https://query.wikidata.org/querybuilder/
Tested 2026-07-28 02:33:38 using Chrome 150.0.7871.186 (runtime settings)
The red band on the timeline marks when the main thread was busy with long tasks: moments when the page could not paint or respond, however the video looks.
Download videoUse --filmstrip.showAll to show all filmstrips.
Click a frame to seek the video to that moment. The dot marks frames where the page changed visually.
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.
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.
Rendering was not meaningfully delayed. First paint landed at 1.240 s on a 471 ms first byte; the 1 render-blocking request was done by 637 ms and the remaining ~603 ms is style and layout work (74 ms of it measured style recalculation and forced reflows).
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. 26 ms of restyling before the page painted, 2.1 % of the time to First Contentful Paint. Nothing here needs attention.
The recalculation work before first paint is 2.1 % of the time to First Contentful Paint.
JavaScript read a layout value (offsetTop, getBoundingClientRect, …) while the page was mid-change, so the browser had to re-layout synchronously, work that blocks rendering. Reflows before First Contentful Paint delayed the first pixels; reflows before Largest Contentful Paint delayed the main content.
That is 3.9 % of the time to Largest Contentful Paint. The number of reflows matters more than the milliseconds: layout thrashing multiplies on slower devices.
See every forced reflow for the whole page load on the CPU tab
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 gap after the bars is style and layout work.
| Request | When it loaded | Transfer | Download |
|---|---|---|---|
document | 468 ms | 1.9 KB | 467 ms |
index.58783912.cssblocking | 154 ms | 23.8 KB | 154 ms |
0310 ms620 msFCP · LCP 1.240 s |
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.
Most of this is the page being built. Only 22 style recalculations and 16 layout invalidations happened after first paint; the rest is the first render. Not much to chase here.
pseudo: checked2×class: cdx-select-vue--value-selected2×attribute: dir1×Invalidations on a page the user was already looking at, the actionable half.
| Reason | Style recalculations | Layout |
|---|---|---|
| A node was inserted into the page | 6 | – |
| An animation updated stylesAnimate transform and opacity so the compositor can run it off the main thread. | 16 | – |
| An element entered layout | – | 16 |
The page being constructed and styled for the first render. Expected work, shown for scale.
| Reason | Style recalculations | Layout |
|---|---|---|
| JavaScript changed an inline styleSet a class instead of writing element.style, so the browser can batch the work. | 32 | – |
| A node was inserted into the page | 21 | – |
| An animation updated stylesAnimate transform and opacity so the compositor can run it off the main thread. | 8 | – |
| Related style rule | 5 | – |
| A pseudo-class state changed (:hover, :focus, …) | 2 | – |
| A stylesheet rule changed | 1 | – |
| Attribute | 1 | – |
| An element entered layout | – | 265 |
| An element left layout | – | 3 |
| Scrollbar changed | – | 2 |
| An element's size changed | – | 1 |
| Unknown | – | 1 |
11 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.
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.
decodingAsyncThe page has 3 images (out of 3) 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
longTasksThe page has 1 CPU long task with the total of 140 ms. The total blocking time is 0 ms and 1 long task before first contentful paint with total time of 140 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.
cacheHeadersLongThe page has 8 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.
metaDescriptionThe page is missing a meta description.
Use a page description to make the page more relevant to search engines.
unnecessaryHeadersThere are 10 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.
longHeadershttps://query.wikidata.org/favicon.ico has a header content-security-policy-report-only that is 789 characters long.
Do not send response headers that are too long.
referrerPolicyNo <meta name="referrer"> tag was found on the page. Set a Referrer-Policy response header (preferred) or add a meta tag, for example <meta name="referrer" content="strict-origin-when-cross-origin">.
Without an explicit referrer policy the browser falls back to the user-agent default and may leak the full URL of the previous page (including query strings) to every cross-origin request. Set a Referrer-Policy response header (preferred) or a <meta name="referrer"> tag in the document. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Referrer-Policy
contentSecurityPolicyHeaderSet 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
crossOriginEmbedderPolicyHeaderSet 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
crossOriginOpenerPolicyHeaderSet 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
crossOriginResourcePolicyHeaderSet 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
permissionsPolicyHeaderSet 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
referrerPolicyHeaderSet 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/.
xContentTypeOptionsHeaderSet X-Content-Type-Options: nosniff on the document response to prevent MIME-sniffing.
X-Content-Type-Options: nosniff prevents browsers from interpreting files as a different MIME type than what is declared in the Content-Type header. This blocks a class of cross-site scripting and content-type confusion attacks and should be set on every response. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Content-Type-Options
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.
Document
What the page says it is and how large it rendered.
DOM structure
How much markup the browser has to build, style and lay out.
What the page stored on the client, and the network it was tested on.
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.
0.0s1.0s1.1s1.3sWhen the page main content is rendered, collected via the Largest Contentful Paint API. Read more about Largest Contentful Paint.
body > div#app > div#app > div > main > p
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.
How much the page's content shifts as it loads, collected via the Cumulative Layout Shift API.
No layout shifts were detected on this page.
Timing data the server chose to expose through Server-Timing response headers on the main document — typically backend time, cache status or experiment flags.
| Name | Duration | Description |
|---|---|---|
cache | 0 ms | pass |
host | 0 ms | cp3070 |
co_id | 0 ms | 360828044 |
There are no custom configured scripts.
There are no custom extra metrics from scripting.
