Page summary

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

Tested 2026-07-27 21:04:23 using Chrome 150.0.7871.186 (runtime settings)

SummaryWaterfallMetricsRenderingCoachPageXrayCPU

This page is fast to paint, snappy to interact with and visually stable, but loose on best practices and weak on user privacy.

81 / 100
Coach overall
83 / 100
Performance
78 / 100
Best practice
80 / 100
Privacy

How it loaded →

0 → 1.733 s · median run
Frame at 0 ms
start
Frame at 900 ms
900 ms
Frame at 1300 ms
Largest paint1.300 s
Frame at 1900 ms
1.900 s
Frame at 2200 ms
2.200 s
Frame at 2300 ms
Complete2.300 s
1.167 s
First Visual Change
1.188 s
Speed Index
1.167 s
Visual Complete 85%
1.733 s
Last Visual Change
TTFB404 msLCP1.208 sTBT18 msCLS0.00

What to act on · top recommendations

Serve images in modern formats (AVIF, WebP)

0 / 100

The page ships 78 images (out of 78) 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.

Avoid extra requests by setting cache headers

0 / 100

The page has 32 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 394.7 kB the next access.

Total JavaScript size shouldn't be too big

0 / 100

The total JavaScript transfer size is 316.8 kB and the uncompressed size is 1.3 MB. This is totally crazy! There is really room for improvement here.

Google Web Vitals

min · median · mean · max of 5 runs
MetricMinMedianMeanMaxRuns agree?
Time To First Byte (TTFB)403 ms404 ms404 ms405 msstable ±1%
Largest Contentful Paint (LCP)1.168 s1.208 s1.199 s1.228 sstable ±2%
Cumulative Layout Shift (CLS)0.00050.00050.00050.0005identical

Visual Metrics

min · median · mean · max of 5 runs
MetricMinMedianMeanMaxRuns agree?
First visual change1.166 s1.167 s1.193 s1.233 sstable ±3%
Last visual change1.700 s1.733 s1.913 s2.233 sruns disagree ±15%
Speed index1.177 s1.188 s1.207 s1.242 sstable ±3%
Largest image1.200 s1.233 s1.233 s1.266 sstable ±3%
Heading1.166 s1.167 s1.193 s1.233 sstable ±3%
Largest contentful paint1.166 s1.167 s1.193 s1.233 sstable ±3%
Last meaningful paint1.200 s1.233 s1.233 s1.266 sstable ±3%
Visual readiness500 ms533 ms720 ms1.067 sruns disagree ±53%
Visual complete 851.166 s1.167 s1.193 s1.233 sstable ±3%
Visual complete 951.166 s1.167 s1.193 s1.233 sstable ±3%
Visual complete 991.600 s1.633 s1.813 s2.133 sruns disagree ±16%

CPU

min · median · mean · max of 5 runs
MetricMinMedianMeanMaxRuns agree?
Total Blocking Time13 ms18 ms18 ms24 msruns disagree ±31%
Max Potential FID58 ms59 ms61 ms67 msvaries ±8%
CPU long tasks 3334runs disagree ±17%
CPU last long task happens at1.599 s1.622 s1.808 s2.131 sruns disagree ±16%

More metrics

min · median · mean · max of 5 runs
MetricMinMedianMeanMaxRuns agree?
First paint1.168 s1.208 s1.199 s1.228 sstable ±2%
Load event end1.758 s1.912 s1.863 s1.927 sstable ±4%

User Timing

min · median · mean · max of 5 runs
MetricMinMedianMeanMaxRuns agree?
mwStartup839 ms840 ms972 ms1.177 sruns disagree ±20%

Waterfall

Run 5 SpeedIndex median

First paintFCPLCPDOMContentLoadedDOM interactiveLoadRender-blockingRedirectError

Rendering

Run 5 · median
0.000 s
0s1s2s

The red band on the timeline marks when the main thread was busy with long tasks: moments when the page could not paint or respond, however the video looks.

Download video

Filmstrip

8 frames

Use --filmstrip.showAll to show all filmstrips.

Frame at 0 ms
0 ms
0 %
Frame at 900 ms
900 ms
0 %
Frame at 1.200 s
1.200 s
95 %
Frame at 1.300 s
1.300 s
98 %
Frame at 1.900 s
1.900 s
98 %
Frame at 2.000 s
2.000 s
98 %
Frame at 2.200 s
2.200 s
99 %
Frame at 2.300 s
2.300 s
100 %

Click a frame to seek the video to that moment. The dot marks frames where the page changed visually.

Visual instability

13.57 % of pixels ever changed · 0 % changed 5+ times
Heatmap of how often each pixel changed while the page loaded

The whole recording in one image: every pixel is tinted by how often it changed. Amber changed once, deep red changed ten or more times. The scale is fixed, so heatmaps from different runs compare directly.

Flat amber is a page that painted once and stayed put. Red speckle in the shape of the text means the same pixels repainted over and over, usually invisible rendering noise that inflates Last Visual Change and Speed Index. A solid red block is a genuinely restless area, like an ad or a carousel.

Frames

How smoothly Chrome delivered frames to the screen during the test. Dropped counts only frames Chrome flags as affecting smoothness. On mostly-static pages the longest gap includes idle time where there was simply nothing to draw.

Frames shown15
Partial2
Dropped0
Effective FPS13.3
Longest gap404 msat 1.480 s

Why was rendering delayed?

Rendering was not meaningfully delayed. First paint landed at 1.168 s on a 404 ms first byte; the 2 render-blocking requests were done by 826 ms and the remaining ~342 ms is style and layout work (131 ms of it measured style recalculation).

Style recalculation

measured by Chrome during this run

Style the browser had to recalculate before it could paint: many elements or a lot of time spent here points at expensive CSS on the critical rendering path. The recalculation count and the largest single one tell the two problems apart: one massive style change touching most of the page (few recalculations, the largest close to the total) needs different medicine than thousands of tiny ones (many recalculations, each tiny).

One large recalculation dominates. Restyling 10 544 elements cost 131 ms before the page painted (11.2 % of the time to First Contentful Paint), and a single recalculation of 10 116 elements accounts for 124 ms of it. Look for one class or inline-style change on a large container near the top of the DOM that restyles the whole subtree at once. The changes driving it are listed under Style invalidations below.

Before first & largest contentful paint (same paint, 1.168 s)

Recalculations8
Elements10544
Total time130.772 ms
Largest recalculation10116 elements · 123.799 ms

The recalculation work before first paint is 11.2 % of the time to First Contentful Paint.

Render blocking requests

3 requests · 51.5 KB

Blocking requests delay both paints: the browser renders nothing until they arrive, so they push First Contentful Paint and everything after it, including the largest paint (LCP). Requests that block the parser inside the body stall everything after them in the document. Load JavaScript with defer or async, and keep non-critical CSS off the critical path with media attributes. Bars show when each request loaded on a clock that runs to the last paint; the gap after the bars is style and layout work.

RequestWhen it loadedTransferDownload
document
en.wikipedia.org · TTFB 404 ms
819 ms
182.4 KB818 ms
ext.cite.parsoid.styles + 13 more modulesblocking
css · load.php styles batch · en.wikipedia.org
403 ms
26.0 KB403 ms
site.stylesblocking
css · load.php styles batch · en.wikipedia.org
343 ms
3.2 KB343 ms
startuppotentially blocking
javascript · load.php startup · en.wikipedia.org
411 ms
22.3 KB411 ms
0292 ms584 msFCP · LCP 1.168 s

Slowest CSS selectorsProfile run

How long Chrome spent testing each CSS selector against the page while recalculating styles. A selector with many match attempts and zero matches is evaluated against the document over and over for rules that never apply.

