Run 1 summary

https://it.wikipedia.org/wiki/Rai

Tested 2026-09-20 14:45:26 using Chrome 152.0.7977.64 (runtime settings)

SummaryWaterfallMetricsRenderingCoachPageXrayCPU

Summary

Google Web Vitals

404 msTTFB
1.340 sLargest Contentful Paint
0.011Cumulative Layout Shift
1.541 sTotal Blocking Time

Loading

968 msFirst Paint
4.713 sFully Loaded
478 msMax Potential FID

Page weight & requests

869.8 KBTotal transfer size
2.9 MBTotal content size
35Requests

CPU

13Long tasks
4.236 sLast long task at

Visual progress

967 msFirst Visual Change
2.532 sSpeed Index
4.733 sVisual Complete 85%
4.767 sVisual Complete 99%
4.767 sLast Visual Change
Screenshot
Run 1 · after page complete

Waterfall

First paintFCPLCPDOMContentLoadedDOM interactiveLoadRender-blockingRedirectError

Rendering

Run 1
0.000 s
0s1s2s3s4s5s

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

25 frames

Use --filmstrip.showAll to show all filmstrips.

Frame at 0 ms
0 ms
0 %
Frame at 800 ms
800 ms
0 %
Frame at 900 ms
900 ms
0 %
Frame at 1.000 s
1.000 s
16 %
Frame at 1.200 s
1.200 s
17 %
Frame at 1.400 s
1.400 s
57 %
Frame at 1.500 s
1.500 s
57 %
Frame at 1.600 s
1.600 s
58 %
Frame at 1.900 s
1.900 s
60 %
Frame at 2.000 s
2.000 s
63 %
Frame at 2.100 s
2.100 s
63 %
Frame at 2.200 s
2.200 s
63 %
Frame at 2.500 s
2.500 s
63 %
Frame at 2.600 s
2.600 s
62 %
Frame at 2.700 s
2.700 s
62 %
Frame at 2.800 s
2.800 s
62 %
Frame at 2.900 s
2.900 s
62 %
Frame at 3.300 s
3.300 s
62 %
Frame at 3.800 s
3.800 s
62 %
Frame at 4.000 s
4.000 s
63 %
Frame at 4.200 s
4.200 s
61 %
Frame at 4.300 s
4.300 s
72 %
Frame at 4.600 s
4.600 s
72 %
Frame at 4.700 s
4.700 s
80 %
Frame at 4.800 s
4.800 s
100 %

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

Visual instability

99.93 % of pixels ever changed · 6.04 % 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 shown47
Partial9
Dropped11
Effective FPS11.8
Longest gap1.373 sat 2.585 s

Why was rendering delayed?

Rendering was not meaningfully delayed. First paint landed at 968 ms on a 404 ms first byte; the 2 render-blocking requests were done by 731 ms and the remaining ~237 ms is style and layout work (49 ms of it measured style recalculation). The largest paint followed at 1.340 s.

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).

Style recalculation is not holding up your paint. 49 ms of restyling before the page painted, 5 % of the time to First Contentful Paint. Nothing here needs attention.

Before first contentful paint

Recalculations3
Elements94
Total time48.859 ms
Largest recalculation92 elements · 46.652 ms

Before largest contentful paint

Recalculations14
Elements336
Total time104.111 ms
Largest recalculation197 elements · 46.652 ms

The recalculation work before first paint is 5 % of the time to First Contentful Paint.

Render blocking requests

3 requests · 46.1 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 dashed line is FCP, the clock ends at LCP); the gap after the bars is style and layout work.

RequestWhen it loadedTransferDownload
document
it.wikipedia.org · TTFB 404 ms
721 ms
149.5 KB721 ms
ext.cite.parsoid.styles + 14 more modulesblocking
css · load.php styles batch · it.wikipedia.org
274 ms
22.8 KB274 ms
site.stylesblocking
css · load.php styles batch · it.wikipedia.org
272 ms
1.1 KB272 ms
startuppotentially blocking
javascript · load.php startup · it.wikipedia.org
293 ms
22.2 KB293 ms
0335 ms670 msFCP 968 msLCP 1.340 s

Style invalidations

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. 598 style recalculations and 1 113 layout invalidations fired after first paint, on a page the user was already looking at. The biggest driver is pseudo has (122×). Start with the script under "Scripts causing invalidations" that keeps triggering it.

