Page summary

Summary

Metric	Value
Page metrics
Performance Score	73
Total Page Transfer Size	630.0 KB
Requests	34
Timing metrics
TTFB [median]	437 ms
First Paint [median]	932 ms
Fully Loaded [median]	4.078 s
Google Web Vitals
TTFB [median]	437 ms
First Contentful Paint (FCP) [median]	932 ms
Largest Contentful Paint (LCP) [median]	1.424 s
Cumulative Layout Shift (CLS) [median]	0.00
Interaction To Next Paint (INP) [median]	120 ms
Total Blocking Time [median]	1.235 s
Max Potential FID [median]	258 ms
CPU metrics
CPU long tasks [median]	14
CPU longest task duration	292 ms
CPU last long task happens at	3.760 s
Visual Metrics
First Visual Change [median]	967 ms
Speed Index [median]	2.122 s
Visual Complete 85% [median]	3.534 s
Visual Complete 99% [median]	3.900 s
Last Visual Change [median]	3.900 s

Timings Summary

Waterfall

Run 2 SpeedIndex median

Video

Filmstrip

Use--filmstrip.showAll to show all filmstrips.

0 s

0.8 sCPU Long Task duration 155 ms

1 sFirst Contentful Paint 932 msFirst Visual Change 967 msLargest Image 967 ms

1.1 s

1.2 smwStartup 1.103 sCPU Long Task duration 258 ms

1.3 s

1.4 s

1.5 sLCP <P> 1.448 sCPU Long Task duration 58 ms

1.6 s

1.7 sCPU Long Task duration 230 ms

1.8 s

1.9 s

2 sCPU Long Task duration 168 ms

2.1 sCPU Long Task duration 50 ms

2.2 sCPU Long Task duration 143 ms

2.3 s

2.4 sCPU Long Task duration 68 ms

2.5 sDOM Content Loaded Time 2.415 sCPU Long Task duration 136 ms

2.6 s

2.7 sCPU Long Task duration 85 ms

2.8 sCPU Long Task duration 228 ms

2.9 s

3 s

3.1 sCPU Long Task duration 207 ms

3.2 s

3.3 s

3.4 smwCentralNoticeBanner 3.329 sCPU Long Task duration 98 ms

3.5 sHeading 3.467 s

3.6 sPage Load Time 3.513 sVisual Complete 85% 3.534 sVisual Complete 95% 3.567 s

3.7 s

3.8 sCPU Long Task duration 116 ms

3.9 s

4 sLast Visual Change 3.934 sVisual Complete 99% 3.934 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 8.1.1.

Coach score

• Total score 80
• Performance score 73
• Privacy score 88
• Best practice score 89

Performance advice (73)

