Run 2 summary

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

Tested 2026-09-20 13:01:32 using Chrome 152.0.7977.64 (runtime settings)

SummaryWaterfallMetricsRenderingCoachPageXrayCPU

Summary

Google Web Vitals

405 msTTFB
880 msLargest Contentful Paint
0.052Cumulative Layout Shift

Loading

764 msFirst Paint
1.906 sFully Loaded

Page weight & requests

701.5 KBTotal transfer size
2.6 MBTotal content size
50Requests

Visual progress

733 msFirst Visual Change
942 msSpeed Index
1.033 sVisual Complete 85%
1.933 sVisual Complete 99%
1.933 sLast Visual Change
Screenshot
Run 2 · after page complete

Waterfall

First paintFCPLCPDOMContentLoadedDOM interactiveLoadRender-blockingRedirectError

Rendering

Run 2
0.000 s
0s1s2s
Download video

Filmstrip

12 frames

Use --filmstrip.showAll to show all filmstrips.

Frame at 0 ms
0 ms
0 %
Frame at 800 ms
800 ms
44 %
Frame at 900 ms
900 ms
80 %
Frame at 1.000 s
1.000 s
81 %
Frame at 1.100 s
1.100 s
88 %
Frame at 1.400 s
1.400 s
88 %
Frame at 1.500 s
1.500 s
86 %
Frame at 1.600 s
1.600 s
88 %
Frame at 1.700 s
1.700 s
88 %
Frame at 1.800 s
1.800 s
92 %
Frame at 1.900 s
1.900 s
94 %
Frame at 2.000 s
2.000 s
100 %

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

Visual instability

40.64 % of pixels ever changed · 0.03 % 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 shown27
Partial1
Dropped0
Effective FPS13.5
Longest gap748 msat 11 ms

Why was rendering delayed?

Rendering was not meaningfully delayed. First paint landed at 764 ms on a 405 ms first byte; the 2 render-blocking requests were done by 680 ms. The largest paint followed at 880 ms.

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 2 590 elements cost 57 ms before the page painted (7.5 % of the time to First Contentful Paint), and a single recalculation of 2 451 elements accounts for 48 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

Recalculations8
Elements2590
Total time57.009 ms
Largest recalculation2451 elements · 47.843 ms

Before largest contentful paint

Recalculations15
Elements5101
Total time92.476 ms
Largest recalculation2490 elements · 47.843 ms

The recalculation work before first paint is 7.5 % of the time to First Contentful Paint.

Render blocking requests

3 requests · 50.1 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 405 ms
639 ms
100.9 KB638 ms
site.stylesblocking
css · load.php styles batch · it.wikipedia.org
255 ms
2.2 KB255 ms
ext.cite.parsoid.styles + 13 more modulesblocking
css · load.php styles batch · it.wikipedia.org
252 ms
25.6 KB252 ms
startuppotentially blocking
javascript · load.php startup · it.wikipedia.org
281 ms
22.3 KB281 ms
0220 ms440 ms660 msFCP 764 msLCP 880 ms

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. 1 181 style recalculations and 8 714 layout invalidations fired after first paint, on a page the user was already looking at. The biggest driver is attribute title (170×). Start with the script under "Scripts causing invalidations" that keeps triggering it.

Style recalculations1 1981 181 after first paint
Layout invalidations10 2918 714 after first paint

Changes that keep invalidating

top 15
  • attribute: title170×
  • pseudo: has75×
  • attribute: class30×
  • attribute: hidden
  • class: mw-made-collapsible
  • attribute: style
  • pseudo: disabled
  • pseudo: enabled
  • class: mw-collapsed
  • attribute: id
  • attribute: disabled
  • attribute: role
  • attribute: href
  • pseudo: visited
  • class: vector-animations-ready

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 page22
An element entered layout2 825
An SVG element changed1
An element's size changed3
Unknown2
Scrollbar changed3

After the largest paint

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

ReasonStyle recalculationsLayout
A stylesheet rule changed552
Related style rule300
A node was inserted into the page217
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.75
Attribute8
An @keyframes rule changed4
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 element entered layout5 114
An element left layout516
List value change154
An SVG element changed59
An element's size changed13
A style change forced layout15
Unknown9