Style recalculations603598 after first paint
Layout invalidations1 2301 113 after first paint

Changes that keep invalidating

top 15
  • pseudo: has122×
  • attribute: title100×
  • class: mf-collapsible-heading58×
  • class: mf-collapsible-content29×
  • pseudo: disabled
  • pseudo: enabled
  • attribute: disabled
  • attribute: style
  • class: content
  • class: touch-events
  • attribute: href
  • pseudo: visited
  • class: minerva-animations-ready
  • class: page-actions-menu__list-item
  • class: cdx-button

Invalidation reasons

split at first paint

Between first and largest paint

Invalidations while the largest paint was still pending, so these delayed it.

ReasonStyle recalculationsLayout
A node was inserted into the page24
An element entered layout389
An element left layout1
An element's size changed3
Unknown3

After the largest paint

Churn on the fully rendered page: wasted work and possible jank, but no paint delay.

ReasonStyle recalculationsLayout
Related style rule177
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.173
A node was inserted into the page115
A stylesheet rule changed76
Attribute29
A pseudo-class state changed (:hover, :focus, …)2
JavaScript changed an inline styleSet a class instead of writing element.style, so the browser can batch the work.1
An animation updated stylesAnimate transform and opacity so the compositor can run it off the main thread.1
An element entered layout602
An element left layout66
A style change forced layout24
An element's size changed14
Unknown9
An SVG element changed2

Before first paint: building the page

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

ReasonStyle recalculationsLayout
A node was inserted into the page4
A stylesheet rule changed1
An element entered layout110
An element left layout3
An element's size changed1
Unknown3

Scripts causing invalidations

top 2

1 animation runs on the main thread instead of on the browser's fast path that animates without blocking other page work (the compositor); they can make the rendering you see above janky. See them on the CPU tab.

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

84
9 warnings2 info
warn(0)Avoid CPU Long TaskslongTasks

The page has 13 CPU long tasks with the total of 2.263 s. The total blocking time is 1.541 s and 2 long tasks before first contentful paint with total time of 172 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
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
warn(0)Serve images in modern formats (AVIF, WebP)modernImageFormats

The page ships 207 images (out of 207) 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
warn(0)Total JavaScript size shouldn't be too bigjavascriptSize

The total JavaScript transfer size is 415.9 kB and the uncompressed size is 1.6 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://it.wikipedia.org/w/load.php?lang=it&modules=startup&only=scripts&raw=1&skin=minerva22.2 KB67.2 KB
https://it.wikipedia.org/w/load.php...ia.org/w/load.php3.5 KB6.8 KB
https://it.wikipedia.org/w/load.php...ia.org/w/load.php9.4 KB26.9 KB
https://it.wikipedia.org/w/load.php...ia.org/w/load.php367.0 KB1.4 MB
https://auth.wikimedia.org/metawiki/wiki/Special:CentralAutoLogin/checkLoggedIn...gin/checkLoggedIn1.5 KB254 B
https://meta.wikimedia.org/w/index.php...a.org/w/index.php2.6 KB5.2 KB
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
warn(70)Don't use private headers on static contentprivateAssets

The page has 4 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
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(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(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.

infoAdd decoding="async" to non-critical imagesdecodingAsync

The page has 6 images (out of 211) 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(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://it.wikipedia.org/w/load.php?lang=it&modules=startup&only=scripts&raw=1&skin=minerva

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

80
4 info
infoGive every image a textual alternativeimageAltText

The page has 165 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
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 24 responses that sets both a max-age and expires header. There are 35 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
infoDo not send too long headerslongHeaders

https://it.wikipedia.org/wiki/Rai has a header content-security-policy that is 4541 characters long. https://it.wikipedia...ia.org/w/load.php has a header sourcemap that is 1459 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.

