Page summary

https://en.wikipedia.org/wiki/Main_Page

Tested 2026-06-23 23:15:37 using Firefox 151.0.3 (script).(runtime settings)

Test visiting multiple pages

First hit the portal page with an empty browser cache and then visit Main_Page

SummaryWaterfall MetricsVideoFilmstrip CoachPageXrayCPU
| Summary | | Download Video | Download HAR | Download Console Logs | 

Summary

LCP2.305 s
Coach88
Loading & responsiveness (median)
TTFB
112 ms
First Paint
378 ms
Fully Loaded
33.057 s
Page weight & requests
Total transfer size
1.2 MB
Requests
42
Visual progress
First Visual Change
433 ms
Speed Index
694 ms
Visual Complete 85%
1.000 s
Visual Complete 99%
2.600 s
Last Visual Change
2.633 s
Screenshot of run 3

Timings Summary

Metricminmedianmeanmax
Visual Metrics
FirstVisualChange400 ms433 ms420 ms433 ms
LastVisualChange2.366 s2.633 s2.693 s3.200 s
SpeedIndex624 ms694 ms698 ms792 ms
LargestImage2.033 s2.600 s2.620 s3.200 s
Heading1.233 s1.500 s1.420 s1.633 s
LargestContentfulPaint1.400 s2.333 s2.173 s2.933 s
LastMeaningfulPaint2.033 s2.600 s2.620 s3.200 s
VisualReadiness1.933 s2.233 s2.273 s2.767 s
VisualComplete85966 ms1.000 s1.026 s1.133 s
VisualComplete951.900 s2.333 s2.373 s2.933 s
VisualComplete992.033 s2.600 s2.620 s3.200 s
Google Web Vitals
Time To First Byte (TTFB)111 ms112 ms112 ms113 ms
Largest Contentful Paint (LCP)1.390 s2.305 s2.153 s2.916 s
More metrics
firstPaint374 ms378 ms380 ms395 ms
loadEventEnd1.387 s2.589 s2.355 s3.167 s
User Timing
mwStartup364 ms371 ms373 ms389 ms
mwCentralNoticeBanner1.170 s1.426 s1.374 s1.594 s
Waterfall | Download HAR | 

Waterfall

Run 3 SpeedIndex median

First paintFCPLCPDOMContentLoadedDOM interactiveLoadRender-blockingRedirectError

Video

Run 3 · median
Download video

Filmstrip

25 frames

Use --filmstrip.showAll to show all filmstrips.

0 s
0.4 sDOM Content Loaded Time 369 msmwStartup 372 msFirst Contentful Paint 379 msFirst Visual Change 400 ms
0.5 s
0.6 s
0.7 s
0.8 s
0.9 s
1 sVisual Complete 85% 966 ms
1.1 s
1.2 s
1.3 s
1.4 s
1.5 smwCentralNoticeBanner 1.426 sHeading 1.500 s
1.6 s
1.7 s
1.8 s
1.9 s
2 s
2.1 s
2.2 s
2.3 s
2.4 sLCP <DIV> 2.357 sVisual Complete 95% 2.400 s
2.5 s
2.6 sPage Load Time 2.589 sVisual Complete 99% 2.600 sLargest Image 2.600 s
2.7 sLast Visual Change 2.633 s
Performance advice | Best practice advice | Privacy advice | Page info | Technologies | 

Coach

The coach helps you find performance problems on your web page using web performance best practice rules. And gives you advice on privacy and best practices. Tested using Coach-core version 9.2.1.

Performance advice

88
9 warnings2 info
warn(0)Serve images in modern formats (AVIF, WebP)modernImageFormats

The page ships 19 images (out of 19) in JPEG/PNG/GIF without a modern alternative. Wrap them in a <picture> with a <source type="image/avif"> or "image/webp" before the legacy <img>, or serve modern formats from your image pipeline directly. AVIF and WebP usually deliver 25–50% smaller files at the same quality.

