Run 2 summary

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

Tested 2026-08-24 23:25:31 using Chrome 151.0.7922.75 (runtime settings)

SummaryWaterfallMetricsRenderingCoachPageXrayCPU

Summary

Google Web Vitals

404 msTTFB
1.516 sLargest Contentful Paint
0.000Cumulative Layout Shift
925 msTotal Blocking Time

Loading

1.012 sFirst Paint
3.279 sFully Loaded
244 msMax Potential FID

Page weight & requests

660.7 KBTotal transfer size
2.4 MBTotal content size
37Requests

CPU

13Long tasks
4.313 sLast long task at

Visual progress

1.000 sFirst Visual Change
1.199 sSpeed Index
1.500 sVisual Complete 85%
3.567 sVisual Complete 99%
3.567 sLast Visual Change
Screenshot
Run 2 · after page complete

Waterfall

First paintFCPLCPDOMContentLoadedDOM interactiveLoadRender-blockingRedirectError

Rendering

Run 2
0.000 s
0s1s2s3s

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

19 frames

Use --filmstrip.showAll to show all filmstrips.

Frame at 0 ms
0 ms
0 %
Frame at 700 ms
700 ms
0 %
Frame at 800 ms
800 ms
0 %
Frame at 1.000 s
1.000 s
61 %
Frame at 1.100 s
1.100 s
61 %
Frame at 1.400 s
1.400 s
83 %
Frame at 1.500 s
1.500 s
98 %
Frame at 1.600 s
1.600 s
98 %
Frame at 1.700 s
1.700 s
98 %
Frame at 2.200 s
2.200 s
98 %
Frame at 2.300 s
2.300 s
98 %
Frame at 2.500 s
2.500 s
98 %
Frame at 2.700 s
2.700 s
98 %
Frame at 2.800 s
2.800 s
98 %
Frame at 2.900 s
2.900 s
98 %
Frame at 3.200 s
3.200 s
98 %
Frame at 3.300 s
3.300 s
98 %
Frame at 3.500 s
3.500 s
98 %
Frame at 3.600 s
3.600 s
100 %

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

Visual instability

42.39 % 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 shown25
Partial18
Dropped9
Effective FPS9.4
Longest gap1.889 sat 1.656 s

Why was rendering delayed?

Rendering was not meaningfully delayed. First paint landed at 1.012 s on a 404 ms first byte; the 2 render-blocking requests were done by 678 ms and the remaining ~334 ms is style and layout work (105 ms of it measured style recalculation). The largest paint followed at 1.516 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).

One large recalculation dominates. Restyling 564 elements cost 105 ms before the page painted (10.4 % of the time to First Contentful Paint), and a single recalculation of 561 elements accounts for 103 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 contentful paint

Recalculations4
Elements564
Total time105.354 ms
Largest recalculation561 elements · 102.853 ms

Before largest contentful paint

Recalculations20
Elements693
Total time162.571 ms
Largest recalculation561 elements · 102.853 ms

The recalculation work before first paint is 10.4 % of the time to First Contentful Paint.

Render blocking requests

3 requests · 45.2 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
627 ms
91.1 KB626 ms
site.stylesblocking
css · load.php styles batch · it.wikipedia.org
219 ms
1.1 KB219 ms
ext.cite.parsoid.styles + 13 more modulesblocking
css · load.php styles batch · it.wikipedia.org
201 ms
22.1 KB201 ms
startuppotentially blocking
javascript · load.php startup · it.wikipedia.org
230 ms
22.0 KB230 ms
LCP resource
500px-Jannik_Sinner_US_Open_2025_%28cropped%29.jpg — downloaded by 1.338 s, rendered at 1.516 s
340 ms
96.4 KB340 ms
0379 ms758 msFCP 1.012 sLCP 1.516 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. 324 style recalculations and 321 layout invalidations fired after first paint, on a page the user was already looking at. The biggest driver is attribute title (152×). Start with the script under "Scripts causing invalidations" that keeps triggering it.