TitleRai - WikipediaThe document title, shown in the browser tab and used by search results.
GeneratorMediaWiki 1.47.0-wmf.20The tool or CMS that generated the HTML, from the page generator meta tag.
Layout viewport361 × 4881 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 elements8,518Very large, slows layout and styleTotal HTML elements. Fewer means less for the browser to style, lay out and paint.
Avg DOM depth15How deeply elements are nested on average.
Max DOM depth23The deepest nesting on the page. Deep branches cost more style recalculation.
Iframes0No embedded documents on this page.
Script tags7Number 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 storage899.5 KBData the page saved in localStorage, kept across visits.
Session storage0 bData kept in sessionStorage for this tab session only.
Connection type4GWhat the Network Information API reported for the test connection.

Resource hints

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

Visual Metrics

Visual milestones

all times from navigation start
Speed Index2.53 show quickly the page looked done
First Visual Change0.97 sfirst paint reaches the screen
Last Visual Change4.77 sscreen stops changing · 3.80 s after first
nothing painted yet
0.97 sFirst Visual Change
Visual Complete 85% · Visual Complete 95% · Visual Complete 99% · Last Visual Change4.73 s
Visual Readiness3.80 s· first to last change
01.0 s2.0 s3.0 s4.0 s
Visual progress
Visual progress at 0 s0.0s
Visual progress at 1 s1.0s
Visual progress at 1.6 s1.6s
Visual progress at 2.1 s2.1s
Visual progress at 2.7 s2.7s
Visual progress at 3.3 s3.3s
Visual progress at 4.3 s4.3s
Visual progress at 4.8 s4.8s
FCP0.97s
LCP1.34s
VC854.73s
Long tasks
0.0s1.0s1.9s2.9s3.8s4.8s

Google Web Vitals

Largest Contentful Paint

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

1.340 sLCP render time

Phase breakdown

  • TTFB404 ms
  • Resource load delay0 ms
  • Resource load duration0 ms
  • Element render delay936 ms

Element

Element type
<p>
Element id
mwFQ
Size (w × h)
55968
Load time
0 ms
Style recalculation before LCP
14 recalculations touching 336 elements (104.111 ms) — the largest touched 197 elements (46.652 ms)

DOM path

body > div#mw-mf-viewport > div#mw-mf-page-center > main#content > div#bodyContent > div#mw-content-text > div:eq(0) > section#mwAQ > p#mwFQ
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.

0.011cumulative layout shift score

One shift is 100% of your 0.011 CLS. div#bodyContent moved at 2.557 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.

  • 0.011
    100% of CLSshifted at 2.557 s
    <div id="bodyContent" class="content">
    body > div#mw-mf-viewport > div#mw-mf-page-center > main#content > div#bodyContent
    <div class="pre-content heading-holder">
    body > div#mw-mf-viewport > div#mw-mf-page-center > main#content > div:eq(1)
    <ul id="p-views" class="page-actions-menu__list minerva-icon-only-menu">
    body > div#mw-mf-viewport > div#mw-mf-page-center > main#content > div:eq(1) > nav > ul#p-views
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
mwStartup1.120 s
mwCentralNoticeBanner4.153 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 ms2827151137

Custom metrics collected through JavaScript

There are no custom configured scripts.

Extra metrics collected using scripting

There are no custom extra metrics from scripting.

Chrome internal metrics (CDP)33
Audio handlers0
Audio worklet processors0
Documents45
Frames26
JS event listeners748
Layout objects1113
Media key sessions0
Media keys0
Nodes17502
Resources170
Context lifecycle state observers65
V8 per context datas3
Worker global scopes0
Uacss resources0
Rtc peer connections0
Resource fetchers45
Ad subframes0
Detached script states2
Array buffer contents4
Layout count17
Recalc style count21
Layout duration168
Recalc style duration349
Dev tools command duration996
Script duration1762
V8 compile duration19
Task duration4808
Task other duration1514
Thread time12
Process time15
JS heap used size10897020
JS heap total size14077952
First meaningful paint1339
Visual Elements3
LargestImagewikipedia-wordmark-en.svg
Display time967 ms
Position (x, y)53, 18
Size (w × h)120 × 18
HTML snippet
<img src="/static/images/mobile/copyright/wikipedia-wordmark-en.svg" alt="Wikipedia" width="120" height="18" style="width: 7.5em; height: 1.125em;">
Heading
Display time4.233 s
Position (x, y)16, 220
Size (w × h)328 × 37
HTML snippet
<h1 id="firstHeading" class="firstHeading mw-first-heading"></h1>
LargestContentfulPaint
Display time4.600 s
Position (x, y)16, 398
Size (w × h)328 × 185
HTML snippet
<p id="mwFQ"></p>