Selector matching cost 89 ms. The wasted-work list below (selectors tried thousands of times that never match) is the place to start.

Matching time89 ms
Match attempts1 533 886
Matches70 902

Selectors by matching time

top 25
SelectorTimeAttemptsMatches
[rel~="mw:referencedBy"]::before2.00 ms5 9801 352
body.mw-mmv-lightbox-open > :not(.mw-notification-area-overlay)1.94 ms11 8590
a:where(:not([role="button"])):visited:hover1.77 ms11 5400
a:where(:not([role="button"])):visited1.73 ms11 5404 966
a:where(:not([role="button"])):visited:active1.65 ms11 5400
figure[typeof~="mw:File/Thumb"] > :not(figcaption)1.62 ms44 27016
figure[typeof~="mw:File/Frame"] > :not(figcaption)1.34 ms44 2700
.mw-body blockquote > :first-child1.27 ms22 1350
a:visited1.26 ms11 5404 967
.mw-parser-output a1.26 ms5 7684 848

Wasted selector work: attempts that never match

top 25
SelectorAttemptsTime
figure[typeof~="mw:File/Frame"] > :not(figcaption)44 2701.34 ms
.cdx-message__content > :first-child22 1350.59 ms
.mw-body blockquote > :first-child22 1351.27 ms
.mw-body blockquote > :last-child22 1351.07 ms
.center *22 1350.75 ms
.cdx-message__content > :last-child22 1350.67 ms
.skin-theme-clientpref-night .ns-100 .mw-parser-output :not(.notheme):not(a)22 1351.16 ms
.cdx-message__content > *22 1350.82 ms
.cdx-message__content > :first-child11 9000.32 ms
.cdx-dialog__body > :first-child11 9000.53 ms

Style invalidationsProfile run

Why the browser had to recalculate style and layout: every DOM/style change invalidates some set of nodes, and the same class or attribute churning over and over is the pattern to hunt. Counts, not milliseconds: the time is in the style recalculation numbers above.

Chase what keeps changing after the page is up. 2 225 style recalculations and 1 659 layout invalidations fired after first paint, on a page the user was already looking at. The biggest driver is attribute title (271×). Start with the script under "Scripts causing invalidations" that keeps triggering it.

Style recalculations2 2562 225 after first paint
Layout invalidations18 8081 659 after first paint

Changes that keep invalidating

top 15
  • attribute: title271×
  • attribute: class74×
  • attribute: role37×
  • attribute: hidden27×
  • pseudo: only-child20×
  • pseudo: has14×
  • pseudo: first-child13×
  • attribute: style12×
  • pseudo: last-child
  • class: mw-made-collapsible
  • class: jquery-tablesorter
  • class: mw-collapsed
  • attribute: href
  • pseudo: link
  • pseudo: visited

Invalidation reasons

split at first paint

After first paint

Invalidations on a page the user was already looking at, the actionable half.

ReasonStyle recalculationsLayout
Related style rule1 302
A stylesheet rule changed827
A node was inserted into the page65
A :has() selector was re-evaluated:has() re-checks a whole subtree on any change inside it. Scope it tightly, or toggle a class in JavaScript instead.14
Attribute11
An @keyframes rule changed4
JavaScript changed an inline styleSet a class instead of writing element.style, so the browser can batch the work.2
An element entered layout446
An element left layout944
List value change230
A style change forced layout21
An element's size changed7
Unknown7
An SVG element changed3
Scrollbar changed1

Before first paint: building the page

The page being constructed and styled for the first render. Expected work, shown for scale.

ReasonStyle recalculationsLayout
A stylesheet rule changed1
A node was inserted into the page30
An element entered layout17 128
An element left layout2
A style change forced layout1
An element's size changed10
Unknown4
An SVG element changed2
Scrollbar changed2

Scripts causing invalidations

top 8

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

83
10 warnings3 info
warn(0)Serve images in modern formats (AVIF, WebP)modernImageFormats

The page ships 78 images (out of 78) 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 32 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 394.7 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(0)Total JavaScript size shouldn't be too bigjavascriptSize

The total JavaScript transfer size is 316.8 kB and the uncompressed size is 1.3 MB. This is totally crazy! There is really room for improvement here.

A lot of JavaScript often means you are downloading more than you need. How complex is the page and what can the user do on the page? Do you use multiple JavaScript frameworks?

Offenders
URLTransferContent
https://en.wikipedia.org/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=vector-202222.3 KB67.2 KB
https://en.wikipedia.org/w/load.php...ia.org/w/load.php7.9 KB22.7 KB
https://en.wikipedia.org/w/load.php...ia.org/w/load.php17.8 KB60.5 KB
https://en.wikipedia.org/w/load.php...ia.org/w/load.php230.9 KB934.3 KB
https://en.wikipedia.org/w/load.php...ia.org/w/load.php26.1 KB122.6 KB
https://en.wikipedia.org/w/load.php...ia.org/w/load.php2.9 KB14.9 KB
https://auth.wikimedia.org/metawiki/wiki/Special:CentralAutoLogin/checkLoggedIn...gin/checkLoggedIn1.5 KB254 B
warn(3)Lazy-load below-the-fold imageslazyLoadingImages

The page has 72 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(20)Avoid CPU Long TaskslongTasks

The page has 4 CPU long tasks with the total of 442 ms. The total blocking time is 19 ms and 1 long task before first contentful paint with total time of 273 ms. However the CPU Long Task is depending on the computer/phones actual CPU speed, so you should measure this on the same type of the device that your user is using. Use Geckoprofiler for Firefox or Chromes tracelog to debug your long tasks.

Long CPU tasks locks the thread. To the user this is commonly visible as a "locked up" page where the browser is unable to respond to user input; this is a major source of bad user experience on the web today. However the CPU Long Task is depending on the computer/phones actual CPU speed, so you should measure this on the same type of the device that your user is using. To debug you should use the Chrome timeline log and drag/drop it into devtools or use Firefox Geckoprofiler.

Offenders
  • unknown
  • self
  • self
  • unknown
warn(70)Don't scale images in the browseravoidScalingImages

The page has 3 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
infoLong cache headers is goodcacheHeadersLong

The page has 21 requests that have a shorter cache time than one year (but still a cache time).

Setting a cache header is good. Setting a long cache header (a year) is even better because the asset will stay in the browser cache across visits. For content-hashed URLs (e.g. app.4af2.css) you can safely use Cache-Control: max-age=31536000, immutable. For unversioned URLs that may change, use a revalidating strategy instead.

Offenders
warn(80)Don't use private headers on static contentprivateAssets

The page has 3 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(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
infoMake each CSS response smalloptimalCssSize

https://en.wikipedia.org/w/load.php?lang=en&modules=ext.cite.parsoid.styles%7Cext.cite.styles%7Cext.timeline.styles%7Cext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediamessages.styles%7Cjquery.makeCollapsible.styles%7Cjquery.tablesorter.styles%7Cmediawiki.skinning.content.parsoid%7Cmediawiki.skins.legacy%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022 size is 26.7 kB (26685) and that is bigger than the limit of 25 kB. Try to keep each CSS response under 25 kB.