AVIF and WebP routinely deliver 25–50% smaller files than JPEG and PNG at the same perceived quality, and every browser version still under support understands at least one of them. Ship modern formats either through a <picture> element with <source type="image/avif"> / "image/webp" entries in front of the legacy <img>, or directly from a content-negotiating image pipeline that returns AVIF / WebP when the client accepts it. https://web.dev/articles/serve-images-webp

Offenders
warn(0)Avoid extra requests by setting cache headerscacheHeaders

The page has 24 requests that are missing a cache time. Configure a cache time so the browser doesn't need to download them every time. It will save 801.1 kB the next access.

The easiest way to make your page fast is to avoid doing requests to the server. Setting a cache header on your server response will tell the browser that it doesn't need to download the asset again during the configured cache time! Always try to set a cache time if the content doesn't change for every request.

Offenders
warn(14)Lazy-load below-the-fold imageslazyLoadingImages

The page has 12 below-the-fold images without loading="lazy". Add loading="lazy" so the browser defers downloading and decoding them until the user scrolls them into view.

Adding loading="lazy" to an <img> tells the browser not to download or decode it until it is close to the viewport. For images that the user may never see (deep in the page, behind a tab, in a footer carousel), this saves bandwidth and main-thread time during initial render. The LCP image and any image in the initial viewport should NOT be lazy-loaded — that delays the first paint. https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#loading

Offenders
warn(50)Total JavaScript size shouldn't be too bigjavascriptSize
warn(60)Don't scale images in the browseravoidScalingImages

The page has 4 images that are scaled more than 100 pixels. It would be better if those images are sent so the browser don't need to scale them.

It's easy to scale images in the browser and make sure they look good in different devices, however that is bad for performance! Scaling images in the browser takes extra CPU time and will hurt performance on mobile. And the user will download extra kilobytes (sometimes megabytes) of data that could be avoided. Don't do that, make sure you create multiple version of the same image server-side and serve the appropriate one.

Offenders
infoAdd decoding="async" to non-critical imagesdecodingAsync

The page has 7 images (out of 24) without a decoding hint. Add decoding="async" to non-critical images so the browser can decode them off the main thread.

Setting decoding="async" on an <img> tells the browser it can decode the image off the main thread, which keeps the page responsive to user interactions while images are being processed. The default ("auto") leaves the choice to the browser. https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#decoding

Offenders
infoLong cache headers is goodcacheHeadersLong
warn(90)Avoid doing redirectsassetsRedirects

The page has 1 redirect. 1 of the redirects are from the base domain, please fix them!

A redirect is one extra step for the user to download the asset. Avoid that if you want to be fast. Redirects are even more of a showstopper on mobile.

Offenders
warn(90)Don't use private headers on static contentprivateAssets

The page has 2 requests with private headers. The main page has a private header. It could be right in some cases where the user can be logged in and served specific content. But if your asset is static it should never be private. Make sure that the assets really should be private and only used by one user. Otherwise, make it cacheable for everyone.

If you set private headers on content, that means that the content are specific for that user. Static content should be able to be cached and used by everyone. Avoid setting the cache header to private.

Offenders
warn(95)Avoid slowing down the critical rendering pathavoidRenderBlocking

The style https://en.wikipedia.org/w/load.php?lang=en&modules=ext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediamessages.styles%7Cmediawiki.skins.legacy%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022 is larger than the magic number TCP window size 14.5 kB. Make the file smaller and the page will render faster. The page has 1 render blocking CSS request and 0 blocking JavaScript request inside of head.

The critical rendering path is what the browser needs to do to start rendering the page. Every file requested inside of the head element will postpone the rendering of the page, because the browser need to do the request. Avoid loading JavaScript synchronously inside of the head (you should not need JavaScript to render the page), request files from the same domain as the main document (to avoid DNS lookups) and inline CSS for really fast rendering and a short rendering path.

