Run 1 summary

LoginPage

Tested 2026-07-27 23:06:52 using Chrome 150.0.7871.186 (script).(runtime settings)

Test as a logged in user

Login the user with an empty browser cache, then visit Obama and Facebook

SummaryWaterfallMetricsRenderingCoachPageXrayCPU

Summary

Google Web Vitals

1.585 sTTFB
2.096 sLargest Contentful Paint
0.000Cumulative Layout Shift

Loading

1.996 sFirst Paint
7.737 sFully Loaded

Page weight & requests

410.3 KBTotal transfer size
1.7 MBTotal content size
18Requests

Visual progress

2.000 sFirst Visual Change
2.012 sSpeed Index
2.000 sVisual Complete 85%
2.466 sVisual Complete 99%
2.466 sLast Visual Change
Screenshot
Run 1 · after page complete

Waterfall

First paintFCPLCPDOMContentLoadedDOM interactiveLoadRender-blockingRedirectError

Rendering

Run 1
0.000 s
0s1s2s
Download video

Filmstrip

6 frames

Use --filmstrip.showAll to show all filmstrips.

Frame at 0 ms
0 ms
0 %
Frame at 2.000 s
2.000 s
95 %
Frame at 2.100 s
2.100 s
96 %
Frame at 2.200 s
2.200 s
98 %
Frame at 2.400 s
2.400 s
98 %
Frame at 2.500 s
2.500 s
100 %

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

Visual instability

5.05 % 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 shown44
Partial0
Dropped1
Effective FPS3.1
Longest gap615 msat 13.574 s

Why was rendering delayed?

The server dominated the wait. The first byte took 1.585 s (79 % of the time to First Contentful Paint). Nothing can render before it arrives, and Google Web Vitals considers a TTFB over 800 ms in need of improvement. See the request timing on the Waterfall tab. First paint landed at 1.996 s; the 1 render-blocking request was done by 1.902 s.

Style recalculation

measured by Chrome during this run

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

Style recalculation is not holding up your paint. 16 ms of restyling before the page painted, 0.8 % of the time to First Contentful Paint. Nothing here needs attention.

Before first contentful paint

Recalculations12
Elements607
Total time16.059 ms
Largest recalculation292 elements · 11.815 ms

Before largest contentful paint

Recalculations21
Elements713
Total time17.98 ms
Largest recalculation292 elements · 11.815 ms

The recalculation work before first paint is 0.8 % of the time to First Contentful Paint.

Render blocking requests

2 requests · 54.2 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
en.wikipedia.org · TTFB 1.585 s
488 ms
1.7 KB487 ms
ext.uls.interlanguage + 10 more modulesblocking
css · load.php styles batch · en.wikipedia.org
301 ms
33.4 KB301 ms
startuppotentially blocking
javascript · load.php startup · en.wikipedia.org
324 ms
20.8 KB324 ms
LCP resource
glyph-people-large.png — downloaded by 2.017 s, rendered at 2.096 s
101 ms
2.7 KB101 ms
0524 ms1.048 sFCP 1.996 sFCP · LCP 2.096 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. 130 style recalculations and 204 layout invalidations fired after first paint, on a page the user was already looking at. The biggest driver is attribute title (10×). Start with the script under "Scripts causing invalidations" that keeps triggering it.

Style recalculations156130 after first paint
Layout invalidations809204 after first paint

Changes that keep invalidating

top 9
  • attribute: title10×
  • attribute: class
  • attribute: href
  • pseudo: visited
  • pseudo: disabled
  • pseudo: enabled
  • attribute: disabled
  • class: vector-animations-ready
  • class: ve-not-available

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 page4
Control7
An animation updated stylesAnimate transform and opacity so the compositor can run it off the main thread.7
An element entered layout48
An SVG element changed42
An element's size changed2
Unknown2

After the largest paint

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

ReasonStyle recalculationsLayout
Related style rule72
A node was inserted into the page11
Control6
An animation updated stylesAnimate transform and opacity so the compositor can run it off the main thread.6
A stylesheet rule changed12
An @keyframes rule changed5
An element entered layout105
An element's size changed2
Unknown2
A style change forced layout1

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 page12
Control6
An animation updated stylesAnimate transform and opacity so the compositor can run it off the main thread.4
A stylesheet rule changed1
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 layout460
An SVG element changed132
An element's size changed3
Unknown3
An element left layout3
Scrollbar changed3
A style change forced layout1

Scripts causing invalidations

top 1

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

Coach

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

Performance advice

84
2 errors9 warnings3 info
infoAdd decoding="async" to non-critical imagesdecodingAsync

The page has 5 images (out of 5) 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(0)Avoid redirecting the main documentdocumentRedirect

The main document gets redirected 3 time(s). Remove those redirect and make the page faster!