Style recalculations330324 after first paint
Layout invalidations1 173321 after first paint

Changes that keep invalidating

top 15
  • attribute: title152×
  • pseudo: has44×
  • class: mf-collapsible-heading22×
  • class: mf-collapsible-content11×
  • pseudo: disabled
  • pseudo: enabled
  • pseudo: last-child
  • pseudo: only-child
  • attribute: disabled
  • class: content
  • class: touch-events
  • attribute: href
  • pseudo: visited
  • class: minerva-animations-ready
  • class: page-actions-menu__list-item

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 page48
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.23
An element entered layout153
An element's size changed19
Unknown9
An SVG element changed1

After the largest paint

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

ReasonStyle recalculationsLayout
A node was inserted into the page51
Related style rule85
A stylesheet rule changed77
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.28
Attribute11
An animation updated stylesAnimate transform and opacity so the compositor can run it off the main thread.1
An element entered layout93
An element left layout29
An element's size changed3
Unknown3
An SVG element changed6
A style change forced layout5

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
A pseudo-class state changed (:hover, :focus, …)1
An element entered layout845
An element left layout3
An element's size changed1
Unknown3

Scripts causing invalidations

top 1

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

82
11 warnings2 info
warn(0)Avoid CPU Long TaskslongTasks

The page has 13 CPU long tasks with the total of 1.812 s. The total blocking time is 925 ms and 2 long tasks before first contentful paint with total time of 337 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 63 images (out of 63) 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 12 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 125.7 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 409.3 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=minerva22.0 KB66.5 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 KB27.0 KB
https://it.wikipedia.org/w/load.php...ia.org/w/load.php363.4 KB1.5 MB
https://auth.wikimedia.org/metawiki/wiki/Special:CentralAutoLogin/checkLoggedIn...gin/checkLoggedIn1.5 KB254 B
warn(10)Apply the right priority hints to the LCP imagelcpImageHints

The LCP image has loading="lazy", which delays its download until the browser thinks it is near the viewport — and so directly delays the LCP metric. Remove loading="lazy" from the LCP image. The LCP image is missing fetchpriority="high". Adding it tells the browser to fetch the image with high priority instead of the default heuristic (which often deprioritises hero images that are loaded after the HTML has been parsed).

When the Largest Contentful Paint element is an image, the browser priority hints applied to that element directly affect the LCP metric. The image must NOT be loading="lazy" (that defers the fetch until near-viewport, which is the opposite of what an LCP image needs) and SHOULD be fetchpriority="high" (so the browser fetches it with high priority instead of guessing). https://web.dev/articles/fetch-priority

Offenders
  • <img resource="https://it.wikipedia.org/wiki/File:Jannik_Sinner_US_Open_2025_(cropped).jpg" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/48/Jannik_Sinner_US_Open_2025_%28cropped%29.jpg/250px-Jannik_Sinner_US_Open_2025_%28cropped%29.jpg?utm_source=it.wikipedia.org&amp;utm_campaign=parser&amp;utm_content=thumbnail" decoding="async" loading="lazy" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/48/Jannik_Sinner_US_Open_2025_%28cropped%29.jpg/500px-Jannik_Sinner_US_Open_2025_%28cropped%29.jpg?utm_source=it.wikipedia.org&amp;utm_campaign=parser&amp;utm_content=thumbnail 2x" data-file-width="1204" data-file-height="2000" data-file-type="bitmap" height="300" width="180" class="mw-file-element">
  • <img resource="https://it.wikipedia.org/wiki/File:Jannik_Sinner_US_Open_2025_(cropped).jpg" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/48/Jannik_Sinner_US_Open_2025_%28cropped%29.jpg/250px-Jannik_Sinner_US_Open_2025_%28cropped%29.jpg?utm_source=it.wikipedia.org&amp;utm_campaign=parser&amp;utm_content=thumbnail" decoding="async" loading="lazy" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/48/Jannik_Sinner_US_Open_2025_%28cropped%29.jpg/500px-Jannik_Sinner_US_Open_2025_%28cropped%29.jpg?utm_source=it.wikipedia.org&amp;utm_campaign=parser&amp;utm_content=thumbnail 2x" data-file-width="1204" data-file-height="2000" data-file-type="bitmap" height="300" width="180" class="mw-file-element">
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 scale images in the browseravoidScalingImages

The page has 2 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(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
infoAdd decoding="async" to non-critical imagesdecodingAsync

The page has 5 images (out of 67) 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(98)Lazy-load below-the-fold imageslazyLoadingImages

The page has 1 below-the-fold image 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(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 11 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 37 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...iki/Jannik_Sinner has a header content-security-policy that is 4501 characters long. https://it.wikipedia...ia.org/w/load.php has a header sourcemap that is 1342 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.