Offenders
warn(95)Inline CSS for faster first renderinlineCss

The page has both inline CSS and CSS requests even though it uses a HTTP/2-ish connection. If you have many users on slow connections, it can be better to only inline the CSS. Run your own tests and check the waterfall graph to see what happens.

In the early days of the Internet, inlining CSS was one of the ugliest things you can do. That has changed if you want your page to start rendering fast for your user. Always inline the critical CSS when you use HTTP/1 and HTTP/2 (avoid doing CSS requests that block rendering) and lazy load and cache the rest of the CSS. It is a little more complicated when using HTTP/2. Does your server support HTTP push? Then maybe that can help. Do you have a lot of users on a slow connection and are serving large chunks of HTML? Then it could be better to use the inline technique, becasue some servers always prioritize HTML content over CSS so the user needs to download the HTML first, before the CSS is downloaded.

Best practice advice

66
1 error1 warning5 info
error(0)Cumulative Layout ShiftcumulativeLayoutShift

Layout Shift is not supported in this browser

Cumulative Layout Shift measures the sum total of all individual layout shift scores for unexpected layout shift that occur. The metric is measuring visual stability by quantify how often users experience unexpected layout shifts. It is one of Google Web Vitals.

infoMeta descriptionmetaDescription

The page is missing a meta description.

Use a page description to make the page more relevant to search engines.

infoAvoid unnecessary headersunnecessaryHeaders

There are 15 responses that sets both a max-age and expires header. There are 42 responses that sets a server header.

Do not send headers that you don't need. We look for p3p, cache-control and max-age, pragma, server and x-frame-options headers. Have a look at Andrew Betts - Headers for Hackers talk as a guide https://www.youtube.com/watch?v=k92ZbrY815c or read https://www.fastly.com/blog/headers-we-dont-want.

Offenders
warn(50)Set a sensible viewport meta tagviewport

The viewport meta tag does not contain width=device-width, the browser may use a desktop-width fallback.

The viewport meta tag tells the browser how to lay out the page on small screens. Without it (or without width=device-width) the page is rendered at a desktop fallback width and scaled down, which makes text unreadable on mobile. Disabling zoom (user-scalable=no, maximum-scale<=1) is also an accessibility regression. https://developer.mozilla.org/en-US/docs/Web/HTML/Viewport_meta_tag

infoGive every image a textual alternativeimageAltText

The page has 1 image without an alt attribute. Add alt="..." with a description, or alt="" if the image is purely decorative.

Every <img> needs an alt attribute. Use alt="meaningful description" for content images so assistive technologies can announce them, or alt="" (or role="presentation" / aria-hidden="true") for purely decorative images so they are skipped. A missing alt attribute leaves screen reader users with no information at all. https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#alt

Offenders
infoDo not send too long headerslongHeaders

https://en.wikipedia.org/wiki/Main_Page has a header content-security-policy that is 4501 characters long. https://en.wikipedia...ia.org/w/load.php has a header sourcemap that is 1037 characters long.

Do not send response headers that are too long.

Offenders
infoAvoid use too many response headersmanyHeaders

https://en.wikipedia...leadership_crisis has 32 headers.

Avoid send too many response headers.

Offenders

Privacy advice

80
4 warnings2 info
infoSet a Cross-Origin-Embedder-Policy header so cross-origin subresources opt in to being embedded.crossOriginEmbedderPolicyHeader

Set a Cross-Origin-Embedder-Policy header (typically require-corp or credentialless) on the document response to control cross-origin embedding.

Cross-Origin-Embedder-Policy (COEP) makes the page refuse to load cross-origin subresources unless they explicitly opt in via CORP or CORS. Together with Cross-Origin-Opener-Policy it puts the page in a cross-origin isolated context, which mitigates cross-window side-channel attacks (Spectre) and unlocks high-resolution timers and SharedArrayBuffer. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cross-Origin-Embedder-Policy

Offenders
warn(0)Set a Cross-Origin-Opener-Policy header to isolate the page from cross-origin windows.crossOriginOpenerPolicyHeader

Set a Cross-Origin-Opener-Policy header (typically same-origin) on the document response to isolate the page from cross-origin windows.

