https://xelta.ai/blogs/ai-video-generator-from-image
Tested 2026-09-12 20:41:58 using Chrome 150.0.7871.46 (runtime settings)
This page is fast to paint and visually stable, but a little janky to interact with, loose on best practices and weak on user privacy.
Visual metrics
Google Web Vitals
The page has 35 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.
The page is using Google Tag Manager, this is a performance risk since non-tech users can add JavaScript to your page.
The page has 9 CPU long tasks with the total of 994 ms. The total blocking time is 467 ms and 2 long tasks before first contentful paint with total time of 177 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.
Timings summary
| Metric | Min | Median | Mean | Max |
|---|---|---|---|---|
| First visual change | 900 ms | 900 ms | 900 ms | 900 ms |
| Last visual change | 9.500 s | 9.500 s | 9.500 s | 9.500 s |
| Speed index | 4.027 s | 4.027 s | 4.027 s | 4.027 s |
| Visual readiness | 8.600 s | 8.600 s | 8.600 s | 8.600 s |
| Visual complete 85 | 9.500 s | 9.500 s | 9.500 s | 9.500 s |
| Visual complete 95 | 9.500 s | 9.500 s | 9.500 s | 9.500 s |
| Visual complete 99 | 9.500 s | 9.500 s | 9.500 s | 9.500 s |
Run 1 SpeedIndex median
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.
Rendering was not meaningfully delayed. First paint landed at 748 ms on a 21 ms first byte. The largest paint followed at 1.292 s.
Want to see how much CSS style-recalculation work delayed FCP and LCP, plus CPU long tasks? Run with --cpu.
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 dashed line is FCP, the clock ends at LCP); the gap after the bars is style and layout work. Web fonts are context, not blockers: text renders invisible or in a fallback face while they load, so a font finishing after a paint is the classic reason text changed late.
| Request | When it loaded | Transfer | Download |
|---|---|---|---|
document | 876 ms | 112.8 KB | 875 ms |
0ekytsk9f6hb3.jspotentially blocking | 183 ms | 71.6 KB | 183 ms |
3sy5ezjqwbusz.jspotentially blocking | 181 ms | 48.7 KB | 181 ms |
1ghsza2wgj0ob.jspotentially blocking | 175 ms | 43.9 KB | 175 ms |
27oudxm4bvql9.jspotentially blocking | 171 ms | 42.7 KB | 171 ms |
0v173z2r0p3af.jspotentially blocking | 165 ms | 23.9 KB | 165 ms |
2qwl8sgb3v89v.jspotentially blocking | 163 ms | 19.7 KB | 163 ms |
38cqstpd1yycs.jspotentially blocking | 161 ms | 46.9 KB | 161 ms |
2-hw2eau24v3e.jspotentially blocking | 160 ms | 12.6 KB | 160 ms |
| 19 more requests | all done by 997 ms | 197.9 KB | |
loaded after LCP, at 1.346 s | 65.5 KB | 28 ms | |
loaded after LCP, at 1.347 s | 8.8 KB | 37 ms | |
loaded after LCP, at 1.348 s | 8.8 KB | 19 ms | |
0323 ms969 msFCP 748 msLCP 1.292 s |
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.
avoidScalingImagesThe page has 35 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.
googleTagManagerThe page is using Google Tag Manager, this is a performance risk since non-tech users can add JavaScript to your page.
Google Tag Manager makes it possible for non tech users to add scripts to your page that will downgrade performance.
longTasksThe page has 9 CPU long tasks with the total of 994 ms. The total blocking time is 467 ms and 2 long tasks before first contentful paint with total time of 177 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.
cacheHeadersThe page has 13 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 110.8 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.
javascriptSizeThe total JavaScript transfer size is 1.2 MB and the uncompressed size is 3.7 MB. This is totally crazy! There is really room for improvement here.
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?
cssSizeThe total CSS transfer size is 92 kB and uncompressed size is 687.9 kB. That is big and the CSS could most probably be smaller.
Delivering a massive amount of CSS to the browser is not the best thing you can do, because it means more work for the browser when parsing the CSS against the HTML and that makes the rendering slower. Try to send only the CSS that is used on that page. And make sure to remove CSS rules when they aren't used anymore.
| URL | Transfer | Content |
|---|---|---|
| https://xelta.ai/_next/static/chunks/0_1wdzh4b_yf_.css | 86.2 KB | 641.4 KB |
| https://xelta.ai/_next/static/chunks/0fv-pb_5hofve.css | 3.7 KB | 30.4 KB |
fewFontsThe page has 5 font requests. Do you really need them? What value does the fonts give the user?