TitleJannik Sinner - WikipediaThe document title, shown in the browser tab and used by search results.
GeneratorMediaWiki 1.47.0-wmf.16The tool or CMS that generated the HTML, from the page generator meta tag.
Layout viewport360 × 4518 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 elements4,515Very large, slows layout and styleTotal HTML elements. Fewer means less for the browser to style, lay out and paint.
Avg DOM depth14How deeply elements are nested on average.
Max DOM depth21The 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 storage923.0 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://upload.wikimedia.org/

Technologies used to build the page

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

Detected technologies

4 technologies

Visual Metrics

Visual milestones

all times from navigation start
Speed Index1.20 show quickly the page looked done
First Visual Change1.00 sfirst paint reaches the screen
Last Visual Change3.57 sscreen stops changing · 2.57 s after first
nothing painted yet
≥95% rendered
First Visual Change1.00 s
1.50 sVisual Complete 85% · Visual Complete 95%
Visual Complete 99% · Last Visual Change3.57 s
Visual Readiness2.57 s· first to last change
01.0 s2.0 s3.0 s
Visual progress
Visual progress at 0 s0.0s
Visual progress at 1 s1.0s
Visual progress at 1.4 s1.4s
Visual progress at 1.7 s1.7s
Visual progress at 2.3 s2.3s
Visual progress at 2.8 s2.8s
Visual progress at 3.2 s3.2s
Visual progress at 3.6 s3.6s
FCP1.01s
LCP1.52s
VC851.50s
Long tasks
0.0s0.7s1.4s2.2s2.9s3.6s

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.

1.516 sLCP render time

Phase breakdown

  • TTFB404 ms
  • Resource load delay598 ms
  • Resource load duration341 ms
  • Element render delay173 ms

Element

Element type
<img>
Size (w × h)
54000
URL
https://upload.wikim...%28cropped%29.jpg
Load time
1.365 s
Style recalculation before LCP
20 recalculations touching 693 elements (162.571 ms) — the largest touched 561 elements (102.853 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 > table > tbody > tr:eq(1) > td > figure > a > img
LCP

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

The Largest Contentful Paint API matched this image:

LCP element

Cumulative Layout Shift

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

0.000cumulative layout shift score

No layout shifts were detected on this page.

Browser Metrics

Navigation Timing
Extra timings
User Timing marks
mwStartup1.659 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 ms2309320323

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 listeners290
Layout objects1103
Media key sessions0
Media keys0
Nodes9278
Resources58
Context lifecycle state observers66
V8 per context datas3
Worker global scopes0
Uacss resources0
Rtc peer connections0
Resource fetchers45
Ad subframes0
Detached script states2
Array buffer contents4
Layout count13
Recalc style count12
Layout duration133
Recalc style duration281
Dev tools command duration881
Script duration1329
V8 compile duration18
Task duration3803
Task other duration1161
Thread time10
Process time13
JS heap used size10514188
JS heap total size13103104
First meaningful paint1008
Visual Elements3
LargestImage250px-Jannik_Sinner_US_Open_2025_%28cropped%29.jpg?utm_source=it.wikipedia.org&utm_campaign=parser&utm_content=thumbnail
Display time3.567 s
Position (x, y)90, 312
Size (w × h)180 × 299
HTML snippet
<img resource="https://it.wikipedia.org/wiki/File:Jannik_Sinner_US_Open_2025_(cropped).jpg" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/48/Jannik_Sinner_US_Open_2025_%28cropped%29.jpg/250px-Jannik_Sinner_US_Open_2025_%28cropped%29.jpg?utm_source=it.wikipedia.org&amp;utm_campaign=parser&amp;utm_content=thumbnail" decoding="async" loading="lazy" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/48/Jannik_Sinner_US_Open_2025_%28cropped%29.jpg/500px-Jannik_Sinner_US_Open_2025_%28cropped%29.jpg?utm_source=it.wikipedia.org&amp;utm_campaign=parser&amp;utm_content=thumbnail 2x" data-file-width="1204" data-file-height="2000" data-file-type="bitmap" height="300" width="180" class="mw-file-element">
Heading
Display time1.000 s
Position (x, y)16, 75
Size (w × h)328 × 37
HTML snippet
<h1 id="firstHeading" class="firstHeading mw-first-heading"></h1>
LargestContentfulPaint250px-Jannik_Sinner_US_Open_2025_%28cropped%29.jpg?utm_source=it.wikipedia.org&utm_campaign=parser&utm_content=thumbnail
Display time3.567 s
Position (x, y)90, 312
Size (w × h)180 × 299
HTML snippet
<img resource="https://it.wikipedia.org/wiki/File:Jannik_Sinner_US_Open_2025_(cropped).jpg" src="//upload.wikimedia.org/wikipedia/commons/thumb/4/48/Jannik_Sinner_US_Open_2025_%28cropped%29.jpg/250px-Jannik_Sinner_US_Open_2025_%28cropped%29.jpg?utm_source=it.wikipedia.org&amp;utm_campaign=parser&amp;utm_content=thumbnail" decoding="async" loading="lazy" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/48/Jannik_Sinner_US_Open_2025_%28cropped%29.jpg/500px-Jannik_Sinner_US_Open_2025_%28cropped%29.jpg?utm_source=it.wikipedia.org&amp;utm_campaign=parser&amp;utm_content=thumbnail 2x" data-file-width="1204" data-file-height="2000" data-file-type="bitmap" height="300" width="180" class="mw-file-element">