Before first paint: building the page

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

ReasonStyle recalculationsLayout
A stylesheet rule changed1
A node was inserted into the page16
An element entered layout1 565
An element left layout4
An SVG element changed1
An element's size changed2
A style change forced layout1
Unknown2
Scrollbar changed2

Scripts causing invalidations

top 3

Coach

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

Performance advice

88
8 warnings3 info
warn(0)Serve images in modern formats (AVIF, WebP)modernImageFormats

The page ships 106 images (out of 106) 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 20 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 133.2 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 424.3 kB and the uncompressed size is 1.7 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=vector-202222.3 KB67.3 KB
https://it.wikipedia.org/w/load.php...ia.org/w/load.php4.1 KB8.3 KB
https://it.wikipedia.org/w/load.php...ia.org/w/load.php18.2 KB62.3 KB
https://it.wikipedia.org/w/load.php...ia.org/w/load.php326.2 KB1.3 MB
https://it.wikipedia.org/w/load.php...ia.org/w/load.php26.2 KB124.5 KB
https://it.wikipedia.org/w/load.php...ia.org/w/load.php2.8 KB14.6 KB
https://it.wikipedia.org/w/load.php...ia.org/w/load.php1.5 KB994 B
https://en.wikipedia.org/w/index.php...a.org/w/index.php9.0 KB26.5 KB
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(50)Don't use private headers on static contentprivateAssets

The page has 6 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 22 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(90)Avoid doing redirectsassetsRedirects

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

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

Offenders
infoMake each CSS response smalloptimalCssSize

https://it.wikipedia.org/w/load.php?lang=it&modules=ext.cite.parsoid.styles%7Cext.cite.styles%7Cext.dismissableSiteNotice.styles%7Cext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediaBadges%7Cext.wikimediaBadges.ulsV2%7Cext.wikimediamessages.styles%7Cjquery.makeCollapsible.styles%7Cmediawiki.skinning.content.parsoid%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022 size is 26.3 kB (26256) and that is bigger than the limit of 25 kB. Try to keep each CSS response under 25 kB.

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

Offenders
URLTransferContent
https://it.wikipedia.org/w/load.php...ia.org/w/load.php25.6 KB205.8 KB
infoAdd decoding="async" to non-critical imagesdecodingAsync

The page has 6 images (out of 110) without a decoding hint. Add decoding="async" to non-critical images so the browser can decode them off the main thread.

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

Offenders
warn(95)Inline CSS for faster first renderinlineCss

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

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

warn(99)Avoid slowing down the critical rendering pathavoidRenderBlocking

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

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

Offenders

Best practice advice

75
1 warning4 info
infoGive every image a textual alternativeimageAltText

The page has 13 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 26 responses that sets both a max-age and expires header. There are 50 responses that sets a server header.

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

Offenders
warn(50)Set a sensible viewport meta tagviewport

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

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

infoDo not send too long headerslongHeaders

https://it.wikipedia...iki/Jannik_Sinner 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 1338 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.20The tool or CMS that generated the HTML, from the page generator meta tag.
Layout viewport1904 × 18067 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 elements6,256Very 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 depth22The deepest nesting on the page. Deep branches cost more style recalculation.
Iframes0No embedded documents on this page.
Script tags6Number 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 storage915.5 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 Index0.94 show quickly the page looked done
First Visual Change0.73 sfirst paint reaches the screen
Last Visual Change1.93 sscreen stops changing · 1.20 s after first
nothing painted yet
≥85%
First Visual Change0.73 s
1.03 sVisual Complete 85%
Visual Complete 95% · Visual Complete 99% · Last Visual Change1.93 s
Visual Readiness1.20 s· first to last change
00.5 s1.0 s1.5 s
Visual progress
Visual progress at 0 s0.0s
Visual progress at 0.9 s0.9s
Visual progress at 1 s1.0s
Visual progress at 1.4 s1.4s
Visual progress at 1.5 s1.5s
Visual progress at 1.7 s1.7s
Visual progress at 1.8 s1.8s
Visual progress at 2 s2.0s
FCP0.76s
LCP0.88s
VC851.03s
0.0s0.4s0.8s1.2s1.6s2.0s

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.

