Skip to content
https://centos.org

Lighthouse Mobile

· 0 checks — Mobile Lighthouse audit -- Performance, Accessibility, Best Practices, and SEO category breakdown.
SCORE
0
GRADE
FIX
0
REVIEW
0
PASS
0
INFO
0

Detailed Report

Audit breakdown by category with detailed findings.

60

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
www.centos.org/assets/img/centos-motif.png0.0 ms1.5 MiB
www.centos.org/assets/css/base/stylesheet.min.css0.0 ms295.7 KiB
www.centos.org/assets/js/bootstrap.bundle.min.js0.0 ms79.3 KiB
www.centos.org/assets/img/sponsors/serverpronto_small.gif0.0 ms65.6 KiB
www.centos.org/assets/img/sponsors/vhostvn.gif0.0 ms32.8 KiB
www.centos.org/assets/img/sponsors/shinjirubanner260x60.gif0.0 ms23.6 KiB
www.centos.org/assets/img/sponsors/servermania.gif0.0 ms21.8 KiB
www.centos.org/assets/img/sponsors/PNAP_Banner.gif0.0 ms18.1 KiB
www.centos.org/assets/img/sponsors/server-net.png0.0 ms16.9 KiB
www.centos.org/assets/img/sponsors/eukhost.png0.0 ms15.2 KiB
img.youtube.com/vi/neWBY0KwW_Y/hqdefault.jpg7200.0 s18.9 KiB
www.centos.org/assets/img/sponsors/itsyndicate.png0.0 ms13.7 KiB
img.youtube.com/vi/ayMpLYBOViQ/hqdefault.jpg7200.0 s17.6 KiB
img.youtube.com/vi/-osWEQVvedg/hqdefault.jpg7200.0 s17.4 KiB
www.centos.org/assets/img/sponsors/wowrack.png0.0 ms12.3 KiB
www.centos.org/assets/img/sponsors/whitelabelitsolutions.gif0.0 ms11.8 KiB
www.centos.org/assets/img/sponsors/hostiserver.png0.0 ms11.2 KiB
www.centos.org/assets/img/sponsors/colocation-america.png0.0 ms10.5 KiB
www.centos.org/assets/img/sponsors/cdn77.png0.0 ms9.6 KiB
www.centos.org/assets/img/sponsors/host-stage.png0.0 ms9.5 KiB
www.centos.org/assets/img/sponsors/webnx1.png0.0 ms9.1 KiB
www.centos.org/assets/img/sponsors/multacom-240x60.gif0.0 ms8.9 KiB
www.centos.org/assets/img/sponsors/lyrahosting.png0.0 ms8.6 KiB
www.centos.org/assets/img/sponsors/serverpoint.png0.0 ms8.4 KiB
www.centos.org/assets/img/sponsors/baseip_240x60.jpg0.0 ms8.0 KiB
www.centos.org/assets/img/sponsors/introserv.png0.0 ms7.7 KiB
www.centos.org/assets/img/sponsors/centos-serverhub.png0.0 ms7.7 KiB
www.centos.org/assets/img/sponsors/GameHost.png0.0 ms6.8 KiB
www.centos.org/assets/img/sponsors/am-logo.png0.0 ms6.3 KiB
www.centos.org/assets/img/sponsors/wehaveservers.png0.0 ms6.1 KiB
www.centos.org/assets/img/sponsors/altushost.png0.0 ms6.1 KiB
www.centos.org/assets/img/sponsors/hostkey.png0.0 ms5.7 KiB
www.centos.org/assets/img/sponsors/fasthosts.png0.0 ms5.7 KiB
www.centos.org/assets/img/sponsors/NDCHost.png0.0 ms5.3 KiB
www.centos.org/assets/img/sponsors/serverel.png0.0 ms5.1 KiB
www.centos.org/assets/img/sponsors/aws.png0.0 ms4.9 KiB
www.centos.org/assets/img/sponsors/dedicatedsolutions.png0.0 ms4.4 KiB
www.centos.org/assets/img/sponsors/binaryracks.png0.0 ms4.3 KiB
www.centos.org/assets/img/sponsors/trabia.png0.0 ms4.3 KiB
www.centos.org/assets/img/centos-whitelogo.svg0.0 ms4.0 KiB
www.centos.org/assets/img/sponsors/unihost.png0.0 ms3.8 KiB
www.centos.org/assets/img/sponsors/vsys.png0.0 ms3.5 KiB
www.centos.org/assets/img/sponsors/vultr.png0.0 ms3.1 KiB
www.centos.org/assets/img/sponsors/internetx.gif0.0 ms3.0 KiB
www.centos.org/assets/img/centos-symbol.svg0.0 ms2.1 KiB
www.centos.org/assets/img/sponsors/stablepoint.png0.0 ms1.7 KiB
www.centos.org/assets/img/sponsors/clientvps.png0.0 ms1.4 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.