PageXray

How the page is built.

HTTP versionHTTP/2.0
Total requests35
Total domains5
Transfer size869.8 KB
Content size2.9 MB
Missing compression0
Cookies140 third-party

Main document

status 200 · 0 redirects

https://it.wikipedia.org/wiki/Rai

HeaderValue
accept-ch
accept-rangesbytes
age2395
cache-controlprivate, s-maxage=0, max-age=0, must-revalidate, no-transform
content-encodinggzip
content-languageit
content-length146833
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 thumb.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 thumb.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
dateSun, 20 Sep 2026 14:05:33 GMT
last-modifiedSun, 20 Sep 2026 11:09:31 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-5f96df4694-gdncs
server-timingcache;desc="hit-front", host;desc="cp3070",co_id;desc="2827151137"
strict-transport-securitymax-age=106384710; includeSubDomains; preload
varyAccept-Encoding,X-Subdomain,Cookie,Authorization,User-Agent
x-analytics
x-cachecp3070 miss, cp3070 hit/2
x-cache-statushit-front
x-client-ip138.201.135.103
x-content-type-optionsnosniff
x-request-ida2bbe3d3-8d54-4a8b-a5b4-e1f34361aaea

Response codes

200
3497.1%
302
12.9%

Requests and sizes per content type

7 types

Transfer size869.8 KB

  • javascript46.7%
  • image30.7%
  • html17.2%
  • css2.7%
  • svg2.3%
  • favicon0.21%
  • json0.21%

Content size2.9 MB

  • javascript53.7%
  • html31.3%
  • image8.6%
  • css5.9%
  • svg0.37%
  • favicon0.09%
  • json0.01%

Requests34

  • svg44.1%
  • image23.5%
  • javascript17.6%
  • css5.9%
  • html2.9%
  • favicon2.9%
  • json2.9%
ContentHeader SizeTransfer SizeContent SizeRequests
html0 b149.5 KB920.4 KB1
css0 b23.9 KB173.5 KB2
javascript0 b406.2 KB1.5 MB6
image0 b267.0 KB252.7 KB8
favicon0 b1.8 KB2.7 KB1
svg0 b19.6 KB10.9 KB15
json0 b1.8 KB296 B1
Total0 b869.8 KB2.9 MB34

Data per domain

5 domains
DomainTotal download timeTransfer SizeContent SizeRequests
it.wikipedia.org5.481 s600.8 KB2.6 MB26
thumb.wikimedia.org1.466 s213.3 KB205.3 KB4
auth.wikimedia.org186 ms1.5 KB254 B1
meta.wikimedia.org101 ms2.6 KB5.2 KB1
upload.wikimedia.org1.562 s51.6 KB46.1 KB3

Expires & last-modified statistics

typeminmedianmax
Expires0 seconds4 weeks1 year
Last modified3 hours7 weeks2 years

Console log

1 message

The page logs the following messages to the console.