880 msLCP render time

Phase breakdown

  • TTFB405 ms
  • Resource load delay0 ms
  • Resource load duration0 ms
  • Element render delay475 ms

Element

Element type
<p>
Element id
mwEg
Size (w × h)
93939
Load time
0 ms
Style recalculation before LCP
15 recalculations touching 5101 elements (92.476 ms) — the largest touched 2490 elements (47.843 ms)

DOM path

body > div:eq(2) > div > div:eq(2) > main#content > div#bodyContent > div#mw-content-text > div:eq(0) > section#mwAQ > p#mwEg
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.

0.052cumulative layout shift score

One shift is 51% of your 0.052 CLS. div:eq(2) moved at 1.707 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.

  • 0.027
    51% of CLSshifted at 1.707 s
    <div class="mw-content-container">
    body > div:eq(2) > div > div:eq(2)
    <div class="vector-column-start">
    body > div:eq(2) > div > div:eq(1)
    <div class="mw-dismissable-notice">
    body > div:eq(2) > div > div:eq(0) > div#siteNotice > div:eq(1)
    <a href="/w/index.php?title=Jannik_Sinner&amp;action=edit&amp;section=1" title="Edit section's source code: Biografia">
    body > div:eq(2) > div > div:eq(2) > main#content > div#bodyContent > div#mw-content-text > div:eq(0) > section#mwjQ > div > span > a:eq(1)
    <a href="/w/index.php?title=Jannik_Sinner&amp;veaction=edit&amp;section=1" title="Modifica la sezione Biografia" class="mw-editsection-visualeditor">
    body > div:eq(2) > div > div:eq(2) > main#content > div#bodyContent > div#mw-content-text > div:eq(0) > section#mwjQ > div > span > a:eq(0)
  • 0.022
    42% of CLSshifted at 1.381 s
    <div class="mw-content-container">
    body > div:eq(2) > div > div:eq(2)
    <div class="vector-column-start">
    body > div:eq(2) > div > div:eq(1)
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
mwStartup855 ms
mwCentralNoticeBanner1.683 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 ms2589154099

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
Documents51
Frames28
JS event listeners703
Layout objects9516
Media key sessions0
Media keys0
Nodes13777
Resources78
Context lifecycle state observers78
V8 per context datas3
Worker global scopes0
Uacss resources0
Rtc peer connections0
Resource fetchers51
Ad subframes0
Detached script states2
Array buffer contents4
Layout count16
Recalc style count21
Layout duration95
Recalc style duration173
Dev tools command duration121
Script duration218
V8 compile duration4
Task duration894
Task other duration283
Thread time1
Process time2
JS heap used size10457232
JS heap total size14000128
First meaningful paint877
Visual Elements3
LargestImage250px-Jannik_Sinner_2025_US_Open.jpg?utm_source=it.wikipedia.org&utm_campaign=parser&utm_content=thumbnail
Display time1.733 s
Position (x, y)1124, 353
Size (w × h)225 × 300
HTML snippet
<img resource="https://it.wikipedia.org/wiki/File:Jannik_Sinner_2025_US_Open.jpg" src="//thumb.wikimedia.org/wikipedia/commons/thumb/6/64/Jannik_Sinner_2025_US_Open.jpg/250px-Jannik_Sinner_2025_US_Open.jpg?utm_source=it.wikipedia.org&amp;utm_campaign=parser&amp;utm_content=thumbnail" decoding="async" loading="lazy" srcset="//thumb.wikimedia.org/wikipedia/commons/thumb/6/64/Jannik_Sinner_2025_US_Open.jpg/500px-Jannik_Sinner_2025_US_Open.jpg?utm_source=it.wikipedia.org&amp;utm_campaign=parser&amp;utm_content=thumbnail 2x" data-file-width="1200" data-file-height="1600" data-file-type="bitmap" height="300" width="225" class="mw-file-element">
Heading
Display time1.733 s
Position (x, y)478, 222
Size (w × h)831 × 40
HTML snippet
<h1 id="firstHeading" class="firstHeading mw-first-heading"></h1>
LargestContentfulPaint
Display time1.733 s
Position (x, y)478, 361
Size (w × h)948 × 182
HTML snippet
<p id="mwEg"></p>

PageXray

How the page is built.