Render-blocking CSS holds up the first paint until it has fully downloaded, parsed and applied, so smaller CSS files mean a faster start. Split your CSS into a small critical bundle inlined or eagerly loaded, with the rest lazy-loaded.

Offenders
URLTransferContent
https://en.wikipedia.org/w/load.php...ia.org/w/load.php26.1 KB211.3 KB
infoAdd decoding="async" to non-critical imagesdecodingAsync

The page has 6 images (out of 83) 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
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.

warn(99)Avoid slowing down the critical rendering pathavoidRenderBlocking

The page has 2 blocking requests and 0 in body parser blocking (0 JavaScript and 2 CSS). There are 1 potentially render blocking requests. You need to verify if it is render blocking: https://en.wikipedia.org/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=vector-2022

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

Best practice advice

78
1 warning4 info
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 25 responses that sets both a max-age and expires header. There are 63 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
infoGive every image a textual alternativeimageAltText

The page has 6 images 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
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

infoDo not send too long headerslongHeaders

https://en.wikipedia...an_Premier_League 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 1345 characters long.

Do not send response headers that are too long.

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

A snapshot of what the browser actually built for this page: the document, how big and deep the DOM tree is and what it kept in storage. Big, deep trees are slower to style and lay out, so the counts Chrome warns about carry a flag.

Page info

Document

What the page says it is and how large it rendered.

TitleIndian Premier League - WikipediaThe document title, shown in the browser tab and used by search results.
GeneratorMediaWiki 1.47.0-wmf.12The tool or CMS that generated the HTML, from the page generator meta tag.
Layout viewport1904 × 31647 pxThe width the page laid out at, and the full height of the rendered document.

DOM structure

How much markup the browser has to build, style and lay out.

DOM elements11,558Very large, slows layout and styleTotal HTML elements. Fewer means less for the browser to style, lay out and paint.
Avg DOM depth16How deeply elements are nested on average.
Max DOM depth37Very deep treeThe deepest nesting on the page. Deep branches cost more style recalculation.
Iframes0No embedded documents on this page.
Script tags5Number of script elements. More scripts usually means more main-thread work.

Storage and connection

What the page stored on the client, and the network it was tested on.

Local storage1.0 MBData the page saved in localStorage, kept across visits.
Session storage0 bData kept in sessionStorage for this tab session only.
Connection type3GWhat the Network Information API reported for the test connection.

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

3 technologies
  • MediaWikiConfidence100
    Wikis
  • PHPConfidence100
    Programming languages
  • HSTSConfidence100
    Security

Data from run 5

Visual Metrics

Visual milestones

all times from navigation start
Speed Index1.19 show quickly the page looked done
First Visual Change1.17 sfirst paint reaches the screen
Last Visual Change2.23 sscreen stops changing · 1.07 s after first
nothing painted yet
≥95% rendered
First Visual Change · Visual Complete 85% · Visual Complete 95%1.17 s
Visual Complete 99%2.13 s
Last Visual Change2.23 s
Visual Readiness1.07 s· first to last change
00.5 s1.0 s1.5 s2.0 s
Visual progress
Visual progress at 0 s0.0s
Visual progress at 0.9 s0.9s
Visual progress at 1.2 s1.2s
Visual progress at 1.3 s1.3s
Visual progress at 1.9 s1.9s
Visual progress at 2 s2.0s
Visual progress at 2.2 s2.2s
Visual progress at 2.3 s2.3s
FCP1.17s
LCP1.17s
VC851.17s
Long tasks
0.0s0.5s0.9s1.4s1.8s2.3s

Google Web Vitals

from run 5

Largest Contentful Paint

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

1.168 sLCP render time

Phase breakdown

  • TTFB404 ms
  • Resource load delay0 ms
  • Resource load duration0 ms
  • Element render delay764 ms

Element

Element type
<p>
Element id
mwNA
Size (w × h)
143520
Load time
0 ms
Style recalculation before LCP
8 recalculations touching 10544 elements (130.772 ms) — the largest touched 10116 elements (123.799 ms)

DOM path

body > div:eq(2) > div > div:eq(2) > main#content > div#bodyContent > div#mw-content-text > div:eq(1) > section#mwAQ > p#mwNA
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.

Cumulative Layout Shift

How much the page's content shifts as it loads, collected via the Cumulative Layout Shift API.

0.001cumulative layout shift score

One shift is 100% of your 0.001 CLS. div#skin-client-prefs-skin-theme moved at 2.197 s. Reserve space for whatever renders into that spot, a fixed height or an aspect-ratio box, so later content stops pushing the page around.

Elements that shifted

Worst first, showing shifts of 0.01 and up. Each percentage is that shift's exact share of the score.

The shift is spread across many movements below 0.01, none large enough to single out. Check the video or filmstrip to see what moved.

Layout shift

Elements that shifted by more than 0.01 are highlighted in the screenshot. If an element shifted outside the viewport, it won't appear here. Check the video or filmstrip to see the shift.

Browser Metrics

Navigation Timing
Extra timings
User Timing marks
mwStartup1.177 s

Server timings

Timing data the server chose to expose through Server-Timing response headers on the main document — typically backend time, cache status or experiment flags.

Server timings

3 entries
NameDurationDescription
cache0 mshit-front
host0 mscp3070
co_id0 ms1553720842

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
LargestImage250px-Indian_Premier_League_Official_Logo.svg.png
Display time1.233 s
Position (x, y)1146, 312
Size (w × h)250 × 128
HTML snippet
<img alt="Tournament logo" resource="https://en.wikipedia.org/wiki/File:Indian_Premier_League_Official_Logo.svg" src="//upload.wikimedia.org/wikipedia/en/thumb/8/84/Indian_Premier_League_Official_Logo.svg/250px-Indian_Premier_League_Official_Logo.svg.png" decoding="async" data-file-width="442" data-file-height="226" data-file-type="drawing" height="128" width="250" srcset="//upload.wikimedia.org/wikipedia/en/thumb/8/84/Indian_Premier_League_Official_Logo.svg/500px-Indian_Premier_League_Official_Logo.svg.png 2x" class="mw-file-element">
LargestImage preview
Heading
Display time1.166 s
Position (x, y)478, 90
Size (w × h)796 × 40
HTML snippet
<h1 id="firstHeading" class="firstHeading mw-first-heading"></h1>
LargestContentfulPaint
Display time1.166 s
Position (x, y)478, 493
Size (w × h)948 × 234
HTML snippet
<p id="mwNA"></p>

PageXray

How the page is built.