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:Source valueType:source-location] map[granularity:1 key:reflowTime label:Total reflow time valueType:ms]]
items: [map[reflowTime:37.022 source:map[column:2323 line:0 type:source-location url:https://unpkg.com/vanilla-back-to-top@7.2.1/dist/vanilla-back-to-top.min.js urlProvider:network]]]

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

URLResource SizeEst Savings
Community-driven free software effort focused around the goal of providing a ri… body#top > footer.footer
www.centos.org/assets/img/centos-motif.png1.5 MiB1.1 MiB
Inside the RHEL 11 Planning Room: How Fedora and Stream Shape the Next Enterpri… div.row > div.col-sm-4 > div.card > img.card-img-top
img.youtube.com/vi/neWBY0KwW_Y/hqdefault.jpg18.8 KiB6.6 KiB
PTE: What’s coming up in Copr, TestingFarm, tmt, Packit and LogDetective div.row > div.col-sm-4 > div.card > img.card-img-top
img.youtube.com/vi/ayMpLYBOViQ/hqdefault.jpg17.5 KiB6.2 KiB
Cutting the Gordian Knot of Kernel Packaging: A Refactoring Proposal div.row > div.col-sm-4 > div.card > img.card-img-top
img.youtube.com/vi/-osWEQVvedg/hqdefault.jpg16.9 KiB6.0 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-4-DIV
nodeLabel: The CentOS Project Community-driven free software effort focused on delivering …
path: 1,HTML,1,BODY,1,MAIN,0,DIV
selector: body#top > main.container > div.d-flex
snippet: <div class="d-flex justify-content-center bg-dark bg-image text-bg-dark py-5 px-sm-5">

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
www.centos.org/assets/css/base/stylesheet.min.csshttp/1.1
www.centos.org/assets/img/centos-whitelogo.svghttp/1.1
www.centos.org/assets/img/centos-symbol.svghttp/1.1
www.centos.org/site.webmanifesthttp/1.1
www.centos.org/assets/img/sponsors/altushost.pnghttp/1.1
www.centos.org/assets/img/sponsors/am-logo.pnghttp/1.1
www.centos.org/assets/img/sponsors/aws.pnghttp/1.1
www.centos.org/assets/img/sponsors/baseip_240x60.jpghttp/1.1
www.centos.org/assets/img/sponsors/binaryracks.pnghttp/1.1
www.centos.org/assets/img/sponsors/cdn77.pnghttp/1.1
www.centos.org/assets/img/sponsors/clientvps.pnghttp/1.1
www.centos.org/assets/img/sponsors/colocation-america.pnghttp/1.1
www.centos.org/assets/img/sponsors/dedicatedsolutions.pnghttp/1.1
www.centos.org/assets/img/sponsors/eukhost.pnghttp/1.1
www.centos.org/assets/img/sponsors/fasthosts.pnghttp/1.1
www.centos.org/assets/img/sponsors/GameHost.pnghttp/1.1
www.centos.org/assets/img/sponsors/hostiserver.pnghttp/1.1
www.centos.org/assets/img/sponsors/hostkey.pnghttp/1.1
www.centos.org/assets/img/sponsors/host-stage.pnghttp/1.1
www.centos.org/assets/img/sponsors/internetx.gifhttp/1.1
www.centos.org/assets/img/sponsors/introserv.pnghttp/1.1
www.centos.org/assets/img/sponsors/itsyndicate.pnghttp/1.1
www.centos.org/assets/img/sponsors/lyrahosting.pnghttp/1.1
www.centos.org/assets/img/sponsors/multacom-240x60.gifhttp/1.1
www.centos.org/assets/img/sponsors/NDCHost.pnghttp/1.1
www.centos.org/assets/img/sponsors/PNAP_Banner.gifhttp/1.1
www.centos.org/assets/img/sponsors/server-net.pnghttp/1.1
www.centos.org/assets/img/sponsors/serverel.pnghttp/1.1
www.centos.org/assets/img/sponsors/centos-serverhub.pnghttp/1.1
www.centos.org/assets/img/sponsors/servermania.gifhttp/1.1
www.centos.org/assets/img/sponsors/serverpoint.pnghttp/1.1
www.centos.org/assets/img/sponsors/serverpronto_small.gifhttp/1.1
www.centos.org/assets/img/sponsors/shinjirubanner260x60.gifhttp/1.1
www.centos.org/assets/img/sponsors/stablepoint.pnghttp/1.1
www.centos.org/assets/img/sponsors/trabia.pnghttp/1.1
www.centos.org/assets/img/sponsors/unihost.pnghttp/1.1
www.centos.org/assets/img/sponsors/vhostvn.gifhttp/1.1
www.centos.org/assets/img/sponsors/vsys.pnghttp/1.1
www.centos.org/assets/img/sponsors/vultr.pnghttp/1.1
www.centos.org/assets/img/sponsors/webnx1.pnghttp/1.1
www.centos.org/assets/img/sponsors/wehaveservers.pnghttp/1.1
www.centos.org/assets/img/sponsors/whitelabelitsolutions.gifhttp/1.1
www.centos.org/assets/img/sponsors/wowrack.pnghttp/1.1
www.centos.org/assets/js/bootstrap.bundle.min.jshttp/1.1
www.centos.org/assets/img/centos-motif.pnghttp/1.1
www.centos.org/assets/icons/favicon.svghttp/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
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.

