Page summary

Summary

Metric	Value
Page metrics
Performance Score	95
Total Page Transfer Size	76.6 KB
Requests	8
Timing metrics
TTFB [median]	489 ms
First Paint [median]	926 ms
Fully Loaded [median]	1.012 s
Google Web Vitals
TTFB [median]	489 ms
First Contentful Paint (FCP) [median]	926 ms
Largest Contentful Paint (LCP) [median]	926 ms
Cumulative Layout Shift (CLS) [median]	0.00
CPU metrics
CPU long tasks [median]	2
CPU longest task duration	338 ms
CPU last long task happens at	646 ms
Visual Metrics
First Visual Change [median]	933 ms
Speed Index [median]	1.814 s
Visual Complete 85% [median]	933 ms
Visual Complete 99% [median]	7.433 s
Last Visual Change [median]	10.866 s

Timings Summary

Waterfall

Run 5 SpeedIndex median

Video

Filmstrip

Use--filmstrip.showAll to show all filmstrips.

0 s

0.6 sCPU Long Task duration 134 ms

0.7 sCPU Long Task duration 220 ms

0.9 sLayout Shift 0.00031 863 ms

1 sDOM Content Loaded Time 901 msFirst Contentful Paint 914 msLCP <IMG> 914 msPage Load Time 920 msFirst Visual Change 933 msLargest Image 933 msVisual Complete 85% 966 msHeading 966 ms

1.1 sFully Loaded 1.022 s

1.2 s

1.3 s

1.9 s

2.5 s

3.1 s

3.7 s

4.3 s

4.9 s

5.5 s

6.1 s

6.7 s

7.3 s

7.5 sVisual Complete 95% 7.433 sVisual Complete 99% 7.433 s

7.6 s

7.9 s

8.5 s

9.1 s

9.7 s

10.3 s

10.9 sLast Visual Change 10.866 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 8.0.2.

Coach score

• Total score 94
• Performance score 95
• Privacy score 88
• Best practice score 100

Performance advice (95)

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-10f5326740.js https://www.wikipedia.org/portal/wikipedia.org/assets/js/gt-ie9-ce3fe8e88d.js
Have a fast largest contentful paint (largestContentfulPaint)	You can add fetchPriority="high" to the image to increase the load priority in Chrome.	95
Description: Largest contentful paint is one of Google Web Vitals and reports the render time of the largest image or text block visible within the viewport, relative to when the page first started loading. To be fast according to Google, it needs to render before 2.5 seconds and results over 4 seconds is poor performance.
Avoid CPU Long Tasks (longTasks)	The page has 2 CPU long tasks with the total of 361 ms. The total blocking time is 0 ms and 2 long tasks before first contentful paint with total time of 361 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.	60
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 unknown
Avoid extra requests by setting cache headers (cacheHeaders)	The page has 1 request that are missing a cache time. Configure a cache time so the browser doesn't need to download them every time. It will save 2.9 kB the next access.	90
Description: 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: https://upload.wikimedia.org/wikipedia/donate/1/14/Wikimedia_Foundation_logo_-_wordmark.svg
Long cache headers is good (cacheHeadersLong)	The page has 5 requests that have a shorter cache time than 30 days (but still a cache time).	95
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/img/sprite-de847d1a.svg https://www.wikipedia.org/portal/wikipedia.org/assets/js/index-10f5326740.js https://www.wikipedia.org/portal/wikipedia.org/assets/js/gt-ie9-ce3fe8e88d.js https://www.wikipedia.org/portal/wikipedia.org/assets/img/Wikinews-logo_sister.png

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	1193
DOM elements	1127
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 Wappalyzerversion 6.10.66.  Use --browsertime.firefox.includeResponseBodies htmlor --browsertime.chrome.includeResponseBodies htmlto help Wappalyser find more information about technologies used.

Technology	Confidence	Category
Apache Traffic Server 9.2.5	100	Web servers
HSTS	100	Security

Data from run 5

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	IMG
Element/tag	<img class="central-featured-logo" src="portal/wikipedia.org/assets/img/Wikipedia-logo-v2.png" srcset="portal/wikipedia.org/assets/img/Wikipedia-logo-v2@1.5x.png 1.5x, portal/wikipedia.org/assets/img/Wikipedia-logo-v2@2x.png 2x" width="200" height="183" alt="">
Render time	914 ms
Elements that needed recalculate style before LCP	1734
Time spent in recalculate style before LCP	24.607 ms
Load time	640 ms
URL	https://www.wikipedi...pedia-logo-v2.png
Size (width*height)	36600
DOM path
main > div:eq(0) > img> main > div:eq(0) > img>

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

0.00031 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
0.00031	<div class="central-textlogo"></div>,<img class="central-featured-logo" src="portal/wikipedia.org/assets/img/Wikipedia-logo-v2.png" srcset="portal/wikipedia.org/assets/img/Wikipedia-logo-v2@1.5x.png 1.5x, portal/wikipedia.org/assets/img/Wikipedia-logo-v2@2x.png 2x" width="200" height="183" alt="">,<div role="search" class="search-container"></div>,<button class="pure-button pure-button-primary-progressive" type="submit"></button>,<button id="js-lang-list-button" aria-expanded="false" aria-controls="js-lang-lists" class="lang-list-button"></button>
body#www-wikipedia-org > main > div:eq(0),body#www-wikipedia-org > main > div:eq(0) > img,body#www-wikipedia-org > main > div:eq(1),body#www-wikipedia-org > main > div:eq(1) > form#search-form > fieldset > button,body#www-wikipedia-org > main > nav:eq(1) > div:eq(0) > button#js-lang-list-button

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 646 ms

Individual Long Tasks

CPU time spent

Calculated using Tracium.

Time spent per request