Show/hide details

Title	Advice	Score
Avoid slowing down the critical rendering path (avoidRenderBlocking)	The page has 3 blocking requests and 0 in body parser blocking (0 JavaScript and 3 CSS). There are 1 potentially render blocking requests. You need to verify if it is render blocking: https://vi.m.wikipedia.org/w/load.php?lang=vi&modules=startup&only=scripts&raw=1&skin=minerva	99
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://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php
Don't scale images in the browser (avoidScalingImages)	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.	80
Description: 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: https://vi.m.wikipedia.org/static/images/mobile/copyright/wikipedia-wordmark-en.svg https://vi.m.wikipedia.org/static/images/mobile/copyright/wikipedia-wordmark-en.svg
Inline CSS for faster first render (inlineCss)	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.	95
Description: 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.
Avoid CPU Long Tasks (longTasks)	The page has 14 CPU long tasks with the total of 2.069 s. The total blocking time is 1.263 s and 1 long task before first contentful paint with total time of 156 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.	0
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 unknown self self self self self self self self self self self
Avoid doing redirects (assetsRedirects)	The page has 3 redirects. 1 of the redirects are from the base domain, please fix them! 2 requests are from other domains, it could be 3rd-party assets doing unnecessary redirects. :(	70
Description: 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: https://vi.m.wikipedia.org/wiki/Special:CentralAutoLogin/start?type=script&usesul3=1&urlversion=2 https://meta.wikimedia.org/w/index.php...a.org/w/index.php https://auth.wikimedia.org/loginwiki/wiki/Special:CentralAutoLogin/checkLoggedIn...gin/checkLoggedIn
Avoid extra requests by setting cache headers (cacheHeaders)	The page has 10 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 183.4 kB the next access.	0
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/commons/thumb/4/4c/Vincent_van_Gogh_-_Sel..._%28454045%29.jpg https://upload.wikimedia.org/wikipedia/commons/thumb/c/cd/Vincent_van_Gogh_signa...incent%29.svg.png https://vi.m.wikipedia.org/wiki/Special:CentralAutoLogin/start?type=script&usesul3=1&urlversion=2 https://meta.wikimedia.org/w/index.php...a.org/w/index.php https://auth.wikimedia.org/loginwiki/wiki/Special:CentralAutoLogin/checkLoggedIn...gin/checkLoggedIn https://meta.m.wikimedia.org/w/index.php...a.org/w/index.php https://login.wikimedia.org/wiki/Special:CentralAutoLogin/checkLoggedIn...gin/checkLoggedIn https://upload.wikimedia.org/wikipedia/foundation/2/20/CloseWindow19x19.png https://upload.wikimedia.org/wikipedia/commons/3/39/WLE_Austria_Logo_%28text_right%29.svg https://upload.wikimedia.org/wikipedia/commons/thumb/4/44/WLE_Germany_banner_202...y_banner_2023.jpg
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://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php?lang=vi&modules=startup&only=scripts&raw=1&skin=minerva https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php?lang=vi&modules=site.styles&only=styles&skin=minerva https://vi.m.wikipedia.org/w/api.php?action=webapp-manifest
Always compress text content (compressAssets)	The page has 1 request that are served uncompressed. You could save a lot of bytes by sending them compressed instead.	90
Description: 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: URL Transfer size Content size https://meta.m.wikimedia.org/w/index.php...a.org/w/index.php 2.6 KB 4.1 KB
Total JavaScript size shouldn't be too big (javascriptSize)	The total JavaScript transfer size is 320.6 kB and the uncompressed size is 1.3 MB. This is totally crazy! There is really room for improvement here.	0
Description: 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: URL Transfer size Content size https://vi.m.wikipedia.org/w/load.php?lang=vi&modules=startup&only=scripts&raw=1&skin=minerva 20.0 KB 59.7 KB https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php 25.6 KB 81.0 KB https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php 259.9 KB 1.0 MB https://meta.m.wikimedia.org/w/index.php...a.org/w/index.php 2.6 KB 4.1 KB https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php 3.7 KB 12.7 KB https://login.wikimedia.org/wiki/Special:CentralAutoLogin/checkLoggedIn...gin/checkLoggedIn 1.4 KB 254 B
Make each CSS response small (optimalCssSize)	https://vi.m.wikipedia.org/w/load.php?lang=vi&modules=ext.cite.styles%7Cext.phonos.icons%2Cstyles%7Cext.relatedArticles.styles%7Cext.wikimediaBadges%7Cext.wikimediamessages.styles%7Cmediawiki.hlist%7Cmediawiki.page.gallery.styles%7Cmobile.init.styles%7Cskins.minerva.codex.styles%7Cskins.minerva.content.styles.images%7Cskins.minerva.icons%2Cstyles%7Cwikibase.client.init&only=styles&skin=minerva size is 20.9 kB (20909) and that is bigger than the limit of 14.5 kB. Try to make the CSS files fit into 14.5 KB.	90
Description: Make CSS responses small to fit into the magic number TCP window size of 14.5 KB. The browser can then download the CSS faster and that will make the page start rendering earlier.
Offenders: URL Transfer size Content size https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php 20.4 KB 153.6 KB
Don't use private headers on static content (privateAssets)	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.	80
Description: 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: https://vi.m.wikipedia.org/wiki/Vincent_van_Gogh https://vi.m.wikipedia.org/wiki/Special:CentralAutoLogin/start?type=script&usesul3=1&urlversion=2 https://login.wikimedia.org/wiki/Special:CentralAutoLogin/checkLoggedIn...gin/checkLoggedIn

Best practice advice (89)

