Page summary

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

Tested 2026-05-26 02:45:36 using Chrome 148.0.7778.96 (runtime settings)

SummaryWaterfall MetricsVideoFilmstrip CoachPageXrayCPU
| Summary | | Download Video | Download Timeline Log | Download HAR | Download Console Logs | 

Summary

LCP1.120 s
CLS0.687
Coach81
Loading & responsiveness (median)
TTFB
395 ms
First Paint
768 ms
Fully Loaded
2.963 s
Total Blocking Time
637 ms
Max Potential FID
214 ms
Page weight & requests
Total transfer size
1.0 MB
Requests
42
CPU
CPU long tasks
12
CPU longest task duration
261 ms
CPU last long task at
3.559 s
Visual progress
First Visual Change
767 ms
Speed Index
1.603 s
Visual Complete 85%
2.667 s
Visual Complete 99%
2.767 s
Last Visual Change
2.767 s
Screenshot of run 1

Timings Summary

Metricminmedianmeanmax
Visual Metrics
FirstVisualChange767 ms767 ms767 ms767 ms
LastVisualChange2.733 s2.767 s2.778 s2.833 s
SpeedIndex1.593 s1.603 s1.611 s1.637 s
LargestImage2.667 s2.700 s2.722 s2.800 s
Heading2.667 s2.700 s2.722 s2.800 s
LastMeaningfulPaint2.667 s2.700 s2.722 s2.800 s
VisualReadiness1.966 s2.000 s2.011 s2.066 s
VisualComplete852.633 s2.667 s2.678 s2.733 s
VisualComplete952.667 s2.700 s2.722 s2.800 s
VisualComplete992.733 s2.767 s2.778 s2.833 s
Google Web Vitals
Time To First Byte (TTFB)395 ms395 ms395 ms395 ms
Largest Contentful Paint (LCP)1.100 s1.120 s1.133 s1.180 s
Cumulative Layout Shift (CLS)0.37620.6870.58340.687
More metrics
firstPaint768 ms768 ms769 ms772 ms
loadEventEnd2.730 s2.735 s2.770 s2.845 s
User Timing
mwStartup769 ms771 ms771 ms773 ms
mwCentralNoticeBanner2.556 s2.558 s2.589 s2.652 s
CPU
Total Blocking Time620 ms637 ms637 ms655 ms
Max Potential FID190 ms214 ms222 ms261 ms
CPU long tasks 11121213
CPU last long task happens at3.544 s3.559 s3.598 s3.692 s
Waterfall | Download HAR | 

Waterfall

Run 1 SpeedIndex median

First paintFCPLCPDOMContentLoadedDOM interactiveLoadRender-blockingRedirectError

Video

Run 1 · median
Download video

Filmstrip

22 frames

Use --filmstrip.showAll to show all filmstrips.

0 s
0.7 sCPU Long Task duration 90 ms
0.8 sFirst Visual Change 767 msCPU Long Task duration 59 msFirst Contentful Paint 768 msmwStartup 771 ms
1 s
1.1 sCPU Long Task duration 90 ms
1.2 sLCP <P> 1.120 sCPU Long Task duration 59 ms
1.3 sCPU Long Task duration 55 ms
1.4 s
1.5 sCPU Long Task duration 196 ms
1.6 s
1.7 sCPU Long Task duration 261 ms
1.8 s
1.9 s
2 sCPU Long Task duration 61 ms
2.1 sCPU Long Task duration 72 ms
2.2 sDOM Content Loaded Time 2.153 s
2.3 sCPU Long Task duration 165 ms
2.4 s
2.5 s
2.6 smwCentralNoticeBanner 2.556 sLayout Shift 0.31079 2.594 s
2.7 sVisual Complete 85% 2.633 sLayout Shift 0.37617 2.659 sVisual Complete 95% 2.700 sLargest Image 2.700 sHeading 2.700 s
2.8 sPage Load Time 2.729 sLast Visual Change 2.733 sVisual Complete 99% 2.733 s
Performance advice | Best practice advice | Privacy advice | Page info | Technologies | 

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

81
11 warnings2 info
warn(0)Avoid CPU Long TaskslongTasks

The page has 11 CPU long tasks with the total of 1.227 s. The total blocking time is 637 ms and 1 long task before first contentful paint with total time of 90 ms. However the CPU Long Task is depending on the computer/phones actual CPU speed, so you should measure this on the same type of the device that your user is using. Use Geckoprofiler for Firefox or Chromes tracelog to debug your long tasks.

