Page summary

Summary

Metric	Value
Page metrics
Performance Score	98
Total Page Transfer Size	254.3 KB
Requests	9
Timing metrics
TTFB [median]	489 ms
First Paint [median]	896 ms
Fully Loaded [median]	1.142 s
Google Web Vitals
TTFB [median]	489 ms
First Contentful Paint (FCP) [median]	896 ms
Largest Contentful Paint (LCP) [median]	1.072 s
Cumulative Layout Shift (CLS) [median]	0.00
CPU metrics
CPU long tasks [median]	1
CPU longest task duration	308 ms
CPU last long task happens at	533 ms
Visual Metrics
First Visual Change [median]	900 ms
Speed Index [median]	1.733 s
Visual Complete 85% [median]	1.000 s
Visual Complete 99% [median]	11.600 s
Last Visual Change [median]	11.633 s

Timings Summary

Waterfall

Run 4 SpeedIndex median

Video

Filmstrip

Use--filmstrip.showAll to show all filmstrips.

0 s

0.6 sCPU Long Task duration 297 ms

0.9 sDOM Content Loaded Time 859 msFirst Visual Change 866 msHeading 866 msLayout Shift 0.00003 886 msFirst Contentful Paint 888 ms

1 sLCP <VIDEO> wikipedia25-video 1.000 sVisual Complete 85% 1.000 s

1.1 sPage Load Time 1.024 s

1.2 sFully Loaded 1.141 s

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9.2 sVisual Complete 95% 9.200 s

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11.7 sLast Visual Change 11.633 sVisual Complete 99% 11.633 s

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 8.1.3.

Coach score

• Total score 95
• Performance score 98
• Privacy score 88
• Best practice score 100

Performance advice (98)

Show/hide details

Title	Advice	Score
Avoid slowing down the critical rendering path (avoidRenderBlocking)	The page has 1 blocking requests and 1 in body parser blocking (2 JavaScript and 0 CSS).	80
Description: 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: https://www.wikipedia.org/portal/wikipedia.org/assets/js/index-90de98612a.js https://www.wikipedia.org/portal/wikipedia.org/assets/js/gt-ie9-507b16b6be.js
Avoid CPU Long Tasks (longTasks)	The page has 1 CPU long task with the total of 299 ms. The total blocking time is 0 ms and 1 long task before first contentful paint with total time of 299 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.	80
Description: 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
Long cache headers is good (cacheHeadersLong)	The page has 7 requests that have a shorter cache time than 30 days (but still a cache time).	93
Description: Setting a cache header is good. Setting a long cache header (at least 30 days) is even better beacause then it will stay long in the browser cache. But what do you do if that asset change? Rename it and the browser will pick up the new version.
Offenders: https://www.wikipedia.org/portal/wikipedia.org/assets/img/Wikipedia-logo-v2.png https://www.wikipedia.org/portal/wikipedia.org/assets/js/index-90de98612a.js https://www.wikipedia.org/portal/wikipedia.org/assets/js/gt-ie9-507b16b6be.js https://www.wikipedia.org/portal/wikipedia.org/assets/img/sprite-e49fbf32.svg https://www.wikipedia.org/portal/wikipedia.org/assets/img/Wikinews-logo_sister.png https://www.wikipedia.org/portal/wikipedia.org/assets/img/wikipedia25-synthesizer-poster-light.webp https://www.wikipedia.org/portal/wikipedia.org/assets/img/wikipedia25-synthesizer-idle-light.webm

Best practice advice (100)

Your best practice score is perfect!

Privacy advice (88)

Show/hide details

Title	Advice	Score
Use a good Content-Security-Policy header to make sure you you avoid Cross Site Scripting (XSS) attacks. (contentSecurityPolicyHeader)	Set a Content-Security-Policy header to make sure you are not open for Cross Site Scripting (XSS) attacks. You can start with setting a Content-Security-Policy-Report-Only header, that will only report the violation, not stop the download.	0
Description: Content Security Policy is delivered via a HTTP response header, and defines approved sources of content that the browser may load. It can be an effective countermeasure to Cross Site Scripting (XSS) attacks and is also widely supported and usually easily deployed. https://scotthelme.co.uk/content-security-policy-an-introduction/.
Offenders: https://www.wikipedia.org/
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.	0
Description: 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: https://www.wikipedia.org/

Page info

Page info
Title	Wikipedia
Width	1904
Height	1300
DOM elements	1098
Avg DOM depth	9
Max DOM depth	12
Iframes	0
Script tags	4
Local storage	94 B
Session storage	0 b
Network Information API	4g

Resource Hints
preconnect
https://upload.wikimedia.org/
https://en.wikipedia.org/

Technologies used to build the page.