How many fonts do you need on a page for the user to get the message? Fonts can slow down the rendering of content, try to avoid loading too many of them because worst case it can make the text invisible until they are loaded (FOIT—flash of invisible text), best case they will flicker the text content when they arrive.
privateAssetsThe 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.
compressAssetsThe page has 2 requests that are served uncompressed. You could save a lot of bytes by sending them compressed instead.
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.
| URL | Transfer | Content |
|---|---|---|
| https://seob.xelta.ai/api/blog/ai-video-generator-from-image | 22.2 KB | 22.0 KB |
| https://seob.xelta.ai/api/blog/published/list?page=1&limit=20 | N/A | 223.6 KB |
responseOkThe page has 2 error responses. The page has 2 responses with code 401.
Your page should never request assets that return a 400 or 500 error. These requests are never cached. If that happens something is broken. Please fix it.
cacheHeadersLongThe page has 19 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.
decodingAsyncThe page has 8 images (out of 67) 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
optimalCssSizehttps://xelta.ai/_next/static/chunks/0_1wdzh4b_yf_.css size is 88.2 kB (88243) and that is bigger than the limit of 25 kB. Try to keep each CSS response under 25 kB.
Render-blocking CSS holds up the first paint until it has fully downloaded, parsed and applied, so smaller CSS files mean a faster start. Split your CSS into a small critical bundle inlined or eagerly loaded, with the rest lazy-loaded.
| URL | Transfer | Content |
|---|---|---|
| https://xelta.ai/_next/static/chunks/0_1wdzh4b_yf_.css | 86.2 KB | 641.4 KB |
modernImageFormatsThe page ships 2 images (out of 34) 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
lazyLoadingImagesThe page has 1 below-the-fold image 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
mimeTypesThe page has 1 misconfigured mime type.
It's not a great idea to let browsers guess content types (content sniffing), in some cases it can actually be a security risk.
unnecessaryHeadersThere are 4 responses that sets both a max-age and expires header. There are 75 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.
pageTitleThe title is too long by 6 characters. The recommended max is 60
Use a title to make the page more relevant to search engines.
thirdPartyThe page do 13% requests to third party domains (11 requests and 579.4 kB). First party is 72 requests and 1.5 MB. The regex .*xelta.* was used to calculate first/third party requests.
Do not load most of your content from third party URLs.
longHeadershttps://connect.face...en_US/fbevents.js has a header content-security-policy that is 1344 characters long. https://connect.face...en_US/fbevents.js has a header permissions-policy that is 874 characters long. https://connect.face.../1123404090023729 has a header content-security-policy that is 1344 characters long. https://connect.face.../1123404090023729 has a header permissions-policy that is 874 characters long.
Do not send response headers that are too long.
gaThe page is using Google Analytics meaning you share your users private information with Google. You should use analytics that care about user privacy, something like https://matomo.org.
Google Analytics share private user information with Google that your user hasn't agreed on sharing.
surveillanceThe page embeds 4 resources from companies that profit from user surveillance. Consider privacy-respecting alternatives.
Embedding scripts or iframes from companies whose business model is surveillance capitalism (Google, Facebook, etc.) leaks detailed user data on every page view, often before the user has had a chance to consent. See https://en.wikipedia.org/wiki/Surveillance_capitalism for background. Prefer privacy-respecting alternatives where possible.
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
thirdPartyPrivacyThe page has 13% requests that are 3rd party (11 requests with a size of 579.4 kB). The page also have request to companies that harvest data from users and do not respect users privacy (see https://en.wikipedia.org/wiki/Surveillance_capitalism). The page do 1 utility request and uses 1 utility tool. The page do 2 tag-manager requests and uses 1 tag-manager tool. The page do 4 survelliance requests and uses 2 survelliance tools. The page do 4 surveillance requests and uses 2 surveillance tools. The page do 2 social requests and uses 1 social tool.
Using third party requests shares user information with that third party. Please avoid that! The project https://github.com/patrickhulce/third-party-web is used to categorize first/third party requests.
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.
Storage and connection
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.
Data collected using Third Party Web version 0.29.2.