You should never ever redirect the main document, because it will make the page load slower for the user. Well, you should redirect the user if the user tries to use HTTP and there's an HTTPS version of the page. The coach checks for that. :)

Offenders
warn(0)Total JavaScript size shouldn't be too bigjavascriptSize

The total JavaScript transfer size is 299.6 kB and the uncompressed size is 1.3 MB. This is totally crazy! There is really room for improvement here.

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

Offenders
URLTransferContent
https://en.wikipedia.org/w/load.php...ia.org/w/load.php20.8 KB62.3 KB
https://en.wikipedia.org/w/load.php...ia.org/w/load.php18.1 KB60.5 KB
https://en.wikipedia.org/w/load.php...ia.org/w/load.php253.7 KB1.1 MB
error(50)Have a fast first contentful paintfirstContentfulPaint

First contentful paint can be improved (1.996 s). It is in the Google Web Vitals needs improvement range, slower than 1.8 seconds.

The First Contentful Paint (FCP) metric measures the time from when the page starts loading to when any part of the page content is rendered on the screen. For this metric, "content" refers to text, images (including background images), <svg> elements, or non-white <canvas> elements.

warn(60)Don't scale images in the browseravoidScalingImages

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

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

Offenders
warn(70)Avoid extra requests by setting cache headerscacheHeaders

The page has 3 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 NaN undefined 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(80)Avoid doing redirectsassetsRedirects

The page has 2 redirects. 1 of the redirects are from the base domain, please fix them! 1 request are from other domains, it could be 3rd-party assets doing unnecessary redirects. :(

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

Offenders
warn(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
error(90)Avoid Frontend single point of failuresspof

The page has 1 request inside of the head that can cause a SPOF (single point of failure). Load them asynchronously or move them outside of the document head.

A page can be stopped from loading in the browser if a single JavaScript, CSS, and in some cases a font, couldn't be fetched or is loading really slowly (the white screen of death). That is a scenario you really want to avoid. Never load 3rd-party components synchronously inside of the head tag.

Offenders
warn(90)Always compress text contentcompressAssets

The page has 1 request that are served uncompressed. You could save a lot of bytes by sending them compressed instead.

In the early days of the Internet there were browsers that didn't support compressing (gzipping) text content. They do now. Make sure you compress HTML, JSON, JavaScript, CSS and SVG. It will save bytes for the user; making the page load faster and use less bandwith.

Offenders
URLTransferContent
https://auth.wikimedia.org/enwiki/wiki/Special:UserLogin...Special:UserLogin14.1 KB39.0 KB
infoMake each CSS response smalloptimalCssSize

https://en.wikipedia.org/w/load.php?lang=en&modules=ext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.webauthn.passwordlessLogin.styles%7Cmediawiki.codex.messagebox.styles%7Cmediawiki.htmlform.codex.styles%7Cmediawiki.htmlform.styles%7Cmediawiki.special.userlogin.common.styles%7Cmediawiki.special.userlogin.login.styles%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles&only=styles&skin=vector-2022 size is 34.2 kB (34209) and that is bigger than the limit of 25 kB. Try to keep each CSS response under 25 kB.

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

Offenders
URLTransferContent
https://en.wikipedia.org/w/load.php...ia.org/w/load.php33.4 KB303.7 KB
infoLong cache headers is goodcacheHeadersLong

The page has 6 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(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 1 blocking requests and 0 in body parser blocking (0 JavaScript and 1 CSS). There are 1 potentially render blocking requests. You need to verify if it is render blocking: https://en.wikipedia.org/w/load.php?lang=en&modules=startup&only=scripts&raw=1&safemode=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.