Cross-Origin-Opener-Policy (COOP) lets a page sever its window-group ties to cross-origin documents that opened it or that it opens. Together with Cross-Origin-Embedder-Policy it puts the page in a cross-origin isolated context, which mitigates cross-window side-channel attacks (Spectre) and unlocks high-resolution timers and SharedArrayBuffer. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cross-Origin-Opener-Policy

Offenders
infoSet a Cross-Origin-Resource-Policy header to limit who may embed the page.crossOriginResourcePolicyHeader

Set a Cross-Origin-Resource-Policy header (same-origin, same-site or cross-origin) on the document response to limit who may embed it.

Cross-Origin-Resource-Policy (CORP) is a per-response opt-in that tells the browser which origins are allowed to embed the resource. It blocks cross-origin or cross-site no-cors embedding (img, script, iframe, etc.) and is one of the building blocks of cross-origin isolation. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cross-Origin-Resource-Policy

Offenders
warn(0)Set a Permissions-Policy header to control which browser features the page can use.permissionsPolicyHeader

Set a Permissions-Policy header to control which browser features the page can use.

The Permissions-Policy response header (the successor to Feature-Policy) lets a site explicitly opt in or out of powerful browser features such as camera, microphone, geolocation, payment and clipboard. Setting a strict policy reduces the attack surface and limits what embedded third parties can do. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Permissions-Policy

Offenders
warn(0)Set a referrer-policy header to make sure you do not leak user information.referrerPolicyHeader

Set a referrer-policy header to make sure you do not leak user information.

Referrer Policy is a new header that allows a site to control how much information the browser includes with navigations away from a document and should be set by all sites. https://scotthelme.co.uk/a-new-security-header-referrer-policy/.

Offenders
warn(30)Use a strict Content-Security-Policy header to mitigate cross-site scripting (XSS) attacks.contentSecurityPolicyHeader

The policy allows 'unsafe-inline', which lets the browser execute inline scripts and styles directly from the page. Move to nonces or hashes plus 'strict-dynamic' so that inline injection cannot run. The policy allows 'unsafe-eval', which lets the page call eval() and Function(). Almost no application needs this; remove it.

A Content-Security-Policy response header tells the browser which sources of script, style, and other content are allowed. The most effective form is a strict CSP using nonces or hashes together with strict-dynamic; the worst is a missing header, with unsafe-inline and unsafe-eval close behind. https://web.dev/articles/strict-csp

Page info

Page info

TitleWikipedia, the free encyclopedia
GeneratorMediaWiki 1.47.0-wmf.7
Width1920
Height3595
DOM elements2330
Avg DOM depth14
Max DOM depth21
Iframes0
Script tags5
Local storage969.0 KB
Session storage0 b
Network Information APIunknown

Resource hints

3 hints
dns-prefetch
  • https://meta.wikimedia.org/
  • https://en.wikipedia.org/wiki/auth.wikimedia.org
preconnect
  • https://upload.wikimedia.org/

Technologies used to build the page

Data collected using Coach-core version 9.2.1. With updated code from Webappanalyzer 2026-05-04. Use --browsertime.firefox.includeResponseBodies html or --browsertime.chrome.includeResponseBodies html to help Wappalyzer find more information about technologies used.