HTTP versionHTTP/2.0
Total requests50
Total domains6
Transfer size701.5 KB
Content size2.6 MB
Missing compression0
Cookies250 third-party

Main document

status 200 · 0 redirects

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

HeaderValue
accept-ch
accept-rangesbytes
age5199
cache-controlprivate, s-maxage=0, max-age=0, must-revalidate, no-transform
content-encodinggzip
content-languageit
content-length97036
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 11:34:56 GMT
last-modifiedSun, 20 Sep 2026 11:12:01 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-z5jtr
server-timingcache;desc="hit-front", host;desc="cp3070",co_id;desc="2589154099"
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-id90f9609f-d64c-4e28-8f37-20ebeacedf99

Response codes

200
4998.0%
302
12.0%

Requests and sizes per content type

6 types

Transfer size701.5 KB

  • javascript59.1%
  • image17.4%
  • html14.4%
  • svg4.5%
  • css4.4%
  • favicon0.26%

Content size2.6 MB

  • javascript61.9%
  • html24.9%
  • css8.2%
  • image3.6%
  • svg1.3%
  • favicon0.10%

Requests49

  • svg38.8%
  • image30.6%
  • javascript20.4%
  • css6.1%
  • html2.0%
  • favicon2.0%
ContentHeader SizeTransfer SizeContent SizeRequests
html0 b100.9 KB653.7 KB1
css0 b30.7 KB214.7 KB3
javascript0 b414.3 KB1.6 MB10
image0 b121.9 KB93.9 KB15
favicon0 b1.8 KB2.7 KB1
svg0 b31.8 KB35.3 KB19
Total0 b701.5 KB2.6 MB49

Data per domain

6 domains
DomainTotal download timeTransfer SizeContent SizeRequests
it.wikipedia.org5.351 s571.4 KB2.4 MB31
thumb.wikimedia.org2.009 s61.5 KB41.7 KB10
upload.wikimedia.org1.865 s52.6 KB53.9 KB5
en.wikipedia.org390 ms11.9 KB32.2 KB2
auth.wikimedia.org186 ms1.5 KB254 B1
meta.wikimedia.org101 ms2.6 KB5.2 KB1

Expires & last-modified statistics

typeminmedianmax
Expires0 seconds4 weeks1 year
Last modified23 minutes7 weeks13 years

Requests loaded after onLoad event

23 requests

Includes requests done after load event end.

ContentTransfer SizeRequests
html0 b0
css2.9 KB1
javascript43.6 KB6
image40.0 KB3
font0 b0
favicon1.8 KB1
svg17.8 KB11
Total106.1 KB23

Requests loaded after onContentLoad

23 requests

Includes requests done after DOM content loaded.

ContentTransfer SizeRequests
html0 b0
css2.9 KB1
javascript43.6 KB6
image40.0 KB3
font0 b0
favicon1.8 KB1
svg17.8 KB11
Total106.1 KB23

CPU

Long tasks

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

✓ No long tasks observed during this run.

Long Animation Frames

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

Long animation frames6every frame ≥ 50 ms
Blocking time110.4 msacross all long frames — what hurts INP and TBT
Forced style & layout15.3 msscripts reading layout mid-frame
Blocking before LCP77.1 msdelaying the largest paint — fix these first
Blocking after load33.3 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]4106.4 ms29.7 ms15.3 msscript tag, timer or animation callback
load.php[scripts:@wikimedia/codex]134.1 ms9.1 mstimer or animation callback

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

Long animation frame #1 · 105.4 msat 709.2 ms · before LCP
blocking 50.9 ms
  • Scripts & other work15.4 ms
  • Animation callbacks89.9 ms
  • Style & layout0.1 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 #2 · 99.1 msat 829.7 ms · before LCP
blocking 26.2 ms
  • Scripts & other work33.3 ms
  • Animation callbacks65.8 ms
  • Style & layout0 ms
  • Render0 ms
1 script ran during this frame
Ran for
7.1 ms
How it started
script tag
Long animation frame #3 · 94.6 msat 1.413 s · after load
blocking 19.4 ms
  • Scripts & other work59.4 ms
  • Animation callbacks24.9 ms
  • Style & layout10.3 ms
  • Render0 ms
3 scripts ran during this frame · forced style & layout 15.3 ms
Ran for
34.1 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)
Ran for
13.3 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
24.9 ms
Forced style and layout
15.3 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 #4 · 70 msat 1.334 s · after load
blocking 13.9 ms
  • Scripts & other work43.2 ms
  • Animation callbacks21.2 ms
  • Style & layout5.6 ms
  • Render0 ms
3 scripts ran during this frame
Ran for
37 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
8 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)
Ran for
8.8 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)

