this matters

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

Source: MDN Permissions-Policy

Failing Elements
Hinweis zu Cookies und anderen Techniken × Unsere Website verwendet Cookies un… `body.mm-wrapper > div#cookieman-modal`

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.

○Interactive controls are keyboard focusable

○Interactive elements indicate their purpose and state

○The page has a logical tab order

○Visual order on the page follows DOM order

○User focus is not accidentally trapped in a region

○The user's focus is directed to new content added to the page

○HTML5 landmark elements are used to improve navigation

○Offscreen content is hidden from assistive technology

○Custom controls have associated labels

○Custom controls have ARIA roles

●`[aria-*]` attributes match their roles

●`[aria-hidden="true"]` is not present on the document `<body>`

●`[role]`s have all required `[aria-*]` attributes

●Elements with an ARIA `[role]` that require children to contain a specific `[role]` have all required children.

●`[role]`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.

●`[accesskey]` values are unique

●ARIA attributes are used as specified for the element's role

●`[aria-hidden="true"]` elements do not contain focusable descendents

●Elements use only permitted ARIA attributes

●Background and foreground colors have a sufficient contrast ratio

●Document has a `<title>` element

●`<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

●Skip links are focusable.

●Document has a main landmark.

●Deprecated ARIA roles were not used

●Uses ARIA roles only on compatible elements

●Elements with visible text labels have matching accessible names.

○`button`, `link`, and `menuitem` elements have accessible names

○ARIA input fields 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 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

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

○`<object>` elements have alternate text

○Select elements have associated label elements.

○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.

○Image elements do not have `[alt]` attributes that are redundant text.

○Identical links have the same purpose.

○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

Source	Description
/typo3temp/assets/compressed/merged-4e9768f205972950b49ab... line 18, col 1080	TypeError: Cannot convert undefined or null to object at Object.entries (<anonymous>) at https://www.tuwien.at/typo3temp/assets/compressed/merged-4e9768f205972950b49abcf8b057b514-13870e0375ddc0f728881ee62fdc772c.js?1741602688:19:1081 at https://www.tuwien.at/typo3temp/assets/compressed/merged-4e9768f205972950b49abcf8b057b514-13870e0375ddc0f728881ee62fdc772c.js?1741602688:19:1730 at https://www.tuwien.at/typo3temp/assets/compressed/merged-4e9768f205972950b49abcf8b057b514-13870e0375ddc0f728881ee62fdc772c.js?1741602688:19:8463

/typo3temp/assets/compressed/merged-4e9768f205972950b49ab... line 18, col 1080

TypeError: Cannot convert undefined or null to object
    at Object.entries (<anonymous>)
    at https://www.tuwien.at/typo3temp/assets/compressed/merged-4e9768f205972950b49abcf8b057b514-13870e0375ddc0f728881ee62fdc772c.js?1741602688:19:1081
    at https://www.tuwien.at/typo3temp/assets/compressed/merged-4e9768f205972950b49abcf8b057b514-13870e0375ddc0f728881ee62fdc772c.js?1741602688:19:1730
    at https://www.tuwien.at/typo3temp/assets/compressed/merged-4e9768f205972950b49abcf8b057b514-13870e0375ddc0f728881ee62fdc772c.js?1741602688:19:8463

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
/typo3temp/assets/compressed/merged-39380130e3fb2cb55ca14...	www.tuwien.at/typo3temp/assets/compressed/scripts.min.js.map
/_assets/3b1e37ddfca841316c0d227c9c4c4020/mathjax3/tex-ch...
/_assets/3b1e37ddfca841316c0d227c9c4c4020/Js/lazyload.min...	www.tuwien.at/_assets/3b1e37ddfca841316c0d227c9c4c4020/Js/lazyload.min.js.map

●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`