Best practice advice

67
2 warnings4 info
infoMeta descriptionmetaDescription

The page is missing a meta description.

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

warn(0)Avoid too many third party requeststhirdParty

The page do 50% requests to third party domains (9 requests and 340 kB). First party is 9 requests and 80.2 kB. The page transfer more bytes from third party domains (340 kB) then first party (80.2 kB). The regex .*wikimedia.* was used to calculate first/third party requests.

Do not load most of your content from third party URLs.

infoHave a good URL formaturl

The page is using more than two request parameters. You should really rethink and try to minimize the number of parameters. The URL is 158 characters long. Try to make it less than 100 characters.

A clean URL is good for the user and for SEO. Make them human readable, avoid too long URLs, spaces in the URL, too many request parameters, and never ever have the session id in your URL.

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

infoAvoid unnecessary headersunnecessaryHeaders

There are 14 responses that sets both a max-age and expires header. There are 18 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://auth.wikimed...Special:UserLogin has a header set-cookie that is 616 characters long. https://en.wikipedia...ia.org/w/load.php has a header sourcemap that is 1099 characters long.

Do not send response headers that are too long.

Offenders

Privacy advice

75
5 warnings2 info
warn(0)Use a strict Content-Security-Policy header to mitigate cross-site scripting (XSS) attacks.contentSecurityPolicyHeader

Set a Content-Security-Policy header to mitigate cross-site scripting attacks. You can start with a Content-Security-Policy-Report-Only header, which only reports violations rather than blocking them.

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

Offenders
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(20)Avoid third party cookies that is used to track the user.thirdPartyCookies

The page sets 8 third party cookies.

Third party cookies are used to track the user. They are automatically blocked in Safari and Firefox.

Offenders
  • .wikipedia.org
  • .wikipedia.org
  • .wikipedia.org
  • .wikipedia.org
  • .wikipedia.org
  • .wikipedia.org
  • .wikipedia.org
  • .wikipedia.org

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.

TitleLog in - WikipediaThe document title, shown in the browser tab and used by search results.
GeneratorMediaWiki 1.47.0-wmf.12The tool or CMS that generated the HTML, from the page generator meta tag.
Layout viewport1919 × 992 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 elements449Total HTML elements. Fewer means less for the browser to style, lay out and paint.
Avg DOM depth11How deeply elements are nested on average.
Max DOM depth20The deepest nesting on the page. Deep branches cost more style recalculation.
Iframes0No embedded documents on this page.
Script tags4Number 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 storage65 BData 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.

Technologies used to build the page

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

Detected technologies

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

Visual Metrics

Visual milestones

all times from navigation start
Speed Index2.01 show quickly the page looked done
First Visual Change2.00 sfirst paint reaches the screen
Last Visual Change2.47 sscreen stops changing · 0.47 s after first
nothing painted yet
≥95% rendered
First Visual Change · Visual Complete 85% · Visual Complete 95%2.00 s
Visual Complete 99% · Last Visual Change2.47 s
Visual Readiness0.47 s· first to last change
00.5 s1.0 s1.5 s2.0 s
Visual progress
Visual progress at 0 s0.0s
Visual progress at 2 s2.0s
Visual progress at 2.1 s2.1s
Visual progress at 2.2 s2.2s
Visual progress at 2.4 s2.4s
Visual progress at 2.5 s2.5s
FCP2.00s
LCP2.10s
VC852.00s
0.0s0.5s1.0s1.5s2.0s2.5s

Google Web Vitals

1.585 sTTFB
Needs improvement
1.996 sFCP
Needs improvement

Largest Contentful Paint

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

2.096 sLCP render time

Phase breakdown

  • TTFB1.585 s
  • Resource load delay0 ms
  • Resource load duration0 ms
  • Element render delay511 ms

Element

Element type
<div>
Element id
mw-createaccount-cta
Size (w × h)
20114
URL
https://en.wikipedia...-people-large.png
Load time
2.023 s
Style recalculation before LCP
21 recalculations touching 713 elements (17.98 ms) — the largest touched 292 elements (11.815 ms)