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

Blocking time per script (browser-reported)

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

Top scripts blocking the main thread

2 of 2 scripts
load.php[startup]
30 ms · 6 frames · worst 10 ms
load.php[scripts:@wikimedia/codex]
9 ms · 1 frame · worst 9 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.

TBT80.9 ms
Blocking tasks2
TBT before LCP80.9 ms2 tasks

What kind of work blocked

mostly style & layout · 81 ms total
Style & layout65.9 ms81.5%
Other browser work7.3 ms9.0%
Paint & composite6.7 ms8.3%
Running JavaScript0.7 ms0.9%
Parsing HTML & CSS0.3 ms0.4%
Style & layout (81%): 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

1 of 1 script
Browser's own work (no script responsible)
81 ms · 2 tasks

Where the time went

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

Categories

815 ms total
Style & layout275 ms33.7%
Running JavaScript248 ms30.4%
Other browser work (scheduling)144 ms17.7%
Parsing HTML & CSS74 ms9.1%
Paint & composite59 ms7.2%
Garbage collection10 ms1.2%
Parsing & compiling JavaScript5 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 143 ms of it is this per-task bookkeeping (RunTask self time in the trace).

CPU time per script

Scripts by main-thread time

2 of 2 scripts

Slowest JS functions

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

Functions by self time

15 of 33 functions
FunctionWhereSelf timeTotal time
getPropertyValueBrowser internal (not your code)15.9 ms15.9 ms
setAttributeBrowser internal (not your code)15.7 ms15.7 ms
flushWrites
runs: load.php[startup] (1.8 ms)
load.php[startup]15.5 ms17.4 ms
runScript
runs: load.php[scripts:@wikimedia/codex] (45.8 ms), load.php[scripts:ext.cite.referencePreviews] (4.7 ms)
load.php[startup]10.8 ms91.0 ms
insertBeforeBrowser internal (not your code)10.6 ms10.6 ms
setTimeoutBrowser internal (not your code)10.2 ms10.2 ms
querySelectorAllBrowser internal (not your code)8.6 ms8.6 ms
appendChildBrowser internal (not your code)6.4 ms6.6 ms
require
runs: load.php[scripts:@wikimedia/codex] (7.0 ms)
load.php[startup]6.1 ms17.3 ms
implload.php[startup]4.9 ms7.2 ms
buildFragmentload.php[scripts:@wikimedia/codex]4.0 ms4.3 ms
resources/lib/vue/vue.js
runs: load.php[scripts:@wikimedia/codex] (1.9 ms)
load.php[scripts:@wikimedia/codex]3.9 ms5.8 ms
find
runs: querySelectorAll (6.5 ms), load.php[scripts:@wikimedia/codex] (1.7 ms)
load.php[scripts:@wikimedia/codex]3.8 ms13.2 ms
requestIdleCallbackBrowser internal (not your code)3.5 ms3.5 ms
doPropagation
runs: load.php[startup] (48.7 ms)
load.php[startup]3.4 ms53.6 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 set69
Times fired66
Fire time85.2 ms
Zero-delay timers63
Repeating timers0
Zero-delay slicing: load.php[scripts:@wikimedia/codex] split work into 61 back-to-back tasks costing 83 ms. Consider batching the work or moving it to requestIdleCallback or a worker.

Timer cost by script

3 scripts
load.php[startup]
51 ms · set 1 time · fired 19 times
load.php[scripts:@wikimedia/codex]
32 ms · set 68 times · fired 46 times

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

1 reflow ≥ 2 ms across 1 script
load.php[startup]
15 ms · 1 reflow · worst 15 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]
15 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 party246 ms
Third party0 ms
Domains1

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