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

Offenders
  • unknown
  • self
  • unknown
  • unknown
  • unknown
  • self
  • self
  • self
  • self
  • self
  • self
warn(0)Serve images in modern formats (AVIF, WebP)modernImageFormats

The page ships 19 images (out of 19) 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 21 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 738.3 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(15)Lazy-load below-the-fold imageslazyLoadingImages

The page has 17 below-the-fold images without loading="lazy". Add loading="lazy" so the browser defers downloading and decoding them until the user scrolls them into view.

Adding loading="lazy" to an <img> tells the browser not to download or decode it until it is close to the viewport. For images that the user may never see (deep in the page, behind a tab, in a footer carousel), this saves bandwidth and main-thread time during initial render. The LCP image and any image in the initial viewport should NOT be lazy-loaded — that delays the first paint. https://developer.mozilla.org/en-US/docs/Web/HTML/Element/img#loading

Offenders
warn(50)Don't scale images in the browseravoidScalingImages

The page has 5 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(50)Total image size shouldn't be too bigimageSize

The page total image size is 725.4 kB. It's really big. Is the page using the right format for the images? Can they be lazy loaded? Are they compressed as good as they can be? Make them smaller by using https://imageoptim.com/.

Avoid having too many large images on the page. The images will not affect the first paint of the page, but it will eat bandwidth for the user.

warn(50)Total JavaScript size shouldn't be too bigjavascriptSize

The total JavaScript transfer size is 244.7 kB and the uncompressed size is 941.7 kB. This is quite large.

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

Offenders
URLTransferContent
https://en.wikipedia.org/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=minerva22.0 KB66.1 KB
https://en.wikipedia.org/w/load.php?lang=en&modules=ext.gadget.switcher&skin=minerva&version=sfqnf1.6 KB1.3 KB
https://en.wikipedia.org/w/load.php...ia.org/w/load.php9.0 KB25.5 KB
https://en.wikipedia.org/w/load.php...ia.org/w/load.php200.4 KB815.0 KB
https://auth.wikimedia.org/metawiki/wiki/Special:CentralAutoLogin/checkLoggedIn...gin/checkLoggedIn1.4 KB254 B
https://meta.wikimedia.org/w/index.php...a.org/w/index.php4.5 KB11.5 KB
warn(70)Don't use private headers on static contentprivateAssets

The page has 4 requests with private headers. The main page has a private header. It could be right in some cases where the user can be logged in and served specific content. But if your asset is static it should never be private. Make sure that the assets really should be private and only used by one user. Otherwise, make it cacheable for everyone.

If you set private headers on content, that means that the content are specific for that user. Static content should be able to be cached and used by everyone. Avoid setting the cache header to private.

Offenders
infoAdd decoding="async" to non-critical imagesdecodingAsync

The page has 6 images (out of 23) 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
infoLong cache headers is goodcacheHeadersLong
warn(90)Avoid doing redirectsassetsRedirects

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

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

Offenders
warn(95)Inline CSS for faster first renderinlineCss

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

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

warn(99)Avoid slowing down the critical rendering pathavoidRenderBlocking

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

72
1 error3 info
error(0)Cumulative Layout ShiftcumulativeLayoutShift

You have a poor cumulative layout shift score (0.6870). It is in the Google Web Vitals poor range, with a shift higher than 0.25. You should manually check the filmstrip or video and check if it will affect the user.