DOM path

body > div:eq(2) > div > div:eq(2) > main#content > div#bodyContent > div#mw-content-text > div:eq(1) > div#userloginForm > form > div:eq(7) > div > div#mw-createaccount-cta
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
TTFB1.585 s
User Timing marks
mwStartup1.953 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 mspass
host0 mscp3070
co_id0 ms2457372389

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
Documents25
Frames17
JS event listeners97
Layout objects625
Media key sessions0
Media keys0
Nodes1757
Resources15
Context lifecycle state observers44
V8 per context datas3
Worker global scopes0
Uacss resources0
Rtc peer connections0
Resource fetchers25
Ad subframes0
Detached script states2
Array buffer contents3
Layout count5
Recalc style count28
Layout duration13
Recalc style duration22
Dev tools command duration75
Script duration105
V8 compile duration2
Task duration326
Task other duration108
Thread time1
Process time2
JS heap used size5977164
JS heap total size8388608
First meaningful paint1994
Visual Elements3
LargestImagewikipedia-wordmark-en-25.svg
Display time2.000 s
Position (x, y)314, 14
Size (w × h)140 × 22
HTML snippet
<img class="mw-logo-wordmark" alt="Wikipedia" src="/static/images/mobile/copyright/wikipedia-wordmark-en-25.svg" style="width: 8.75em; height: 1.375em;">
Heading
Display time2.000 s
Position (x, y)350, 66
Size (w × h)948 × 40
HTML snippet
<h1 id="firstHeading" class="firstHeading mw-first-heading"></h1>
LargestContentfulPaint
Display time2.000 s
Position (x, y)434, 456
Size (w × h)280 × 163
HTML snippet
<div id="mw-createaccount-cta"></div>

PageXray

How the page is built.

HTTP versionHTTP/2.0
Total requests18
Total domains2
Transfer size410.3 KB
Content size1.7 MB
Missing compression1
Cookies88 third-party

Main document

status 200 · 3 redirects

https://auth.wikimedia.org/enwiki/wiki/Special:UserLogin?useformat=desktop&usesul3=1&returnto=Main+Page&centralauthLoginToken=fe0396f0b9c62e2a1e4e8eb36f549670

HeaderValue
age0
cache-controlprivate, s-maxage=0, max-age=0, must-revalidate, no-transform
content-length0
content-typetext/html; charset=UTF-8
dateMon, 27 Jul 2026 23:06:53 GMT
expiresThu, 01 Jan 1970 00:00:00 GMT
locationhttps://auth.wikimedia.org/metawiki/wiki/Special:CentralAutoLogin/checkLoggedIn?useformat=desktop&type=redirect&returnUrlToken=e4e4d157644ae07bae904103a05e2e65&wikiid=enwiki&usesul3=1&useformat=desktop
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" }] }
servermw-web.eqiad.main-5fc9744499-fpdpb
server-timingcache;desc="pass", host;desc="cp3070",co_id;desc="1963838229"
strict-transport-securitymax-age=106384710; includeSubDomains; preload
varyAccept-Encoding,X-Forwarded-Proto,Cookie,Authorization,User-Agent
x-analytics
x-cachecp3070 miss, cp3070 pass
x-cache-statuspass
x-client-ip138.201.135.103
x-content-type-optionsnosniff
x-request-id3f496791-11e4-41d0-a4e6-536fff73f241

Response codes

200
1477.8%
202
15.6%
302
316.7%

Requests and sizes per content type

7 types

Transfer size410.3 KB

  • javascript71.3%
  • svg15.8%
  • css8.1%
  • html3.4%
  • image0.66%
  • favicon0.44%
  • plain0.22%

Content size1.7 MB

  • javascript71.9%
  • css17.0%
  • svg8.7%
  • html2.2%
  • favicon0.15%
  • image0.09%

Requests15

  • svg46.7%
  • javascript20.0%
  • html6.7%
  • css6.7%
  • image6.7%
  • favicon6.7%
  • plain6.7%
ContentHeader SizeTransfer SizeContent SizeRequests
html0 b14.1 KB39.0 KB1
css0 b33.4 KB303.7 KB1
javascript0 b292.6 KB1.3 MB3
image0 b2.7 KB1.6 KB1
favicon0 b1.8 KB2.7 KB1
svg0 b64.8 KB155.6 KB7
plain0 b905 B0 b1
Total0 b410.3 KB1.7 MB15