How the page is built.
https://query.wikidata.org/querybuilder/
| Header | Value |
|---|---|
accept-ranges | bytes |
age | 2 |
cache-control | no-cache |
content-encoding | gzip |
content-type | text/html |
date | Tue, 28 Jul 2026 02:33:39 GMT |
etag | W/"8aa-63a1f22f2d240" |
last-modified | Thu, 17 Jul 2025 12:27:45 GMT |
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" }] } |
server | Apache/2.4.62 (Debian) |
server-timing | cache;desc="pass", host;desc="cp3070",co_id;desc="360828044" |
strict-transport-security | max-age=106384710; includeSubDomains; preload |
vary | Accept-Encoding |
x-analytics | |
x-cache | cp3070 miss, cp3070 pass |
x-cache-status | pass |
x-client-ip | 138.201.135.103 |
x-request-id | 37b2ecb2-1d36-42d0-8924-8f328d153841 |
| URL | Type | Transfer Size | Content Size |
|---|---|---|---|
| https://query.wikida...index.97f88779.js | javascript | 169.5 KB | 524.2 KB |
| https://query.wikida...ndex.58783912.css | css | 23.8 KB | 218.3 KB |
| https://query.wikidata.org/favicon.ico | favicon | 6.5 KB | 14.7 KB |
| https://query.wikida...r/img/QB_Logo.svg | svg | 4.0 KB | 7.6 KB |
| https://query.wikida...lder/i18n/en.json | json | 2.9 KB | 7.4 KB |
| https://query.wikidata.org/querybuilder/ | html | 1.9 KB | 2.2 KB |
| https://query.wikida...der/img/clear.svg | svg | 1.2 KB | 1.0 KB |
| https://query.wikida...er/img/search.svg | svg | 1.1 KB | 494 B |
| https://query.wikida...der/img/close.svg | svg | 1000 B | 321 B |
| https://www.wikidata...org/beacon/statsv | plain | 842 B | 0 b |
Transfer size212.8 KB
Content size776.2 KB
Requests10
| Content | Header Size | Transfer Size | Content Size | Requests |
|---|---|---|---|---|
| html | 0 b | 1.9 KB | 2.2 KB | 1 |
| css | 0 b | 23.8 KB | 218.3 KB | 1 |
| javascript | 0 b | 169.5 KB | 524.2 KB | 1 |
| favicon | 0 b | 6.5 KB | 14.7 KB | 1 |
| json | 0 b | 2.9 KB | 7.4 KB | 1 |
| plain | 0 b | 842 B | 0 b | 1 |
| svg | 0 b | 7.2 KB | 9.4 KB | 4 |
| Total | 0 b | 212.8 KB | 776.2 KB | 10 |
| Domain | Total download time | Transfer Size | Content Size | Requests |
|---|---|---|---|---|
| query.wikidata.org | 2.004 s | 211.9 KB | 776.2 KB | 9 |
| www.wikidata.org | 184 ms | 842 B | 0 b | 1 |
| type | min | median | max |
|---|---|---|---|
| Expires | 0 seconds | 1 hour | 1 hour |
| Last modified | 16 hours | 1 year | 1 year |
Includes requests done after load event end.
| Content | Transfer Size | Requests |
|---|---|---|
| html | 0 b | 0 |
| css | 0 b | 0 |
| javascript | 0 b | 0 |
| image | 0 b | 0 |
| font | 0 b | 0 |
| favicon | 6.5 KB | 1 |
| json | 2.9 KB | 1 |
| plain | 842 B | 1 |
| svg | 7.2 KB | 4 |
| Total | 17.5 KB | 7 |
Includes requests done after DOM content loaded.
| Content | Transfer Size | Requests |
|---|---|---|
| html | 0 b | 0 |
| css | 0 b | 0 |
| javascript | 0 b | 0 |
| image | 0 b | 0 |
| font | 0 b | 0 |
| favicon | 6.5 KB | 1 |
| json | 2.9 KB | 1 |
| plain | 842 B | 1 |
| svg | 7.2 KB | 4 |
| Total | 17.5 KB | 7 |
Tasks ≥ 50 ms blocking the main thread, collected via the Long Task API.
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.
| Script | Frames | Time running | Blocking (share by run time) | Forced style & layout | Triggered by |
|---|---|---|---|---|---|
| index.97f88779.js | 1 | 140.7 ms | 92.2 ms | 47.8 ms | promise callback |
A frame's blocking time is split between its scripts by their share of the frame's work, capped at each script's own run time — blocking from work no script owns (HTML parsing, browser internals) stays unattributed. The per-script blocking view below uses the same attribution.
1 more long frame carried no blocking time (nothing ran past the 50 ms threshold) — long, but harmless to INP and TBT.
How much each script blocked the main thread, derived from the Long Animation Frame API. Each frame's blocking time is split between its scripts by their share of the frame's work, capped at each script's own run time — blocking from work no script owns (HTML parsing, browser internals) is not attributed (older data credits the script that started the frame). The closest answer to "which script should I fix to improve TBT" the platform exposes.
Total Blocking Time attributed per script from the Chrome trace: every main-thread task longer than 50 ms blocks input for the remainder, and each blocking task is credited to the script whose own code ran the longest during that task.
All main-thread work during the full page load, not just the share that blocked input. Calculated from the Chrome trace.
parseHTMLstyleLayoutscriptParseCompilescriptEvaluationpaintCompositeRendergarbageCollectionotherThe 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.
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.
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.
Main-thread CPU time from the Chrome trace split by domain. First party is wikidata.org.
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.
border-bottom-color2×border-left-color2×border-right-color2×border-top-color2×color2×box-shadow1×Want to dig deeper? Download the Chrome trace and drag-and-drop it into Performance in DevTools.