Cumulative Layout Shift measures the sum total of all individual layout shift scores for unexpected layout shift that occur. The metric is measuring visual stability by quantify how often users experience unexpected layout shifts. It is one of Google Web Vitals.

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 18 responses that sets both a max-age and expires header. There are 42 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://en.wikipedia.org/wiki/Main_Page has a header content-security-policy that is 4501 characters long. https://en.wikipedia...ia.org/w/load.php has a header sourcemap that is 1215 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

Page info

TitleWikipedia, the free encyclopedia
GeneratorMediaWiki 1.47.0-wmf.3
Width360
Height8707
DOM elements2024
Avg DOM depth12
Max DOM depth21
Iframes0
Script tags8
Local storage744.4 KB
Session storage0 b
Network Information API4g

Resource hints

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

Technologies used to build the page

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

Detected technologies

4 technologies
Visual Metrics | Google Web Vitals | Largest Contentful Paint | Cumulative Layout Shift | Browser metrics | Long Aninimation Frames | Visual Elements | Server timings | 

Data from run 1

Visual Metrics

Visual progress
Visual progress at 0 s0.0s
Visual progress at 1 s1.0s
Visual progress at 1.3 s1.3s
Visual progress at 1.6 s1.6s
Visual progress at 1.9 s1.9s
Visual progress at 2.2 s2.2s
Visual progress at 2.5 s2.5s
Visual progress at 2.8 s2.8s
FCP0.77s
LCP1.12s
VC852.63s
Long tasks
0.0s0.6s1.1s1.7s2.2s2.8s

Google Web Vitals

from run 1

Largest Contentful Paint

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

1.120 sLCP render time

Phase breakdown

  • TTFB395 ms
  • Resource load delay0 ms
  • Resource load duration0 ms
  • Element render delay725 ms

Element

Element type
<p>
Size (w × h)
67980
Load time
0 ms
Recalculate-style elements before LCP
273 (83.05 ms)

DOM path

body > div#mw-mf-viewport > div#mw-mf-page-center > main#content > div#bodyContent > div#mw-content-text > div:eq(1) > section#mwAQ > div#mp-upper > div#mp-left > div#mp-tfa > p
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.

0.687cumulative layout shift score

Elements that shifted

Sorted by individual shift score (higher = bigger shift). The top entries usually account for most of the page's CLS.

  • #10.376<div id="mw-mf-page-center"></div>
    body > div#mw-mf-viewport > div#mw-mf-page-center
  • #20.311<div id="bodyContent" class="content"></div>
    body > div#mw-mf-viewport > div#mw-mf-page-center > main#content > div#bodyContent
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
First Contentful Paint info
Elements that needed recalculate style before FCP83
Time spent in recalculate style before FCP43.471 ms
Extra timings
User Timing marks
mwStartup771 ms
mwCentralNoticeBanner2.556 s

Long Animation Frames

A long animation frame (LOAF) is a frame that took ≥ 50 ms from input to the next paint. The breakdown shows where that time went. Read more about the Long Animation Frames API.

Showing the top 10 longest animation frames.

Long animation frame #1
900.1 ms
  • Blocking388.6 ms
  • Work269.1 ms
  • Render242.4 ms
  • Pre-layout233.4 ms
  • Style & layout9 ms

Scripts that ran during this frame

Invoker
IdleRequestCallback
Invoker type
user-callback
Source function
doPropagation
Window attribution
self
Source char position
4314
Invoker
FrameRequestCallback
Invoker type
user-callback
Source function
flushCssBuffer
Window attribution
self
Source char position
3240
Long animation frame #2
408.8 ms
  • Blocking146.1 ms
  • Work101.7 ms
  • Render161 ms
  • Pre-layout159.4 ms
  • Style & layout1.6 ms

Scripts that ran during this frame

Forced style and layout
56 ms
Invoker
FrameRequestCallback
Invoker type
user-callback
Source function
flushCssBuffer
Window attribution
self
Source char position
3240
Long animation frame #3
218.5 ms
  • Blocking72 ms
  • Work85.9 ms
  • Render60.6 ms
  • Pre-layout37.6 ms
  • Style & layout23 ms