HTTP versionHTTP/2.0
Total requests63
Total domains3
Transfer size981.9 KB
Content size3.1 MB
Missing compression0
Cookies370 third-party

Main document

status 200 · 0 redirects

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

HeaderValue
accept-ch
accept-rangesbytes
age17412
cache-controlprivate, s-maxage=0, max-age=0, must-revalidate, no-transform
content-encodinggzip
content-languageen
content-length180553
content-security-policyscript-src 'unsafe-eval' blob: 'self' meta.wikimedia.org *.wikimedia.org *.wikipedia.org *.wikinews.org *.wiktionary.org *.wikibooks.org *.wikiversity.org *.wikisource.org wikisource.org *.wikiquote.org *.wikidata.org *.wikifunctions.org *.wikivoyage.org *.mediawiki.org mediawiki.org wikimedia.org *.wmflabs.org *.wmcloud.org *.toolforge.org wss://*.toolforge.org *.jsdelivr.net unpkg.com cdnjs.cloudflare.com raw.githubusercontent.com *.github.com code.jquery.com cdn.mathjax.org use.typekit.net fonts.cdnfonts.com use.fontawesome.com i.ytimg.com rsms.me doi.org localhost https://localhost:* http://localhost:* wss://localhost:* ws://localhost:* *.google.com *.gstatic.com *.googleapis.com *.translate.yandex.net yastatic.net ya.ru radically.github.io cdn.sammdot.ca cdn.fontshare.com viaf.org publicai-proxy.alaexis.workers.dev iiif.archive.org api.flickr.com live.staticflickr.com api.anthropic.com api.openai.com api.publicai.co catalogo.pusc.it parsifal.urbe.it opac.sbn.it overpass-api.de api.openrouteservice.org archive.org *.openstreetmap.org *.waymarkedtrails.org *.thunderforest.com registry.ipe.wiki analytics.ipe.wiki qlever.dev app.goacoustic.com wikipedia-archive.ourworldindata.org api.inaturalist.org inaturalist-open-data.s3.amazonaws.com validator.w3.org db.onlinewebfonts.com fontlibrary.org 'unsafe-inline' auth.wikimedia.org; default-src 'self' data: blob: upload.wikimedia.org https://commons.wikimedia.org meta.wikimedia.org *.wikimedia.org *.wikipedia.org *.wikinews.org *.wiktionary.org *.wikibooks.org *.wikiversity.org *.wikisource.org wikisource.org *.wikiquote.org *.wikidata.org *.wikifunctions.org *.wikivoyage.org *.mediawiki.org mediawiki.org wikimedia.org *.wmflabs.org *.wmcloud.org *.toolforge.org wss://*.toolforge.org *.jsdelivr.net unpkg.com cdnjs.cloudflare.com raw.githubusercontent.com *.github.com code.jquery.com cdn.mathjax.org use.typekit.net fonts.cdnfonts.com use.fontawesome.com i.ytimg.com rsms.me doi.org localhost https://localhost:* http://localhost:* wss://localhost:* ws://localhost:* *.google.com *.gstatic.com *.googleapis.com *.translate.yandex.net yastatic.net ya.ru radically.github.io cdn.sammdot.ca cdn.fontshare.com viaf.org publicai-proxy.alaexis.workers.dev iiif.archive.org api.flickr.com live.staticflickr.com api.anthropic.com api.openai.com api.publicai.co catalogo.pusc.it parsifal.urbe.it opac.sbn.it overpass-api.de api.openrouteservice.org archive.org *.openstreetmap.org *.waymarkedtrails.org *.thunderforest.com registry.ipe.wiki analytics.ipe.wiki qlever.dev app.goacoustic.com wikipedia-archive.ourworldindata.org api.inaturalist.org inaturalist-open-data.s3.amazonaws.com validator.w3.org db.onlinewebfonts.com fontlibrary.org en.wikibooks.org en.wikinews.org en.wikiquote.org en.wikisource.org en.wikiversity.org en.wikivoyage.org en.wiktionary.org www.mediawiki.org commons.wikimedia.org foundation.wikimedia.org incubator.wikimedia.org species.wikimedia.org wikimania.wikimedia.org www.wikidata.org www.wikifunctions.org auth.wikimedia.org; style-src 'self' data: blob: upload.wikimedia.org https://commons.wikimedia.org meta.wikimedia.org *.wikimedia.org *.wikipedia.org *.wikinews.org *.wiktionary.org *.wikibooks.org *.wikiversity.org *.wikisource.org wikisource.org *.wikiquote.org *.wikidata.org *.wikifunctions.org *.wikivoyage.org *.mediawiki.org mediawiki.org wikimedia.org *.wmflabs.org *.wmcloud.org *.toolforge.org wss://*.toolforge.org *.jsdelivr.net unpkg.com cdnjs.cloudflare.com raw.githubusercontent.com *.github.com code.jquery.com cdn.mathjax.org use.typekit.net fonts.cdnfonts.com use.fontawesome.com i.ytimg.com rsms.me doi.org localhost https://localhost:* http://localhost:* wss://localhost:* ws://localhost:* *.google.com *.gstatic.com *.googleapis.com *.translate.yandex.net yastatic.net ya.ru radically.github.io cdn.sammdot.ca cdn.fontshare.com viaf.org publicai-proxy.alaexis.workers.dev iiif.archive.org api.flickr.com live.staticflickr.com api.anthropic.com api.openai.com api.publicai.co catalogo.pusc.it parsifal.urbe.it opac.sbn.it overpass-api.de api.openrouteservice.org archive.org *.openstreetmap.org *.waymarkedtrails.org *.thunderforest.com registry.ipe.wiki analytics.ipe.wiki qlever.dev app.goacoustic.com wikipedia-archive.ourworldindata.org api.inaturalist.org inaturalist-open-data.s3.amazonaws.com validator.w3.org db.onlinewebfonts.com fontlibrary.org 'unsafe-inline'; object-src 'none'; report-uri /w/api.php?action=cspreport&format=json; report-to csp-report-to-endpoint
content-typetext/html; charset=UTF-8
dateMon, 27 Jul 2026 16:16:12 GMT
last-modifiedMon, 27 Jul 2026 16:11:49 GMT
nel{ "report_to": "wm_nel", "max_age": 604800, "failure_fraction": 0.05, "success_fraction": 0.0}
report-to{ "group": "wm_nel", "max_age": 604800, "endpoints": [{ "url": "https://intake-logging.wikimedia.org/v1/events?stream=w3c.reportingapi.network_error&schema_uri=/w3c/reportingapi/network_error/1.0.0" }] }
reporting-endpointscsp-report-to-endpoint='/w/api.php?action=cspreport&format=json';
servermw-web.eqiad.main-69bbd59d68-cdwv8
server-timingcache;desc="hit-front", host;desc="cp3070",co_id;desc="1553720842"
strict-transport-securitymax-age=106384710; includeSubDomains; preload
varyAccept-Encoding,X-Subdomain,Cookie,Authorization,User-Agent
x-analytics
x-cachecp3070 miss, cp3070 hit/21
x-cache-statushit-front
x-client-ip138.201.135.103
x-content-type-optionsnosniff
x-request-idd5a0c44b-1ad0-4319-af53-1831f200da6f

Response codes

200
6196.8%
202
11.6%
302
11.6%

Requests and sizes per content type

7 types

Transfer size981.9 KB

  • image38.6%
  • javascript31.5%
  • html18.6%
  • svg8.0%
  • css3.0%
  • favicon0.19%
  • plain0.09%

Content size3.1 MB

  • html40.0%
  • javascript38.3%
  • image10.3%
  • css6.8%
  • svg4.6%
  • favicon0.08%

Requests62

  • image45.2%
  • svg35.5%
  • javascript11.3%
  • css3.2%
  • html1.6%
  • favicon1.6%
  • plain1.6%
ContentHeader SizeTransfer SizeContent SizeRequests
html0 b182.4 KB1.2 MB1
css0 b29.3 KB218.0 KB2
javascript0 b309.4 KB1.2 MB7
image0 b379.3 KB328.4 KB28
favicon0 b1.8 KB2.7 KB1
svg0 b78.8 KB145.8 KB22
plain0 b919 B0 b1
Total0 b981.9 KB3.1 MB62