PageXray

How the page is built.

HTTP versionHTTP/2.0
Total requests37
Total domains3
Transfer size660.7 KB
Content size2.4 MB
Missing compression0
Cookies160 third-party

Main document

status 200 · 0 redirects

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

HeaderValue
accept-ch
accept-rangesbytes
age12989
cache-controlprivate, s-maxage=0, max-age=0, must-revalidate, no-transform
content-encodinggzip
content-languageit
content-length87047
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content-typetext/html; charset=UTF-8
dateMon, 24 Aug 2026 19:49:03 GMT
last-modifiedMon, 24 Aug 2026 18:52:40 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-7f99bb786d-lrsst
server-timingcache;desc="hit-front", host;desc="cp3070",co_id;desc="2309320323"
strict-transport-securitymax-age=106384710; includeSubDomains; preload
varyAccept-Encoding,X-Subdomain,Cookie,Authorization,User-Agent
x-analytics
x-cachecp3070 miss, cp3070 hit/7
x-cache-statushit-front
x-client-ip138.201.135.103
x-content-type-optionsnosniff
x-request-id34a32353-613e-44e5-9151-4227cca0b83a

Response codes

200
3697.3%
302
12.7%

Requests and sizes per content type

7 types

Transfer size660.7 KB

  • javascript60.5%
  • image18.7%
  • html13.8%
  • css3.5%
  • svg3.0%
  • favicon0.27%
  • json0.27%

Content size2.4 MB

  • javascript65.3%
  • html23.0%
  • css6.9%
  • image4.3%
  • svg0.45%
  • favicon0.11%
  • json0.01%

Requests36

  • svg41.7%
  • image30.6%
  • javascript13.9%
  • css5.6%
  • html2.8%
  • favicon2.8%
  • json2.8%
ContentHeader SizeTransfer SizeContent SizeRequests
html0 b91.1 KB563.9 KB1
css0 b23.2 KB168.2 KB2
javascript0 b399.7 KB1.6 MB5
image0 b123.3 KB104.3 KB11
favicon0 b1.8 KB2.7 KB1
svg0 b19.7 KB11.0 KB15
json0 b1.8 KB296 B1
Total0 b660.7 KB2.4 MB36

Data per domain

3 domains
DomainTotal download timeTransfer SizeContent SizeRequests
it.wikipedia.org4.535 s537.9 KB2.3 MB26
upload.wikimedia.org3.416 s121.3 KB103.0 KB10
auth.wikimedia.org186 ms1.5 KB254 B1

Expires & last-modified statistics

typeminmedianmax
Expires0 seconds4 weeks1 year
Last modified56 minutes12 weeks13 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.echo.centralauth%7Cext.eventLogging%2CnavigationTiming%2Cpopups%2CtestKitchen%2CwikimediaEvents%7Cext.eventLogging.metricsPlatform%7Cext.quicksurveys.init%2Clib%7Cext.relatedArticles.readMore.bootstrap%7Cext.uls.interface%2Cpreferences%2Cwebfonts%7Cext.uls.rewrite.entrypoints%7Cext.urlShortener.toolbar%7Cext.wikimediaEvents.testKitchen%7Cjquery.client%2Cspinner%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.libs.pluralruleparser%7Cmediawiki.page.media%2Cready%7Cmediawiki.page.watch.ajax%7Cmediawiki.template.mustache%7Cmmv.bootstrap%2Ccodex%7Cmobile.codex.styles%7Cmobile.init%2Cstartup%7Cmw.cx.SiteMapper%7Cmw.externalguidance.init%7Cskins.minerva.scripts%7Cwikibase.databox.fromWikidata&skin=minerva&version=19u5i 818:13906 "Learn more about how we build our mobile site @ https://www.mediawiki.org/wiki/Special:MyLanguage/Extension:MobileFrontend"