Scripts that ran during this frame

Invoker
IdleRequestCallback
Invoker type
user-callback
Source function
doPropagation
Window attribution
self
Source char position
4314
Invoker
FrameRequestCallback
Invoker type
user-callback
Source function
flushCssBuffer
Window attribution
self
Source char position
3240
Long animation frame #4
185.3 ms
  • Blocking67.7 ms
  • Work117.7 ms
  • Render0 ms
  • Pre-layout0 ms
  • Style & layout0 ms

Scripts that ran during this frame

Invoker
IdleRequestCallback
Invoker type
user-callback
Source function
flushWrites
Window attribution
self
Source char position
19340
Long animation frame #5
154.9 ms
  • Blocking40.3 ms
  • Work35.1 ms
  • Render79.5 ms
  • Pre-layout0 ms
  • Style & layout79.5 ms

No script attribution available for this frame.

Long animation frame #6
319.2 ms
  • Blocking30 ms
  • Work286.7 ms
  • Render2.5 ms
  • Pre-layout2.4 ms
  • Style & layout0.1 ms

Scripts that ran during this frame

Invoker
https://en.wikipedia.org/wiki/Main_Page
Invoker type
classic-script
Window attribution
self
Long animation frame #7
181.2 ms
  • Blocking10.8 ms
  • Work168.9 ms
  • Render1.5 ms
  • Pre-layout0 ms
  • Style & layout1.5 ms

Scripts that ran during this frame

Invoker
https://en.wikipedia.org/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=minerva
Invoker type
classic-script
Window attribution
self
Long animation frame #8
99.4 ms
  • Blocking7 ms
  • Work75.3 ms
  • Render17.1 ms
  • Pre-layout15.7 ms
  • Style & layout1.4 ms

Scripts that ran during this frame

Invoker
https://en.wikipedia.org/w/load.php?lang=en&modules=ext.centralNotice.bannerHistoryLogger%2CchoiceData%2Cdisplay%2CgeoIP%2CimpressionDiet%2CkvStore%2ClargeBannerLimit%2ClegacySupport%2CstartUp%7Cext.centralauth.ForeignApi%2Ccentralautologin%7Cext.checkUser.clientHints%7Cext.cx.entrypoints.languagesearcher.init%7Cext.cx.entrypoints.mffrequentlanguages%7Cext.cx.eventlogging.campaigns%7Cext.cx.model%7Cext.echo.centralauth%7Cext.eventLogging%2CnavigationTiming%2Cpopups%2CtestKitchen%2CwikimediaEvents%7Cext.eventLogging.metricsPlatform%7Cext.growthExperiments.SuggestedEditSession%7Cext.parsermigration.survey%7Cext.urlShortener.toolbar%7Cext.wikimediaEvents.testKitchen%7Cjquery%2Coojs%2Csite%7Cjquery.client%2CtextSelection%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.ready%7Cmediawiki.page.watch.ajax%7Cmediawiki.template.mustache%7Cmobile.codex.styles%7Cmobile.init%2Cstartup%7Cmw.cx.SiteMapper%7Cmw.externalguidance.init%7Cskins.minerva.scripts%7Cwikibase.databox.fromWikidata&skin=minerva&version=1i9bw
Invoker type
classic-script
Window attribution
self
Long animation frame #9
75.8 ms
  • Blocking6.9 ms
  • Work22.2 ms
  • Render46.7 ms
  • Pre-layout46.7 ms
  • Style & layout0 ms

No script attribution available for this frame.

Server timings

2 entries
NameDurationDescription
cache0 mshit-front
host0 mscp3070

Custom metrics collected through JavaScript

There are no custom configured scripts.

Extra metrics collected using scripting

There are no custom extra metrics from scripting.