Data per domain

3 domains
DomainTotal download timeTransfer SizeContent SizeRequests
en.wikipedia.org7.889 s596.4 KB2.8 MB32
upload.wikimedia.org16.367 s384.0 KB330.9 KB30
auth.wikimedia.org186 ms1.5 KB254 B1

Expires & last-modified statistics

typeminmedianmax
Expires0 seconds0 seconds1 year
Last modified4 minutes9 weeks8 years

Requests loaded after onLoad event

2 requests

Includes requests done after load event end.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript0 b0
image0 b0
font0 b0
favicon1.8 KB1
plain919 B1
Total2.7 KB2

Requests loaded after onContentLoad

16 requests

Includes requests done after DOM content loaded.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript30.5 KB3
image0 b0
font0 b0
favicon1.8 KB1
svg11.8 KB10
plain919 B1
Total45.0 KB16

CoverageProfile run

JavaScript and CSS coverage from the extra profile run made by --enableProfileRun, not from the timed iterations. For JS, Chrome tracks which blocks of each script actually ran: a byte is unused when the innermost block of code around it never ran. For CSS, Chrome records every selector that no element on the page matched during the iteration. Enable with --chrome.coverage on every run, or --enableProfileRun to keep the main run's timing metrics untouched. Unused bytes still cost network, parse and compile time for no benefit. Expand the section below for the full picture.

How is "unused" calculated?

sitespeed.io drives Chrome's V8 profiler and CSS rule tracker via the DevTools Protocol, the same machinery the DevTools Coverage panel uses. The two columns are populated by two different mechanisms.

JavaScript

Browsertime calls Profiler.startPreciseCoverage with detailed (block-level) mode at the start of the iteration and Profiler.takePreciseCoverage at the end. V8 returns nested ranges per function: an outer range covering the function body and inner ranges for sub-blocks (if/else, switch arms, ternaries). Each range has an execution count. A byte is "used" if the innermost range that covers it has count > 0, "unused" if it has count = 0, so we catch both functions that never ran AND dead branches inside functions that did.

CSS

Browsertime calls CSS.startRuleUsageTracking at the start of the iteration and CSS.stopRuleUsageTracking at the end. Chrome returns a flat list of rule-text ranges with a used flag: a rule is "used" if at least one element on the page matched it during the iteration. Both inline <style> blocks and external stylesheets are included.

What "this iteration" means

Coverage reflects only what executed during this run. Code behind a button click stays unused unless the iteration clicked the button. The collection window opens before navigation and closes when measure.stop() is reached, so the only way to count interactions is to drive them between measure.start() and measure.stop() inside a navigation script (pass a .js file as the input instead of a plain URL). Clicks, form fills and waits placed there all count toward "used". --preScript runs before the URL is loaded so it can't interact with the page being measured, and --postScript runs after coverage has already been collected, so neither helps here. Detailed coverage also tells V8 to skip some optimisations, which drifts timing metrics like LCP and TBT; that's why --enableProfileRun is the safer option for production measurement (it collects coverage in a separate iteration that doesn't count towards the medians).

JS total1.2 MB
JS unused529.2 KB
JS unused %43.2%
CSS total455.8 KB
CSS unused375.5 KB
CSS unused %82.4%

Where the bytes go

25 files · tile size is total bytes, tint is unused share

1.6 MB of script and style shipped, and 904.8 KB of it never ran on this page. The biggest win is load.php[scripts:ext.centralNotice.bannerHistoryLogger]: 930.6 KB delivered, 426.3 KB unused, and inside it jquery alone ships 82.1 KB of dead code.

load.php[scripts:ext.centralNotice.bannerHistoryLogger]930.6 KB · 46% unused
inline220.6 KB · 93% unused
load.php[styles:ext.cite.parsoid.styles]211.3 KB · 75% unused
load.php[scripts:ext.cite.referencePreviews]122.6 KB · 30% unused
load.php[startup]67.2 KB · 9% unused
load.php[scripts:ext.visualEditor.core.utils.parsing]60.5 KB · 74% unused
load.php[scripts:ext.gadget.ReferenceTooltips]22.7 KB · 68% unused
load.php[scripts:mw.config.values.wbCurrentSiteDetails]14.9 KB · 0% unused
17 more files31.5 KB · 44% unused
Unused shareunder 40%40 to 70%over 70%Click a bundle marked ⤢ to see its modules.

Where the unused bytes live

first-party regex (.*wikipedia.*||.*wikimedia.*)
JS unused
First 529.2 KBThird 0 b
CSS unused
First 375.5 KBThird 0 b