Show/hide details

Title	Advice	Score
Meta description (metaDescription)	The page is missing a meta description.	0
Description: Use a page description to make the page more relevant to search engines.
Do not send too long headers (longHeaders)	https://vi.m.wikiped...ia.org/w/load.php has a header sourcemap that is 1213 characters long.	99
Description: Do not send response headers that are too long.
Offenders: https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php
Avoid unnecessary headers (unnecessaryHeaders)	There are 23 responses that sets both a max-age and expires header. There are 34 responses that sets a server header.	43
Description: 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: https://vi.m.wikipedia.org/wiki/Vincent_van_Gogh https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php?lang=vi&modules=startup&only=scripts&raw=1&skin=minerva https://vi.m.wikipedia.org/w/load.php?lang=vi&modules=startup&only=scripts&raw=1&skin=minerva https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php?lang=vi&modules=site.styles&only=styles&skin=minerva https://vi.m.wikipedia.org/w/load.php?lang=vi&modules=site.styles&only=styles&skin=minerva https://upload.wikimedia.org/wikipedia/commons/thumb/4/4c/Vincent_van_Gogh_-_Sel..._%28454045%29.jpg https://vi.m.wikipedia.org/static/images/mobile/copyright/wikipedia-wordmark-en.svg https://vi.m.wikipedia.org/static/images/mobile/copyright/wikipedia-wordmark-en.svg https://upload.wikimedia.org/wikipedia/commons/thumb/c/cd/Vincent_van_Gogh_signa...incent%29.svg.png https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/wiki/Special:CentralAutoLogin/start?type=script&usesul3=1&urlversion=2 https://meta.wikimedia.org/w/index.php...a.org/w/index.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://auth.wikimedia.org/loginwiki/wiki/Special:CentralAutoLogin/checkLoggedIn...gin/checkLoggedIn https://meta.m.wikimedia.org/w/index.php...a.org/w/index.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://vi.m.wikipedia.org/w/load.php...ia.org/w/load.php https://login.wikimedia.org/wiki/Special:CentralAutoLogin/checkLoggedIn...gin/checkLoggedIn https://upload.wikimedia.org/wikipedia/foundation/2/20/CloseWindow19x19.png https://upload.wikimedia.org/wikipedia/commons/3/39/WLE_Austria_Logo_%28text_right%29.svg https://upload.wikimedia.org/wikipedia/commons/thumb/4/44/WLE_Germany_banner_202...y_banner_2023.jpg https://vi.m.wikipedia.org/w/api.php?action=webapp-manifest https://vi.m.wikipedia.org/w/api.php?action=webapp-manifest https://vi.m.wikipedia.org/static/favicon/wikipedia.ico https://vi.m.wikipedia.org/static/favicon/wikipedia.ico https://vi.m.wikipedia.org/static/apple-touch/wikipedia.png https://vi.m.wikipedia.org/static/apple-touch/wikipedia.png

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://vi.m.wikipedia.org/wiki/Vincent_van_Gogh
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://vi.m.wikipedia.org/wiki/Vincent_van_Gogh

Page info

Page info
Title	Vincent van Gogh – Wikipedia tiếng Việt
Generator	MediaWiki 1.45.0-wmf.5
Width	361
Height	7225
DOM elements	4577
Avg DOM depth	12
Max DOM depth	19
Iframes	0
Script tags	7
Local storage	752.9 KB
Session storage	0 b
Network Information API	4g

Resource Hints
dns-prefetch
https://meta.wikimedia.org/
https://vi.m.wikipedia.org/wiki/auth.wikimedia.org
preconnect
https://upload.wikimedia.org/

Technologies used to build the page.

Data collected using Wappalyzer version 6.10.66. 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
MediaWiki	100	Wikis
PHP	100	Programming languages
HSTS	100	Security

Data from run 2

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	P
Element/tag	<p></p>
Render time	1.448 s
Element render delay	1.011 s
TTFB	437 ms
Resource delay	0 ms
Resource load duration	0 ms
Elements that needed recalculate style before LCP	482
Time spent in recalculate style before LCP	95.19 ms
Load time	0 ms
Size (width*height)	102678
DOM path
div#mw-mf-viewport > div#mw-mf-page-center > main#content > div#bodyContent > div#mw-content-text > div:eq(0) > section#mf-section-0 > p:eq(1)> div#mw-mf-viewport > div#mw-mf-page-center > main#content > div#bodyContent > div#mw-content-text > div:eq(0) > section#mf-section-0 > p:eq(1)>

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.

Detected Cumulative Layout Shift

No layout shift detected.

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 3.760 s

Individual Long Tasks

CPU time spent

Calculated using Tracium.

Time spent per request