Visual Elements2
LargestImage250px-Sally_Ride_%281984%29.jpg
Display time2.700 s
Position (x, y)118, 501
Size (w × h)125 × 156
HTML snippet
<img alt="Sally Ride" resource="//en.wikipedia.org/wiki/File:Sally_Ride_(1984).jpg" src="//upload.wikimedia.org/wikipedia/commons/thumb/0/0c/Sally_Ride_%281984%29.jpg/250px-Sally_Ride_%281984%29.jpg" decoding="async" data-file-width="2790" data-file-height="3487" data-file-type="bitmap" height="156" width="125" class="mw-file-element">
LargestImage preview
Heading
Display time2.700 s
Position (x, y)48, 317
Size (w × h)256 × 28
HTML snippet
<h1 class="html-heading mw-html-heading" id="Welcome_to_Wikipedia"></h1>
Summary | Largest responses | Per content type | Per domain | Expires & last-modified | After onLoad | Render-blocking | 

PageXray

How the page is built.

HTTP versionHTTP/2.0
Total requests42
Total domains5
Transfer size1.0 MB
Content size2.0 MB
Missing compression0
Cookies260 third-party

Response codes

200
3992.9%
201
12.4%
204
12.4%
302
12.4%

Requests and sizes per content type

8 types
ContentHeader SizeTransfer SizeContent SizeRequests
html0 b53.2 KB224.8 KB1
css0 b22.4 KB155.0 KB2
javascript0 b238.9 KB919.7 KB6
image0 b717.1 KB696.1 KB19
favicon0 b1.8 KB2.7 KB1
svg0 b13.7 KB12.3 KB9
json0 b1.8 KB263 B1
plain0 b1.6 KB0 b2
Total0 b1.0 MB2.0 MB41

Data per domain

5 domains
DomainTotal download timeTransfer SizeContent SizeRequests
en.wikipedia.org3.513 s328.5 KB1.3 MB21
upload.wikimedia.org11.702 s715.1 KB694.8 KB18
auth.wikimedia.org186 ms1.4 KB254 B1
meta.wikimedia.org102 ms4.5 KB11.5 KB1
intake-analytics.wikimedia.org329 ms1.0 KB0 b1

Expires & last-modified statistics

typeminmedianmax
Expires0 seconds0 seconds1 year
Last modified11 seconds6 weeks2 years

Requests loaded after onLoad event

2 requests

Includes requests done after load event end.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript0 b0
image2.0 KB1
font0 b0
favicon1.8 KB1
Total3.8 KB2

Requests loaded after onContentLoad

5 requests

Includes requests done after DOM content loaded.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript0 b0
image62.2 KB2
font0 b0
favicon1.8 KB1
plain1.6 KB2
Total65.6 KB5

Render blocking requests

9 assets

Render blocking information directly from Chrome.

BlockingIn body parser blockingPotentially blocking
201
Long tasks | Per script blocking | Where time went | Forced reflows | Forced layout/script | Per script | Animations | 

CPU

539 ms of 727 ms total — defer it, replace it with a lighter alternative, or move its work off the main thread to recover most of your TBT.

Download the Chrome trace and drag-and-drop it into Performance in DevTools.

Long tasks

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

TBT637 ms
Max FID261 ms
Total long tasks11
Total time1.227 s
Last task at3.544 s
Before FP90 ms1 task
Before FCP90 ms1 task
Before LCP239 ms3 tasks
After load119 ms1 task

Blocking time per script

How much each script blocked the main thread, derived from the Long Animation Frame API. The script that started each long frame is credited with the frame's blocking time — 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

Where the time went

Calculated from the Chrome trace.

Categories

2.711 s total
scriptEvaluation1.001 s36.9%
other774 ms28.6%
styleLayout513 ms18.9%
parseHTML214 ms7.9%
paintCompositeRender171 ms6.3%
scriptParseCompile24 ms0.9%
garbageCollection14 ms0.5%

Forced reflows

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

Scripts causing reflows

2 reflows ≥ 2 ms across 2 scripts

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.

CPU time per script