JavaScript files

showing 8 of 8 URLs (from 10 scripts), sorted by unused bytes
URLTotalUsedUnusedUnused %
load.php[scripts:ext.centralNotice.bannerHistoryLogger]930.6 KB504.4 KB426.3 KB
45.8%
73 modules in this bundle, by unused bytes
ModuleVersionTotalUsedUnusedUnused %
jqueryxt2am137.4 KB55.3 KB82.1 KB
59.8%
ext.wikimediaEventsqzzfn79.0 KB23.5 KB55.6 KB
70.3%
skins.vector.jssv4bp60.6 KB30.6 KB29.9 KB
49.4%
mediawiki.api2utky27.0 KB5.1 KB22.0 KB
81.2%
ext.uls.interfacei6zf447.2 KB25.9 KB21.3 KB
45.2%
ext.centralNotice.display1jbsp30.5 KB9.2 KB21.3 KB
69.8%
jquery.tablesorter1g8zn19.8 KB6.9 KB12.9 KB
65.2%
mediawiki.jqueryMsg1i0ih29.8 KB18.2 KB11.6 KB
38.8%
ext.testKitchen168ak31.0 KB19.5 KB11.5 KB
37.2%
oojs1u2cw15.0 KB3.5 KB11.4 KB
76.4%
mediawiki.util9btvw16.3 KB6.6 KB9.7 KB
59.4%
ext.navigationTiming1u0am10.8 KB1.4 KB9.3 KB
86.6%
mediawiki.page.ready1pkom16.4 KB7.5 KB8.9 KB
54.4%
mmv.bootstraph6pct25.6 KB18.7 KB7.0 KB
27.2%
mediawiki.language10erv8.7 KB1.7 KB7.0 KB
80.6%
ext.quicksurveys.lib1lxkn14.3 KB7.6 KB6.7 KB
47.1%
mediawiki.page.watch.ajax55z4w8.8 KB2.5 KB6.3 KB
71.7%
ext.eventLogging.metricsPlatform1jqfq16.6 KB10.8 KB5.8 KB
35.2%
ext.centralNotice.kvStorec4zi36.8 KB1.1 KB5.7 KB
83.6%
jquery.textSelection1x0f05.8 KB287 B5.6 KB
95.2%
mediawiki.Titlef7e8e10.2 KB6.1 KB4.1 KB
40.1%
skins.vector.clientPreferences1aamm13.5 KB9.5 KB4.1 KB
30.1%
ext.eventLoggingsatg329.5 KB25.5 KB4.0 KB
13.5%
ext.wikimediaEvents.testKitchen16e4i4.6 KB785 B3.9 KB
83.4%
ext.centralauth.ForeignApiveaum4.6 KB776 B3.8 KB
83.5%
jquery.uls.data1150b42.8 KB39.1 KB3.7 KB
8.7%
mediawiki.base10e5328.0 KB24.4 KB3.6 KB
13.0%
mediawiki.libs.pluralruleparser11fhr3.6 KB197 B3.4 KB
94.7%
ext.centralNotice.bannerHistoryLogger9lh054.0 KB807 B3.2 KB
80.1%
ext.cite.ux-enhancements12mrk4.9 KB1.7 KB3.1 KB
64.6%
jquery.makeCollapsible1ckrd9.2 KB6.1 KB3.1 KB
33.3%
mw.cx.SiteMapper3goe44.3 KB1.3 KB3.0 KB
69.6%
ext.urlShortener.toolbaryecdv3.8 KB1.1 KB2.7 KB
70.9%
mediawiki.userdaofm4.2 KB1.7 KB2.5 KB
58.8%
ext.checkUser.clientHints13jk23.0 KB635 B2.4 KB
79.3%
ext.centralNotice.impressionDietvfmsr2.7 KB446 B2.3 KB
83.9%
ext.uls.common1h4lr5.4 KB3.1 KB2.3 KB
42.0%
ext.cx.uls.quick.actions3pl8o3.1 KB1.2 KB1.9 KB
61.7%
mediawiki.String1xuwk2.4 KB543 B1.9 KB
78.0%
ext.centralNotice.largeBannerLimit12rqy2.2 KB479 B1.8 KB
78.9%
mediawiki.routernss952.4 KB761 B1.7 KB
69.3%
jquery.client5k8ja3.3 KB1.9 KB1.4 KB
42.2%
ext.uls.webfonts86xg22.0 KB663 B1.4 KB
67.8%
mediawiki.ForeignApi.core1mk9b2.2 KB863 B1.3 KB
61.1%
ext.centralNotice.startUpei35p2.7 KB1.5 KB1.1 KB
42.4%
mediawiki.visibleTimeout40nxy1.5 KB434 B1.1 KB
71.5%
mediawiki.storage3elpb2.9 KB2.2 KB727 B
24.2%
ext.centralNotice.geoIPwookz1.5 KB850 B698 B
45.1%
mediawiki.tocui5eu1.2 KB531 B666 B
55.6%
mediawiki.cookienechy3.2 KB2.6 KB620 B
18.7%
ext.uls.rewrite.entrypoints15r141.8 KB1.2 KB607 B
32.7%
jquery.spinneriute0827 B234 B593 B
71.7%
mediawiki.page.media1oc5n949 B501 B448 B
47.2%
ext.uls.preferences1i0ug1.1 KB645 B445 B
40.8%
ext.centralauth.centralautologin8kstq1.3 KB962 B325 B
25.3%
wikibase.client.vector-2022tunx01.9 KB1.6 KB256 B
13.3%
ext.centralNotice.legacySupport18wyo453 B254 B199 B
43.9%
mediawiki.cldr100c7350 B153 B197 B
56.3%
ext.cx.eventlogging.campaigns19v0k347 B187 B160 B
46.1%
ext.echo.centralauthw08f7340 B220 B120 B
35.3%
wikibase.databox.fromWikidataqmair709 B640 B69 B
9.7%
ext.popups13p6r735 B672 B63 B
8.6%
mediawiki.experiments15xww780 B756 B24 B
3.1%
ext.centralNotice.choiceDatauvz9c12.7 KB12.7 KB4 B
0.0%
ext.cx.model115fa224 B224 B0 b
0.0%
ext.quicksurveys.initw6q71345 B345 B0 b
0.0%
siteslpki2.1 KB2.1 KB0 b
0.0%
jquery.spinner.stylesvyjl02.2 KB2.2 KB0 b
0.0%
mediawiki.ForeignApir63m672 B72 B0 b
0.0%
mediawiki.editfont.stylesl9cd21003 B1003 B0 b
0.0%
mediawiki.language.months1p6in1.4 KB1.4 KB0 b
0.0%
mmv.codex1inu869.8 KB69.8 KB0 b
0.0%
skins.vector.icons.jspoepj13.2 KB13.2 KB0 b
0.0%
load.php[scripts:ext.visualEditor.core.utils.parsing]60.5 KB15.7 KB44.8 KB
74.1%
8 modules in this bundle, by unused bytes
ModuleVersionTotalUsedUnusedUnused %
ext.visualEditor.desktopArticleTarget.initrm66a31.3 KB10.2 KB21.1 KB
67.4%
ext.visualEditor.targetLoader5li6x21.8 KB2.3 KB19.4 KB
89.4%
ext.visualEditor.core.utils.parsingpxlsz3.3 KB800 B2.5 KB
76.5%
ext.visualEditor.tempWikitextEditorWidgetbm2az1.5 KB770 B790 B
50.6%
ext.visualEditor.progressBarWidgetbno9f1.3 KB726 B627 B
46.3%
ext.visualEditor.vefb3kh303 B124 B179 B
59.1%
ext.visualEditor.supportCheck1ogmv721 B611 B110 B
15.3%
ext.visualEditor.track10mz7295 B192 B103 B
34.9%
load.php[scripts:ext.cite.referencePreviews]122.6 KB86.4 KB36.2 KB
29.5%
3 modules in this bundle, by unused bytes
ModuleVersionTotalUsedUnusedUnused %
ext.popups.main4i3g792.7 KB65.7 KB27.0 KB
29.1%
ext.cite.referencePreviewswcpta26.6 KB19.8 KB6.7 KB
25.4%
ext.math.popup6zfo93.4 KB931 B2.5 KB
73.3%
load.php[scripts:ext.gadget.ReferenceTooltips]22.7 KB7.2 KB15.5 KB
68.3%
2 modules in this bundle, by unused bytes
ModuleVersionTotalUsedUnusedUnused %
ext.gadget.ReferenceTooltipsrxqhg21.4 KB7.0 KB14.4 KB
67.2%
ext.gadget.switcherneci01.3 KB190 B1.1 KB
85.8%
load.php[startup]67.2 KB61.0 KB6.1 KB
9.1%
(inline) 3 scripts7.3 KB7.2 KB188 B
2.5%
https://en.wikipedia.org/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=script&usesul3=1254 B155 B99 B
39.0%
load.php[scripts:mw.config.values.wbCurrentSiteDetails]14.9 KB14.9 KB0 b
0.0%
3 modules in this bundle, by unused bytes
ModuleVersionTotalUsedUnusedUnused %
mw.config.values.wbCurrentSiteDetailsln29d335 B335 B0 b
0.0%
mw.config.values.wbRepo18lj4211 B211 B0 b
0.0%
oojs-ui.styles.icons-editing-core1mxvb14.4 KB14.4 KB0 b
0.0%