Requests loaded after onLoad event

4 requests

Includes requests done after load event end.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript1.5 KB1
image2.1 KB1
font0 b0
favicon1.8 KB1
Total5.3 KB4

Requests loaded after onContentLoad

7 requests

Includes requests done after DOM content loaded.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript377.7 KB4
image2.1 KB1
font0 b0
favicon1.8 KB1
Total381.6 KB7

CPU

load.php[startup] is responsible for 72% of blocking time
711 ms of 986 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.

TBT925 ms
Max potential input delay244 ms
Total long tasks13
Total time1.812 s
Last task at4.313 s
Before first paint337 ms2 tasks
Before FCP337 ms2 tasks
Before LCP421 ms3 tasks
After load1.283 s8 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 frames13showing the 10 with the most blocking time
Blocking time1.268 sacross all long frames — what hurts INP and TBT
Forced style & layout46.9 msscripts reading layout mid-frame
Blocking before LCP261.7 msdelaying the largest paint — fix these first
Blocking after load997 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]4836.9 ms711.5 ms45.2 mstimer or animation callback
load.php[scripts:@wikimedia/codex]4419.8 ms270.4 ms1.7 mstimer or animation callback, script tag
Jannik_Sinner110.7 ms4.1 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 · 385.3 msat 2.231 s · after load
blocking 335.3 ms
  • Scripts & other work244.6 ms
  • Animation callbacks96.4 ms
  • Style & layout44.3 ms
  • Render0 ms
2 scripts ran during this frame
Ran for
241.8 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
96.4 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 · 294.7 msat 3.087 s · after load
blocking 193.5 ms
  • Scripts & other work63.6 ms
  • Animation callbacks198.2 ms
  • Style & layout32.9 ms
  • Render0 ms
5 scripts ran during this frame · forced style & layout 46.9 ms
Ran for
7.5 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 417489 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Ran for
7.2 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 417489 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Ran for
9.7 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
12.3 ms
Forced style and layout
1.7 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 417489 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Ran for
196.4 ms
Forced style and layout
45.2 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 · 244.6 msat 2.838 s · after load
blocking 185.4 ms
  • Scripts & other work241.3 ms
  • Animation callbacks3.2 ms
  • Style & layout0.1 ms
  • Render0 ms
1 script ran during this frame
Ran for
232.1 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 417489 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Long animation frame #4 · 484.6 msat 472.9 ms · before LCP
blocking 183.1 ms
  • Scripts & other work479.3 ms
  • Animation callbacks3.2 ms
  • Style & layout2.1 ms
  • Render0 ms
1 script ran during this frame
Ran for
10.7 ms
Queued before running
2.7 ms
How it started
script tag
Long animation frame #5 · 168.9 msat 2.653 s · after load
blocking 118.8 ms
  • Scripts & other work100.2 ms
  • Animation callbacks57.8 ms
  • Style & layout10.9 ms
  • Render0 ms
2 scripts ran during this frame
Ran for
100 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
56.2 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 #6 · 136.3 msat 4.313 s · after load
blocking 86.3 ms
  • Scripts & other work136.3 ms
  • Animation callbacks0 ms
  • Style & layout0 ms
  • Render0 ms
1 script ran during this frame
Ran for
136.4 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 #7 · 150 msat 3.393 s · after load
blocking 77.7 ms
  • Scripts & other work128.7 ms
  • Animation callbacks21.3 ms
  • Style & layout0 ms
  • Render0 ms
1 script ran during this frame
Ran for
106.5 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Position in source
character 417489 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Long animation frame #8 · 277.6 msat 1.021 s · before LCP
blocking 40.3 ms
  • Scripts & other work271.4 ms
  • Animation callbacks0 ms
  • Style & layout6.2 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 · 150.8 msat 1.325 s · before LCP
blocking 38.3 ms
  • Scripts & other work97.6 ms
  • Animation callbacks53.2 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 #10 · 55.5 msat 2.165 s · before load
blocking 5.5 ms
  • Scripts & other work55.5 ms
  • Animation callbacks0 ms
  • Style & layout0 ms
  • Render0 ms
1 script ran during this frame
Ran for
54.2 ms
Queued before running
14.5 ms
How it started
script tag

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]
711 ms · 7 frames · worst 240 ms
load.php[scripts:@wikimedia/codex]
270 ms · 6 frames · worst 178 ms
https://it.wikipedia.org/wiki/Jannik_Sinner
4 ms · 1 frame · worst 4 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.