Data from run 1
0.0s1.8s3.1s4.4s5.6s6.9s8.2s9.5sWhen the page main content is rendered, collected via the Largest Contentful Paint API. Read more about Largest Contentful Paint.
body > div#app-root > div > div > div:eq(1) > div:eq(0) > div > section:eq(0) > video
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.
The Largest Contentful Paint API matched this image:
How much the page's content shifts as it loads, collected via the Cumulative Layout Shift API.
Sorted by individual shift score (higher = bigger shift). The top entries usually account for most of the page's CLS.
body > div#app-root > header > div > div:eq(2)
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.
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 |
|---|---|---|
cfCacheStatus | 0 ms | DYNAMIC |
cfEdge | 5 ms | – |
cfOrigin | 103 ms | – |
cfExtPri | 0 ms | – |
There are no custom configured scripts.
There are no custom extra metrics from scripting.
How the page is built.
https://xelta.ai/blogs/ai-video-generator-from-image
| Header | Value |
|---|---|
alt-svc | h3=":443"; ma=86400 |
cache-control | private, no-cache, no-store, max-age=0, must-revalidate |
cf-cache-status | DYNAMIC |
cf-ray | a3a1bc7c2cf35a1a-DEL |
content-encoding | br |
content-security-policy-report-only | default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval' https:; style-src 'self' 'unsafe-inline' https:; img-src 'self' data: blob: https:; font-src 'self' data: https:; media-src 'self' data: blob: https:; connect-src 'self' https: wss:; worker-src 'self' blob:; frame-src 'self' https:; object-src 'none'; base-uri 'self'; form-action 'self' https:; frame-ancestors 'self'; |
content-type | text/html; charset=utf-8 |
date | Sat, 12 Sep 2026 20:42:01 GMT |
expect-ct | max-age=86400, enforce |
link | </_next/static/media/83afe278b6a6bb3c-s.p.2bn3s6zvc0dyp.woff2>; rel=preload; as="font"; crossorigin=""; type="font/woff2", </_next/static/chunks/0_1wdzh4b_yf_.css>; rel=preload; as="style", </_next/static/chunks/0fv-pb_5hofve.css>; rel=preload; as="style" |
nel | {"report_to":"cf-nel","success_fraction":0.0,"max_age":604800} |
referrer-policy | same-origin strict-origin-when-cross-origin |
report-to | {"group":"cf-nel","max_age":604800,"endpoints":[{"url":"https://a.nel.cloudflare.com/report/v4?s=CN7WjPg8oIcPfcQfLWTrzcLo2L2wMlVDAKv%2FyU%2F7IlhME34V9lEnFr9rS7dDwTHD%2Bx54b4rweu546kk7dHbhgY9xMdUMMpLICGbuoiOk1hCORGjophX5OSkF"}]} |
server | cloudflare |
server-timing | cfCacheStatus;desc="DYNAMIC" cfEdge;dur=6,cfOrigin;dur=728 |
speculation-rules | "/cdn-cgi/speculation" |
strict-transport-security | max-age=31536000; includeSubDomains; preload |
vary | rsc, next-router-state-tree, next-router-prefetch, next-router-segment-prefetch, Accept-Encoding |
x-content-type-options | nosniff |
x-frame-options | SAMEORIGIN |
x-xss-protection | 1; mode=block |
Transfer size2.0 MB
Content size6.2 MB
Requests81
| Content | Header Size | Transfer Size | Content Size | Requests |
|---|---|---|---|---|
| html | 0 b | 184.8 KB | 1.2 MB | 2 |
| css | 0 b | 89.8 KB | 671.7 KB | 2 |
| javascript | 0 b | 1.1 MB | 3.6 MB | 40 |
| image | 0 b | 428.8 KB | 412.2 KB | 16 |
| font | 0 b | 140.0 KB | 134.9 KB | 5 |
| favicon | 0 b | 9.3 KB | 8.3 KB | 1 |
| other | 0 b | 452 B | 151 B | 4 |
| json | 0 b | 34.7 KB | 268.7 KB | 10 |
| plain | 0 b | 573 B | 0 b | 1 |
| Total | 0 b | 2.0 MB | 6.2 MB | 81 |
| Domain | Total download time | Transfer Size | Content Size | Requests |
|---|---|---|---|---|
| xelta.ai | 8.077 s | 1.2 MB | 4.0 MB | 65 |
| static.cloudflareinsights.com | 96 ms | 10.1 KB | 29.6 KB | 1 |
| vygxif9kfe.execute-api.ap-south-1.amazonaws.com | 321 ms | 6.3 KB | 14.5 KB | 6 |
| cms-b.xelta.ai | 269 ms | 1.6 KB | 69 B | 2 |
| pmt.xelta.ai | 957 ms | 879 B | 1.3 KB | 2 |
| seob.xelta.ai | 1.833 s | 22.2 KB | 245.6 KB | 2 |
| media.xelta.ai | 87 ms | 229.1 KB | 228.2 KB | 1 |
| www.googletagmanager.com | 604 ms | 301.6 KB | 891.6 KB | 2 |
| connect.facebook.net | 117 ms | 247.8 KB | 896.2 KB | 2 |
| type | min | median | max |
|---|---|---|---|
| Expires | 0 seconds | 1 year | 1 year |
| Last modified | 3 hours | 24 hours | 2 weeks |
Includes requests done after load event end.