Data collected using Wappalyzer version 6.10.54. With updated code from Webappanalyzer 2024-12-27. Use --browsertime.firefox.includeResponseBodies htmlor --browsertime.chrome.includeResponseBodies htmlto help Wappalyzer find more information about technologies used.

Technology	Confidence	Category
Apache Traffic Server 9.2.11	100	Web servers
HSTS	100	Security

Data from run 4

Visual Metrics

Browser Metrics

Largest Contentful Paint

When in time the page main content is rendered (collected using the Largest Contentful Paint API). Read more about Largest Contentful Paint.

Element type	VIDEO
Element/tag	<video id="wikipedia25-video" class="wikipedia25-video" data-idle-light="portal/wikipedia.org/assets/img/wikipedia25-synthesizer-idle-light.webm" data-idle-dark="portal/wikipedia.org/assets/img/wikipedia25-synthesizer-idle-dark.webm" data-click-light="portal/wikipedia.org/assets/img/wikipedia25-synthesizer-click-light.webm" data-click-dark="portal/wikipedia.org/assets/img/wikipedia25-synthesizer-click-dark.webm" data-poster-light="portal/wikipedia.org/assets/img/wikipedia25-synthesizer-poster-light.webp" data-poster-dark="portal/wikipedia.org/assets/img/wikipedia25-synthesizer-poster-dark.webp" width="200" height="200" autoplay="" loop="" muted="" playsinline="" poster="portal/wikipedia.org/assets/img/wikipedia25-synthesizer-poster-light.webp" src="portal/wikipedia.org/assets/img/wikipedia25-synthesizer-idle-light.webm"></video>
Render time	1.000 s
Element render delay	40 ms
TTFB	489 ms
Resource delay	354 ms
Resource load duration	117 ms
Elements that needed recalculate style before LCP	2078
Time spent in recalculate style before LCP	33.818 ms
Element id	wikipedia25-video
Load time	960 ms
URL	https://www.wikipedi...poster-light.webp
Size (width*height)	40000
DOM path
main > div:eq(1) > video#wikipedia25-video> main > div:eq(1) > video#wikipedia25-video>

The largest contentful paint is highlighted in the image. If no element is highlighted the element was removed before the screenshot or the LCP API couldn't find the element.

The Largest Contentful Paint API highlighted this image as a part of the LCP.

Detected Cumulative Layout Shift

0.00003 cumulative layout shift collected from the Cumulative Layout Shift API.

These HTML elements contribute most to the Cumulative Layout Shifts of the page. The higher score, the more layout shift.

Score	HTML Element
0.00003	<div class=" styled-select js-enabled"></div>
body#www-wikipedia-org > main > div:eq(4) > form#search-form > fieldset > div#search-input > div:eq(0)

The elements that have shifted place is highlighted in the image (that have a higher value than 0.01). If the element shifted outside of the viewport, you will not see it there. It can be hard to understand what content that has shifted, if that's the case, checkout the video or the filmstrip of the run.

Long Animation Frames

Read more about the Long Animation Frames API here here.

The top 10 longest animation frames entries

Server timings

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 Elements

PageXray

How the page is built.

Largest assets on the page (by transfer size)

Requests and sizes per content type

Data per domain

Expires and last modified statistics

Requests loaded after onLoad event

Included requests done after load event end.

Requests loaded after onContentLoad

Includes requests done after DOM content loaded.

Render blocking requests

Render blocking information directly from Chrome.

Render information

CPU

Download the Chrome trace log and drag and drop it into Developer Tools / Performance in Chrome.

Long Tasks

Collected using the Long Task API. A long task is a task that take 50 milliseconds or more.

CPU last long task happened at 533 ms

Individual Long Tasks

CPU time spent

Calculated using Tracium.