CSS files

showing 17 of 17 URLs (from 20 stylesheets), sorted by unused bytes
URLTotalUsedUnusedUnused %
(inline stylesheet) 4 stylesheets220.6 KB16.3 KB204.3 KB
92.6%
load.php[styles:ext.cite.parsoid.styles]211.3 KB53.5 KB157.8 KB
74.7%
load.php[styles:site.styles]6.7 KB2.1 KB4.6 KB
68.7%
TemplateStyles:r12460913303.1 KB408 B2.7 KB
87.2%
TemplateStyles:r13586202341.3 KB96 B1.2 KB
92.7%
TemplateStyles:r12918844101.6 KB586 B1.1 KB
65.0%
TemplateStyles:r13334331062.1 KB1015 B1.1 KB
51.7%
TemplateStyles:r13272699001.1 KB85 B1.0 KB
92.6%
TemplateStyles:r12394002311.1 KB419 B690 B
62.2%
TemplateStyles:r13331330642.3 KB1.8 KB480 B
20.5%
TemplateStyles:r1314755338851 B654 B197 B
23.1%
TemplateStyles:r1353705441348 B227 B121 B
34.8%
TemplateStyles:r13642795172.1 KB2.0 KB120 B
5.6%
TemplateStyles:r981673959304 B196 B108 B
35.5%
TemplateStyles:r1266661725783 B721 B62 B
7.9%
TemplateStyles:r1152813436194 B194 B0 b
0.0%
TemplateStyles:r103884131971 B71 B0 b
0.0%

What to do about unused bytes

one iteration is a sample, not a verdict

A high unused-% on one run means this iteration loaded code that didn't get exercised, typical on first-load journeys before any user interaction. Drive the real flow by passing a navigation script as the input instead of a plain URL, with clicks and form fills placed between measure.start() and measure.stop(); anything in that window counts toward "used". The advice below is for code that's still unused after a representative run.

JavaScript

  • Route-split and lazy-load below-the-fold features with dynamic import(). Bundlers turn the import boundary into a separate chunk.
  • Audit big bundles for dead exports, legacy polyfills, and feature flags that no longer ship; most modern bundlers tree-shake but only when imports are precise.
  • Question third-party scripts. Tag managers, analytics SDKs and A/B test loaders often ship far more than the page uses and dominate the third-party column above.
  • Move non-critical scripts to defer or async so the parser doesn't block on code the page doesn't need yet.

CSS

  • Strip selectors no shipped HTML matches: PurgeCSS, build-time scoping in your component framework, or your CSS-in-JS extractor.
  • Drop legacy browser fallbacks if your target floor has moved (vendor prefixes, IE hacks, old flexbox syntax).
  • Split route- or component-specific CSS so the home page doesn't carry the checkout's styles.
  • Inline the critical-path CSS (above-the-fold) and lazy-load the rest with media= tricks or rel="preload" swaps.

CPU

Long tasks

Tasks ≥ 50 ms blocking the main thread, collected via the Long Task API.

TBT24 ms
Max potential input delay67 ms
Total long tasks3
Total time389 ms
Last task at2.131 s
Before first paint265 ms1 task
Before FCP265 ms1 task
Before LCP265 ms1 task
After load124 ms2 tasks

Long Animation Frames

A long animation frame (LOAF) is a frame that took ≥ 50 ms from input to the next paint. The part beyond the threshold is blocking time, the number that hurts Interaction to Next Paint and Total Blocking Time. Break long tasks up (scheduler.yield(), smaller chunks) or move the work off the main thread. Read more about the Long Animation Frames API.

Long animation frames6every frame ≥ 50 ms
Blocking time272.6 msacross all long frames — what hurts INP and TBT
Forced style & layout12.3 msscripts reading layout mid-frame
Blocking before LCP196.7 msdelaying the largest paint — fix these first
Blocking after load75.9 msafter the load event — didn't delay page load

What to fix first

ScriptFramesTime runningBlocking (share by run time)Forced style & layoutTriggered by
load.php[startup]383.8 ms30.8 ms12.3 mstimer or animation callback
load.php[scripts:ext.centralNotice.bannerHistoryLogger]294.8 ms29.3 mstimer or animation callback

A frame's blocking time is split between its scripts by their share of the frame's work, capped at each script's own run time — blocking from work no script owns (HTML parsing, browser internals) stays unattributed. The per-script blocking view below uses the same attribution.

Long animation frame #1 · 676.4 msat 416.2 ms · before LCP
blocking 196.7 ms
  • Scripts & other work676.3 ms
  • Animation callbacks0.1 ms
  • Style & layout0 ms
  • Render0 ms

The browser did not report which script was responsible for this frame — typically its own style/layout work, or a cross-origin script it will not name.

Long animation frame #2 · 108.7 msat 1.870 s · after load
blocking 43.6 ms
  • Scripts & other work55.1 ms
  • Animation callbacks44.9 ms
  • Style & layout8.7 ms
  • Render0 ms
2 scripts ran during this frame · forced style & layout 12.3 ms
Ran for
39.9 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 382554 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Ran for
26.3 ms
Forced style and layout
12.3 ms
Started by
FrameRequestCallback
How it started
timer or animation callback
Source function
flushCssBuffer
Position in source
character 3240 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Long animation frame #3 · 84.1 msat 2.113 s · after load
blocking 19.2 ms
  • Scripts & other work18.3 ms
  • Animation callbacks6.1 ms
  • Style & layout59.7 ms
  • Render0 ms
1 script ran during this frame
Ran for
6.1 ms
Started by
FrameRequestCallback
How it started
timer or animation callback
Source function
flushCssBuffer
Position in source
character 3240 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Long animation frame #4 · 57.6 msat 1.806 s · after load
blocking 7.4 ms
  • Scripts & other work38 ms
  • Animation callbacks13.7 ms
  • Style & layout5.9 ms
  • Render0 ms
2 scripts ran during this frame
Ran for
37.7 ms
Started by
IdleRequestCallback
How it started
timer or animation callback
Source function
doPropagation
Position in source
character 4314 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Ran for
13.7 ms
Started by
FrameRequestCallback
How it started
timer or animation callback
Source function
flushCssBuffer
Position in source
character 3240 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Long animation frame #5 · 111.5 msat 1.983 s · after load
blocking 5.7 ms
  • Scripts & other work103.6 ms
  • Animation callbacks7.8 ms
  • Style & layout0.1 ms
  • Render0 ms
2 scripts ran during this frame
Ran for
47.9 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 382554 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Ran for
7 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 382554 into the file (locate it via DevTools → Performance → the Long Animation Frames track)

1 more long frame carried no blocking time (nothing ran past the 50 ms threshold) — long, but harmless to INP and TBT.

Blocking time per script (browser-reported)

How much each script blocked the main thread, derived from the Long Animation Frame API. Each frame's blocking time is split between its scripts by their share of the frame's work, capped at each script's own run time — blocking from work no script owns (HTML parsing, browser internals) is not attributed (older data credits the script that started the frame). The closest answer to "which script should I fix to improve TBT" the platform exposes.

Top scripts blocking the main thread

2 of 2 scripts
load.php[startup]
31 ms · 4 frames · worst 17 ms

Blocking time per script (trace)

Total Blocking Time attributed per script from the Chrome trace: every main-thread task longer than 50 ms blocks input for the remainder, and each blocking task is credited to the script whose own code ran the longest during that task.