Data per domain

2 domains
DomainTotal download timeTransfer SizeContent SizeRequests
en.wikipedia.org2.996 s332.0 KB1.6 MB9
auth.wikimedia.org2.163 s78.3 KB196.8 KB9

Expires & last-modified statistics

typeminmedianmax
Expires0 seconds4 weeks1 year
Last modified4 days3 weeks3 weeks

Requests loaded after onLoad event

2 requests

Includes requests done after load event end.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript0 b0
image0 b0
font0 b0
favicon1.8 KB1
plain905 B1
Total2.7 KB2

Requests loaded after onContentLoad

4 requests

Includes requests done after DOM content loaded.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript271.8 KB2
image0 b0
font0 b0
favicon1.8 KB1
plain905 B1
Total274.5 KB4

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 frames1every frame ≥ 50 ms
Blocking time0 msacross all long frames — what hurts INP and TBT

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

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

292 ms total
Running JavaScript130 ms44.5%
Other browser work (scheduling)70 ms24.0%
Style & layout41 ms14.0%
Parsing HTML & CSS21 ms7.2%
Paint & composite20 ms6.8%
Garbage collection6 ms2.1%
Parsing & compiling JavaScript4 ms1.4%
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 69 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 20 functions
FunctionWhereSelf timeTotal time
runScript
runs: load.php[scripts:ext.centralNotice.geoIP] (27.2 ms), load.php[scripts:ext.visualEditor.core.utils.parsing] (1.8 ms)
load.php[startup]9.0 ms49.6 ms
setTimeoutBrowser internal (not your code)6.0 ms6.0 ms
appendChildBrowser internal (not your code)5.7 ms5.7 ms
require
runs: load.php[scripts:ext.centralNotice.geoIP] (1.1 ms)
load.php[startup]4.9 ms11.8 ms
implload.php[startup]4.6 ms6.0 ms
(anonymous)load.php[scripts:ext.centralNotice.geoIP]3.4 ms3.7 ms
requestAnimationFrameBrowser internal (not your code)2.6 ms2.6 ms
requestIdleCallbackBrowser internal (not your code)2.6 ms2.6 ms
(anonymous)
runs: load.php[scripts:ext.centralNotice.geoIP] (13.4 ms)
load.php[scripts:ext.centralNotice.geoIP]2.3 ms15.8 ms
(anonymous)
runs: load.php[scripts:ext.centralNotice.geoIP] (8.4 ms)
load.php[scripts:ext.centralNotice.geoIP]2.1 ms13.4 ms
each
runs: load.php[scripts:ext.centralNotice.geoIP] (3.8 ms)
load.php[scripts:ext.centralNotice.geoIP]1.8 ms8.6 ms
(anonymous)load.php[scripts:ext.centralNotice.geoIP]1.6 ms1.6 ms
(anonymous)load.php[scripts:ext.centralNotice.geoIP]1.6 ms1.6 ms
doPropagation
runs: load.php[startup] (42.6 ms)
load.php[startup]1.5 ms44.7 ms
updateTooltipOnElementload.php[scripts:ext.centralNotice.geoIP]1.5 ms2.4 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 set41
Times fired39
Fire time28.7 ms
Zero-delay timers36
Repeating timers0
Zero-delay slicing: load.php[scripts:ext.centralNotice.geoIP] split work into 34 back-to-back tasks costing 26 ms. Consider batching the work or moving it to requestIdleCallback or a worker.

Timer cost by script

2 scripts
load.php[startup]
17 ms · set 0 times · fired 13 times
load.php[scripts:ext.centralNotice.geoIP]
12 ms · set 41 times · fired 26 times

First vs third party CPU time

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

First party110 ms
Third party2 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.

Each chip below is a CSS property the page tried to animate that Chrome couldn't hand to the compositor. Swap it for a transform or opacity equivalent where you can.

Properties to fix

5 properties · 5 animations
  • border-bottom-color
  • border-left-color
  • box-shadow
  • border-right-color
  • border-top-color

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