Detected technologies

4 technologies
  • MediaWikiConfidence100
    Wikis
  • PHPConfidence100
    Programming languages
  • HSTSConfidence100
    Security
  • HTTP/2Confidence100
    Miscellaneous
Visual Metrics | Google Web Vitals | Largest Contentful Paint | Browser metrics | Visual Elements | Server timings | 

Data from run 3

Visual Metrics

Visual progress
Visual progress at 0 s0.0s
Visual progress at 0.6 s0.6s
Visual progress at 1 s1.0s
Visual progress at 1.3 s1.3s
Visual progress at 1.7 s1.7s
Visual progress at 2 s2.0s
Visual progress at 2.4 s2.4s
Visual progress at 2.7 s2.7s
FCP0.38s
LCP2.36s
VC850.97s
0.0s0.5s1.1s1.6s2.2s2.7s

Google Web Vitals

from run 3

Largest Contentful Paint

When the page main content is rendered, collected via the Largest Contentful Paint API. Read more about Largest Contentful Paint.

2.357 sLCP render time

Phase breakdown

  • TTFB112 ms
  • Resource load delay1.340 s
  • Resource load duration901 ms
  • Element render delay4 ms

Element

Element type
<div>
Size (w × h)
72274
URL
https://upload.wikim...y_banner_2023.jpg
Load time
2.354 s

DOM path

body > div:eq(2) > div > div:eq(0) > div#siteNotice > div#centralNotice > div > div#wlm-de > a > div:eq(1)
LCP

The LCP element is highlighted in the screenshot. If nothing is highlighted the element was removed before the screenshot or the LCP API couldn't find it.

The Largest Contentful Paint API matched this image:

LCP element

Browser Metrics

Navigation Timing
Extra timings
User Timing marks
mwStartup372 ms
mwCentralNoticeBanner1.426 s

Server timings

2 entries
NameDurationDescription
cache0 mshit-front
host0 mscp3070

Custom metrics collected through JavaScript

There are no custom configured scripts.

Extra metrics collected using scripting

There are no custom extra metrics from scripting.

Visual Elements3
LargestImage500px-Keir_Starmer_and_Andy_Burnham_%2855204794065%29.jpg
Display time2.600 s
Position (x, y)758, 471
Size (w × h)320 × 192
HTML snippet
<img class="mwe-popups-thumbnail" src="https://upload.wikimedia.org/wikipedia/commons/thumb/0/07/Keir_Starmer_and_Andy_Burnham_%2855204794065%29.jpg/500px-Keir_Starmer_and_Andy_Burnham_%2855204794065%29.jpg">
LargestImage preview
Heading
Display time1.500 s
Position (x, y)676, 247
Size (w × h)288 × 49
HTML snippet
<h1 id="Welcome_to_Wikipedia" class="html-heading mw-html-heading"></h1>
LargestContentfulPaint
Display time2.400 s
Position (x, y)375, 91
Size (w × h)946 × 76
HTML snippet
<div class="wlm-image"></div>
Summary | Largest responses | Per content type | Per domain | Expires & last-modified | 

PageXray

How the page is built.

HTTP versionHTTP/2.0
Total requests42
Total domains4
Transfer size1.2 MB
Content size0 b
Missing compression0
Cookies230 third-party

Response codes

200
4095.2%
202
12.4%
302
12.4%

Requests and sizes per content type

8 types
ContentHeader SizeTransfer SizeContent SizeRequests
html5.9 KB52.8 KB0 b1
css2.2 KB26.8 KB0 b2
javascript11.1 KB278.8 KB0 b8
image40.7 KB772.3 KB0 b21
favicon1.0 KB2.1 KB0 b1
svg7.4 KB64.5 KB0 b6
json1.7 KB2.6 KB0 b1
plain1.0 KB1.0 KB0 b1
Total71.0 KB1.2 MB0 b41

Data per domain

4 domains
DomainTotal download timeTransfer SizeContent SizeRequests
en.wikipedia.org4.118 s420.7 KB0 b19
upload.wikimedia.org45.437 s776.7 KB0 b21
meta.wikimedia.org241 ms2.9 KB0 b1
auth.wikimedia.org899 ms1.6 KB0 b1

Expires & last-modified statistics

typeminmedianmax
Expires0 seconds0 seconds1 year
Last modified3 seconds3 weeks3 years

CPU