Your first network request is the most important. Reduce its latency by avoiding redirects, ensuring a fast server response, and enabling text compression.

Why this matters

Performance issues directly impact user engagement and conversion rates.

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

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

TTI

Diagnostics

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: 170 ms 50.7 KiB
URLTransfer SizeEst Savings
www.centos.org/assets/css/base/stylesheet.min.css295.7 KiB50.7 KiB

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

Why this matters

Performance issues directly impact user engagement and conversion rates.

Estimated savings: 1.5 s 298.2 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: 340 ms 61.2 KiB
URLTransfer SizeEst Savings
www.centos.org/assets/js/bootstrap.bundle.min.js78.8 KiB61.2 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
Inside the RHEL 11 Planning Room: How Fedora and Stream Shape the Next Enterpri… div.row > div.col-sm-4 > div.card > img.card-img-top
img.youtube.com/vi/neWBY0KwW_Y/hqdefault.jpg
Cutting the Gordian Knot of Kernel Packaging: A Refactoring Proposal div.row > div.col-sm-4 > div.card > img.card-img-top
img.youtube.com/vi/-osWEQVvedg/hqdefault.jpg
PTE: What’s coming up in Copr, TestingFarm, tmt, Packit and LogDetective div.row > div.col-sm-4 > div.card > img.card-img-top
img.youtube.com/vi/ayMpLYBOViQ/hqdefault.jpg
The CentOS Project nav.navbar > div.container > a.navbar-brand > img
www.centos.org/assets/img/centos-whitelogo.svg
CentOS div.d-flex > div.col-sm-12 > div.mb-5 > img
www.centos.org/assets/img/centos-symbol.svg
AltusHost div.carousel-item > div.d-flex > a > img
www.centos.org/assets/img/sponsors/altushost.png

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

●Layout shift culprits
●Optimize DOM size
●LCP breakdown
●Optimize viewport for mobile
●Max Potential First Input Delay 20 ms
●Minify JavaScript
●JavaScript execution time 0.1 s
●Minimizes main-thread work 0.8 s
●Avoid long main-thread tasks 2 long tasks found
●Page didn't prevent back/forward cache restoration
●Network Requests
●Network Round Trip Times 30 ms
●Server Backend Latencies 30 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 30 ms
○INP breakdown
○User Timing marks and measures
○Avoid non-composited animations
○Avoid large layout shifts
98

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.

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
March 2026 News div.content > div.card > div.card-body > h5.card-title

These are opportunities to improve keyboard navigation in your application.

○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
●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
●Touch targets have sufficient size and spacing.
●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-hidden="true"]` elements do not contain focusable descendents
○ARIA input fields have accessible names
○ARIA `meter` elements have accessible names
○ARIA `progressbar` elements have accessible names
○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
○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.
○No element has a `[tabindex]` value greater than 0
○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.
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 (Not Found)
Failed to load resource: the server responded with a status of 404 (Not Found)
Manifest fetch from https://www.centos.org/site.webmanifest failed, code 404
Manifest fetch from https://www.centos.org/site.webmanifest failed, code 404
●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
●Page has valid source maps
○Redirects HTTP traffic to HTTPS
○Mitigate clickjacking with XFO or CSP
○Detected JavaScript libraries
82

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.

Content Best Practices

Meta descriptions may be included in search results to concisely summarize page content. Learn more about the meta description.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Descriptive link text helps search engines understand your content. Learn how to make links more accessible.

Why this matters

Performance issues directly impact user engagement and conversion rates.

Format your HTML in a way that enables crawlers to better understand your app’s content.

○Structured data is valid
●Page isn’t blocked from indexing
●Document has a `<title>` element
●Page has successful HTTP status code
●Links are crawlable
●Image elements have `[alt]` attributes
●Document has a valid `hreflang`
○robots.txt is valid
○Document has a valid `rel=canonical`

Send Feedback