LevelMessage
INFOhttps://it.wikipedia.org/w/load.php?lang=it&modules=%40wikimedia%2Fcodex%2Ccodex-styles%2Cjquery%2Coojs%2Csite%2Cvue%7Cext.centralNotice.choiceData%2Cdisplay%2CgeoIP%2CimpressionDiet%2CkvStore%2CstartUp%7Cext.centralauth.ForeignApi%2Ccentralautologin%7Cext.checkUser.clientHints%7Cext.cite.ux-enhancements%7Cext.cx.entrypoints.languagesearcher.v2%7Cext.cx.eventlogging.campaigns%7Cext.cx.model%7Cext.dismissableSiteNotice%2CeventLogging%2CnavigationTiming%2Cpopups%2CtestKitchen%2CwikimediaEvents%7Cext.echo.centralauth%7Cext.eventLogging.metricsPlatform%7Cext.quicksurveys.init%2Clib%7Cext.relatedArticles.readMore.bootstrap%7Cext.uls.interface%2Cpreferences%2Cwebfonts%7Cext.uls.rewrite.entrypoints%7Cext.urlShortener.toolbar%7Cext.wikimediaCustomizations.donor%2CdonorAccountCreation%7Cext.wikimediaEvents.testKitchen%7Cjquery.client%2Cspinner%2Ctablesorter%2CtextSelection%7Cjquery.spinner.styles%7Cjquery.uls.data%7Cmediawiki.DateFormatter%2CForeignApi%2CString%2CTitle%2Capi%2Cbase%2Ccldr%2Ccookie%2Cexperiments%2CjqueryMsg%2Clanguage%2Crouter%2Cstorage%2Ctemplate%2Cuser%2Cutil%2CvisibleTimeout%7Cmediawiki.ForeignApi.core%7Cmediawiki.language.months%7Cmediawiki.libs.pluralruleparser%7Cmediawiki.page.media%2Cready%7Cmediawiki.page.watch.ajax%7Cmediawiki.template.mustache%7Cmmv.bootstrap%7Cmobile.codex.styles%7Cmobile.init%2Cstartup%7Cmw.cx.SiteMapper%7Cmw.externalguidance.init%7Cskins.minerva.scripts%7Cwikibase.databox.fromWikidata&skin=minerva&version=jez1a 859:13527 "Learn more about how we build our mobile site @ https://www.mediawiki.org/wiki/Special:MyLanguage/Extension:MobileFrontend"

Requests loaded after onLoad event

8 requests

Includes requests done after load event end.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript4.1 KB2
image53.7 KB4
font0 b0
favicon1.8 KB1
Total59.6 KB8

Requests loaded after onContentLoad

8 requests

Includes requests done after DOM content loaded.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript4.1 KB2
image53.7 KB4
font0 b0
favicon1.8 KB1
Total59.6 KB8

CPU

load.php[startup] is responsible for 69% of blocking time
956 ms of 1386 ms total. Defer it, replace it with a lighter alternative, or move its work off the main thread to recover most of your TBT.

Long tasks

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

TBT1.541 s
Max potential input delay478 ms
Total long tasks13
Total time2.263 s
Last task at4.236 s
Before first paint172 ms2 tasks
Before FCP172 ms2 tasks
Before LCP172 ms2 tasks
After load1.841 s10 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 frames14showing the 10 with the most blocking time
Blocking time1.853 sacross all long frames — what hurts INP and TBT
Forced style & layout68.1 msscripts reading layout mid-frame
Blocking before LCP149.2 msdelaying the largest paint — fix these first
Blocking after load1.416 safter 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]41.073 s956.4 ms68.1 mstimer or animation callback
load.php[scripts:@wikimedia/codex]4600.3 ms428.1 mstimer or animation callback
Rai19.9 ms1.3 msscript tag