TBT242.8 ms
Blocking tasks3
TBT before LCP216.7 ms1 task

What kind of work blocked

mostly style & layout · 243 ms total
Style & layout205.6 ms84.7%
Paint & composite21.2 ms8.7%
Other browser work11.7 ms4.8%
Running JavaScript3.7 ms1.5%
Parsing HTML & CSS0.6 ms0.2%
Style & layout (85%): usually a large DOM, expensive CSS selectors or JavaScript forcing synchronous layout. See Forced reflows · Forced layout per script · Slowest CSS selectors (Rendering tab) · Style invalidations (Rendering tab)

Top scripts blocking the main thread

2 of 2 scripts
Browser's own work (no script responsible)
217 ms · 1 task
load.php[startup]
26 ms · 2 tasks

Where the time went

All main-thread work during the full page load, not just the share that blocked input. Calculated from the Chrome trace.

Categories

1.024 s total
Style & layout395 ms38.6%
Running JavaScript266 ms26.0%
Other browser work (scheduling)163 ms15.9%
Parsing HTML & CSS103 ms10.1%
Paint & composite83 ms8.1%
Garbage collection10 ms1.0%
Parsing & compiling JavaScript4 ms0.4%
What do these categories mean?
Parsing HTML & CSSparseHTML
Reading the HTML and CSS and building the page structure. Grows with document size — a big server-rendered page costs more here.
Style & layoutstyleLayout
Working out which CSS rules apply and where every element goes on the page. Grows with DOM size and selector complexity.
Parsing & compiling JavaScriptscriptParseCompile
Parsing and compiling JavaScript before it can run — the cost of shipping bytes of JS, even unused ones.
Running JavaScriptscriptEvaluation
Running JavaScript: event handlers, timers, promise callbacks and script execution.
Paint & compositepaintCompositeRender
Painting pixels and assembling layers into the frames you see on screen.
Garbage collectiongarbageCollection
Reclaiming memory JavaScript no longer uses. A lot of it means allocation-heavy code.
Other browser work (scheduling)other
Chrome’s own task management: per-task overhead and thousands of sub-millisecond scheduler ticks — not page work you can attribute or optimize away. On this page 161 ms of it is this per-task bookkeeping (RunTask self time in the trace).

CPU time per script

Scripts by main-thread time

2 of 2 scripts

CPU time per moduleProfile run

Main-thread CPU time attributed to the individual modules inside concatenated JavaScript bundles (MediaWiki ResourceLoader), so a heavy bundle can be traced to the modules that actually cost the time.

The data comes from the extra profile run, not from the timed iterations.

ModuleVersionSelf time
jqueryxt2am111.7 ms
ext.wikimediaEventsqzzfn1.3 ms
mediawiki.storage3elpb1.1 ms
ext.testKitchen168ak0.9 ms
skins.vector.jssv4bp0.9 ms
ext.centralNotice.startUpei35p0.5 ms
ext.navigationTiming1u0am0.4 ms
(rest of the bundle, not tied to one module)142.2 ms
ModuleVersionSelf time
ext.visualEditor.supportCheck1ogmv0.1 ms
(rest of the bundle, not tied to one module)1.2 ms

Slowest JS functions

The functions where main-thread JavaScript time was actually spent, sampled by Chrome's JavaScript profiler. Self time is spent in the function itself; total time includes the functions it called. For loader/dispatcher functions whose total dwarfs their self time, the runs line shows the top functions and modules (up to five, ≥ 1 ms) the total was actually spent running.

Functions by self time

15 of 33 functions
FunctionWhereSelf timeTotal time
setAttributeBrowser internal (not your code)26.1 ms26.1 ms
flushWrites
runs: load.php[startup] (2.1 ms)
load.php[startup]17.7 ms19.9 ms
querySelectorAllBrowser internal (not your code)17.0 ms17.0 ms
appendChildBrowser internal (not your code)15.0 ms15.6 ms
getPropertyValueBrowser internal (not your code)12.9 ms12.9 ms
insertBeforeBrowser internal (not your code)9.4 ms9.4 ms
setTimeoutBrowser internal (not your code)7.5 ms7.5 ms
runScript
runs: load.php[scripts:ext.centralNotice.bannerHistoryLogger] (45.1 ms)
load.php[startup]6.9 ms86.5 ms
require
runs: load.php[scripts:ext.centralNotice.bannerHistoryLogger] (1.1 ms)
load.php[startup]5.9 ms12.6 ms
find
runs: querySelectorAll (11.5 ms), load.php[scripts:ext.centralNotice.bannerHistoryLogger] (3.0 ms)
load.php[scripts:ext.centralNotice.bannerHistoryLogger]5.2 ms20.6 ms
buildFragment
runs: appendChild (9.8 ms)
load.php[scripts:ext.centralNotice.bannerHistoryLogger]3.9 ms15.0 ms
requestIdleCallbackBrowser internal (not your code)3.6 ms3.6 ms
scrollToActiveSectionload.php[scripts:ext.centralNotice.bannerHistoryLogger]3.5 ms3.5 ms
doPropagation
runs: load.php[startup] (42.9 ms), load.php[scripts:ext.centralNotice.bannerHistoryLogger] (1.0 ms)
load.php[startup]3.3 ms47.5 ms
each
runs: load.php[scripts:ext.centralNotice.bannerHistoryLogger] (79.6 ms)
load.php[scripts:ext.centralNotice.bannerHistoryLogger]3.3 ms85.7 ms

TimersProfile run

How much setTimeout/setInterval work the page runs, credited to the script that scheduled each timer. Many zero-delay timers mean work sliced into a machine-gun of tiny tasks; repeating timers are polling.

Timers set53
Times fired51
Fire time124 ms
Zero-delay timers47
Repeating timers0
Zero-delay slicing: jquery split work into 45 back-to-back tasks costing 122 ms. Consider batching the work or moving it to requestIdleCallback or a worker.

Timer cost by script

2 scripts
load.php[scripts:ext.centralNotice.bannerHistoryLogger]
106 ms · set 52 times · fired 32 times
load.php[startup]
18 ms · set 1 time · fired 19 times

The timers, by where they were set

top 8 by fire time
Set byDelayTypeTimes setTimes firedFire time
jquery0 msonce4545121.5 ms
sendEvent in ext.testKitchen5000 msonce110.8 ms
SafeStorage in mediawiki.storage2000 msonce220.6 ms
jquery0 msonce110.6 ms
ext.navigationTiming0 msonce110.5 ms
requestUpdate in load.php[startup]:222000 msonce110.1 ms
run in ext.wikimediaEvents60000 msonce100.0 ms
setActive in ext.wikimediaEvents100000 msonce100.0 ms

Forced reflows

A forced reflow happens when JavaScript reads a layout-triggering property (offsetTop, getBoundingClientRect, …) inside a handler, forcing the browser to synchronously recompute layout. The scripts below caused most of the page's reflows. Fix them in priority order.

Scripts causing reflows

2 reflows ≥ 2 ms across 2 scripts
load.php[startup]
12 ms · 1 reflow · worst 12 ms

Forced layout per script

Each long animation frame reports how much time each script spent forcing synchronous style and layout, i.e. JavaScript reading layout-triggering properties mid-execution. Same actionable answer as forced reflows above but measured directly by the browser instead of inferred from the trace.

Scripts forcing layout

1 of 1 script
load.php[startup]
12 ms · across 1 frame

First vs third party CPU time

Main-thread CPU time from the Chrome trace split by domain. First party is wikipedia.org.

First party265 ms
Third party0 ms
Domains1

Want to dig deeper? Download the Chrome trace and drag-and-drop it into Performance in DevTools.