TBT1.299 s
Blocking tasks17
TBT before LCP317.6 ms5 tasks

What kind of work blocked

mostly running javascript · 1.299 s total
Running JavaScript854.0 ms65.7%
Style & layout280.8 ms21.6%
Other browser work84.7 ms6.5%
Paint & composite43.0 ms3.3%
Parsing HTML & CSS28.7 ms2.2%
Garbage collection5.6 ms0.4%
Parsing & compiling JavaScript2.1 ms0.2%
Running JavaScript (66%): the scripts responsible are listed right below. See Slowest JS functions · Timers
Style & layout (22%): usually a large DOM, expensive CSS selectors or JavaScript forcing synchronous layout. See Forced reflows · Forced layout per script · Style invalidations (Rendering tab)

Top scripts blocking the main thread

3 of 3 scripts
load.php[startup]
649 ms · 7 tasks
Browser's own work (no script responsible)
396 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

3.219 s total
Running JavaScript1.525 s47.4%
Other browser work (scheduling)728 ms22.6%
Style & layout429 ms13.3%
Parsing HTML & CSS389 ms12.1%
Paint & composite111 ms3.4%
Parsing & compiling JavaScript24 ms0.7%
Garbage collection13 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 722 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] (19.9 ms)
load.php[startup]109.4 ms129.5 ms
setAttributeBrowser internal (not your code)95.4 ms95.4 ms
runScript
runs: load.php[scripts:@wikimedia/codex] (339.1 ms)
load.php[startup]90.0 ms602.8 ms
insertBeforeBrowser internal (not your code)67.3 ms67.3 ms
require
runs: load.php[scripts:@wikimedia/codex] (51.6 ms)
load.php[startup]46.4 ms112.1 ms
(anonymous)load.php[scripts:@wikimedia/codex]46.1 ms46.1 ms
querySelectorAllBrowser internal (not your code)44.5 ms44.5 ms
impl
runs: load.php[startup] (1.9 ms), load.php[scripts:@wikimedia/codex] (1.3 ms)
load.php[startup]40.0 ms45.1 ms
find
runs: querySelectorAll (39.3 ms), load.php[scripts:@wikimedia/codex] (14.6 ms), getElementsByTagName (2.7 ms), getElementsByClassName (2.5 ms)
load.php[scripts:@wikimedia/codex]27.1 ms86.7 ms
setTimeoutBrowser internal (not your code)24.2 ms24.2 ms
t
runs: load.php[scripts:@wikimedia/codex] (203.1 ms)
load.php[scripts:@wikimedia/codex]24.1 ms189.7 ms
(anonymous)
runs: after (16.9 ms), setAttribute (2.5 ms), createElement (1.2 ms)
load.php[scripts:@wikimedia/codex]21.8 ms42.4 ms
resources/lib/vue/vue.js
runs: load.php[scripts:@wikimedia/codex] (14.3 ms)
load.php[scripts:@wikimedia/codex]21.3 ms35.6 ms
updateTooltipOnElement
runs: load.php[scripts:@wikimedia/codex] (5.7 ms)
load.php[scripts:@wikimedia/codex]19.5 ms25.2 ms
doPropagation
runs: load.php[startup] (331.6 ms), load.php[scripts:@wikimedia/codex] (1.1 ms)
load.php[startup]16.9 ms349.7 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 set55
Times fired53
Fire time435.4 ms
Zero-delay timers50
Repeating timers0
Zero-delay slicing: load.php[scripts:@wikimedia/codex] split work into 48 back-to-back tasks costing 421 ms. Consider batching the work or moving it to requestIdleCallback or a worker.

Timer cost by script

2 scripts
load.php[scripts:@wikimedia/codex]
287 ms · set 54 times · fired 38 times
load.php[startup]
149 ms · set 1 time · fired 15 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]
45 ms · 2 reflows · worst 42 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

2 of 2 scripts
load.php[startup]
45 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 party1.421 s
Third party0 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.