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 · 535.1 msat 3.196 s · after load
blocking 419.9 ms
  • Scripts & other work76.9 ms
  • Animation callbacks399.1 ms
  • Style & layout59.1 ms
  • Render0 ms
5 scripts ran during this frame · forced style & layout 68.1 ms
Ran for
9.3 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 419859 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Ran for
10.6 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 419859 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Ran for
11.7 ms
Started by
IdleRequestCallback
How it started
timer or animation callback
Source function
doPropagation
Position in source
character 4301 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Ran for
11.2 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 419859 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Ran for
396.7 ms
Forced style and layout
68.1 ms
Started by
FrameRequestCallback
How it started
timer or animation callback
Source function
flushCssBuffer
Position in source
character 3227 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Long animation frame #2 · 422 msat 2.135 s · after load
blocking 370.6 ms
  • Scripts & other work278.6 ms
  • Animation callbacks103 ms
  • Style & layout40.4 ms
  • Render0 ms
2 scripts ran during this frame
Ran for
277.1 ms
Started by
IdleRequestCallback
How it started
timer or animation callback
Source function
doPropagation
Position in source
character 4301 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Ran for
102.9 ms
Started by
FrameRequestCallback
How it started
timer or animation callback
Source function
flushCssBuffer
Position in source
character 3227 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Long animation frame #3 · 397.9 msat 2.789 s · after load
blocking 306.3 ms
  • Scripts & other work393.2 ms
  • Animation callbacks4.6 ms
  • Style & layout0.1 ms
  • Render0 ms
2 scripts ran during this frame
Ran for
21.8 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 419859 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Ran for
351.6 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 419859 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Long animation frame #4 · 372.4 msat 1.552 s · before load
blocking 288 ms
  • Scripts & other work284.9 ms
  • Animation callbacks0 ms
  • Style & layout87.5 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 #5 · 191.9 msat 3.752 s · after load
blocking 120.4 ms
  • Scripts & other work164.6 ms
  • Animation callbacks27.1 ms
  • Style & layout0.2 ms
  • Render0 ms
1 script ran during this frame
Ran for
143.1 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 419859 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Long animation frame #6 · 151.3 msat 2.626 s · after load
blocking 99.3 ms
  • Scripts & other work95.9 ms
  • Animation callbacks45.2 ms
  • Style & layout10.2 ms
  • Render0 ms
2 scripts ran during this frame
Ran for
93.9 ms
Started by
IdleRequestCallback
How it started
timer or animation callback
Source function
doPropagation
Position in source
character 4301 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Ran for
44 ms
Started by
FrameRequestCallback
How it started
timer or animation callback
Source function
flushCssBuffer
Position in source
character 3227 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Long animation frame #7 · 146.4 msat 4.236 s · after load
blocking 96.4 ms
  • Scripts & other work146.4 ms
  • Animation callbacks0 ms
  • Style & layout0 ms
  • Render0 ms
1 script ran during this frame
Ran for
146.3 ms
Started by
IdleRequestCallback
How it started
timer or animation callback
Source function
flushWrites
Position in source
character 19327 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Long animation frame #8 · 147 msat 1.168 s · before LCP
blocking 86.8 ms
  • Scripts & other work21.9 ms
  • Animation callbacks0 ms
  • Style & layout125.1 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 #9 · 472.7 msat 472.8 ms · before LCP
blocking 62.4 ms
  • Scripts & other work470.7 ms
  • Animation callbacks1.4 ms
  • Style & layout0.6 ms
  • Render0 ms
1 script ran during this frame
Ran for
9.9 ms
Queued before running
3.1 ms
How it started
script tag
Long animation frame #10 · 52.8 msat 3.973 s · after load
blocking 2.8 ms
  • Scripts & other work52.8 ms
  • Animation callbacks0 ms
  • Style & layout0 ms
  • Render0 ms
1 script ran during this frame
Ran for
52.7 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 419859 into the file (locate it via DevTools → Performance → the Long Animation Frames track)

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

3 of 3 scripts
load.php[startup]
956 ms · 7 frames · worst 379 ms
load.php[scripts:@wikimedia/codex]
428 ms · 7 frames · worst 274 ms
https://it.wikipedia.org/wiki/Rai
1 ms · 1 frame · worst 1 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.

TBT1.915 s
Blocking tasks19
TBT before LCP183.4 ms5 tasks

What kind of work blocked

mostly running javascript · 1.915 s total
Running JavaScript1.221 s63.7%
Style & layout307.9 ms16.1%
Parsing HTML & CSS230.1 ms12.0%
Paint & composite81.7 ms4.3%
Other browser work54.0 ms2.8%
Garbage collection20.1 ms1.0%
Parsing & compiling JavaScript0.9 ms0.0%
Running JavaScript (64%): the scripts responsible are listed right below. See Slowest JS functions · Timers
Style & layout (16%): usually a large DOM, expensive CSS selectors or JavaScript forcing synchronous layout. See Forced reflows · Forced layout per script · Style invalidations (Rendering tab)
Parsing HTML & CSS (12%): reading the HTML document. A smaller document parses faster.

Top scripts blocking the main thread

4 of 4 scripts
load.php[startup]
935 ms · 7 tasks
Browser's own work (no script responsible)
361 ms · 6 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

4.114 s total
Running JavaScript2.000 s48.6%
Other browser work (scheduling)701 ms17.0%
Parsing HTML & CSS604 ms14.7%
Style & layout546 ms13.3%
Paint & composite211 ms5.1%
Garbage collection27 ms0.7%
Parsing & compiling JavaScript25 ms0.6%
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 693 ms of it is this per-task bookkeeping (RunTask self time in the trace).

CPU time per script

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 50 functions
FunctionWhereSelf timeTotal time
flushWrites
runs: load.php[startup] (20.1 ms)
load.php[startup]120.3 ms140.3 ms
querySelectorAllBrowser internal (not your code)101.6 ms101.6 ms
setAttributeBrowser internal (not your code)92.7 ms92.7 ms
(anonymous)
runs: after (42.3 ms), setAttribute (1.5 ms), appendChild (1.3 ms)
load.php[scripts:@wikimedia/codex]83.6 ms128.8 ms
runScript
runs: load.php[scripts:@wikimedia/codex] (556.2 ms)
load.php[startup]76.3 ms829.3 ms
insertBeforeBrowser internal (not your code)71.9 ms71.9 ms
(anonymous)load.php[scripts:@wikimedia/codex]68.4 ms68.4 ms
find
runs: querySelectorAll (90.9 ms), load.php[scripts:@wikimedia/codex] (18.1 ms), getElementsByClassName (1.4 ms)
load.php[scripts:@wikimedia/codex]49.3 ms160.6 ms
require
runs: load.php[scripts:@wikimedia/codex] (52.2 ms), load.php[startup] (8.6 ms)
load.php[startup]49.0 ms119.1 ms
afterBrowser internal (not your code)42.3 ms42.3 ms
setTimeoutBrowser internal (not your code)37.9 ms37.9 ms
impl
runs: load.php[scripts:@wikimedia/codex] (1.4 ms), load.php[startup] (1.3 ms), load.php[scripts:ext.gadget.HiddenCat] (1.1 ms)
load.php[startup]35.8 ms41.6 ms
doPropagation
runs: load.php[startup] (349.8 ms)
load.php[startup]28.5 ms379.0 ms
parseImageUrl
runs: RegExp: \/[\da-f]\/[\da-f]{2}\/([^\s/]+)\/(?:[^\s/]+-)?(\d+)px-(?:\1|thumbnail|[a-z\d]{31})(?:\.[^\s/?]+)?(?:\?[^\s]+)?$ (3.0 ms)
load.php[scripts:@wikimedia/codex]28.3 ms31.2 ms
resources/lib/vue/vue.js
runs: load.php[scripts:@wikimedia/codex] (13.7 ms)
load.php[scripts:@wikimedia/codex]24.7 ms38.3 ms

Timers

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 set62
Times fired60
Fire time688.2 ms
Zero-delay timers57
Repeating timers0
Zero-delay slicing: load.php[scripts:@wikimedia/codex] split work into 55 back-to-back tasks costing 672 ms. Consider batching the work or moving it to requestIdleCallback or a worker.

Timer cost by script

3 scripts
load.php[scripts:@wikimedia/codex]
496 ms · set 61 times · fired 46 times
load.php[startup]
179 ms · set 1 time · fired 13 times

The timers, by where they were set

top 7 by fire time

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 1 script
load.php[startup]
68 ms · 2 reflows · worst 64 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]
68 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 party1.916 s
Third party3 ms
Domains1

Non-composited animations

Animations that fell back from the compositor to the main thread, blocking each frame instead of running on the GPU.

Why they could not be composited

1 animation
  • animation has no visible change

The reason decides the action: “animation has no visible change” means Chrome skipped compositing because nothing visible moves — harmless. Property-related reasons mean the keyframes animate something other than transform or opacity.

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