| Content | Transfer Size | Requests |
|---|---|---|
| html | 72.0 KB | 1 |
| css | 0 b | 0 |
| javascript | 549.4 KB | 4 |
| image | 57.3 KB | 1 |
| font | 0 b | 0 |
| favicon | 9.3 KB | 1 |
| plain | 573 B | 1 |
| Total | 689.7 KB | 9 |
Includes requests done after DOM content loaded.
| Content | Transfer Size | Requests |
|---|---|---|
| html | 72.0 KB | 1 |
| css | 0 b | 0 |
| javascript | 605.8 KB | 11 |
| image | 406.1 KB | 13 |
| font | 91.7 KB | 4 |
| favicon | 9.3 KB | 1 |
| other | 0 b | 3 |
| json | 33.1 KB | 9 |
| plain | 573 B | 1 |
| Total | 1.2 MB | 45 |
--enableProfileRun to see where main-thread time went, blocking time and CPU cost per script, module and function, forced reflows and frame stability. The data is collected in one extra run, so the timing metrics of your measured runs stay untouched.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 |
|---|---|---|---|---|---|
| 11234040900237293rd party | 1 | 184.1 ms | 134.5 ms | 1.6 ms | script tag |
| 0ekytsk9f6hb3.js | 5 | 81.7 ms | 57 ms | – | event handler, script tag |
| fbevents.js3rd party | 1 | 99 ms | 49 ms | – | script tag |
| xelta.ai | 1 | 21.8 ms | 20.8 ms | – | script tag |
| 15o76te91fnaf.js | 1 | 8.3 ms | 3 ms | – | script tag |
| 1ghsza2wgj0ob.js | 1 | 5.8 ms | 2.1 ms | – | script tag |
| 0en-dl3l5-bm2.js | 1 | 12.7 ms | 1.8 ms | – | script tag |
| 3sy5ezjqwbusz.js | 1 | 6.7 ms | 1.7 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.
The browser did not report which script was responsible for this frame — typically its own style/layout work, or a cross-origin script it will not name.
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.
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.
Third party requests categorised by Third party web version 0.29.2.
Requests by category15
Transfer size2.0 MB
Content size6.2 MB
Requests83
Calculated using .*xelta.* (use --firstParty to configure).
| Content | Header Size | Transfer Size | Content Size | Requests |
|---|---|---|---|---|
| html | 0 b | 184.8 KB | 1.2 MB | 2 |
| css | 0 b | 89.8 KB | 671.7 KB | 2 |
| javascript | 0 b | 569.5 KB | 1.8 MB | 35 |
| image | 0 b | 428.8 KB | 412.2 KB | 16 |
| font | 0 b | 140.0 KB | 134.9 KB | 5 |
| favicon | 0 b | 9.3 KB | 8.3 KB | 1 |
| other | 0 b | 452 B | 151 B | 2 |
| json | 0 b | 29.2 KB | 254.2 KB | 7 |
| plain | 0 b | 573 B | 0 b | 1 |
| Total | N/A | 1.4 MB | 4.4 MB | 72 |
| Content | Header Size | Transfer Size | Content Size | Requests |
|---|---|---|---|---|
| html | 0 b | 0 b | 0 b | 0 |
| css | 0 b | 0 b | 0 b | 0 |
| javascript | 0 b | 559.5 KB | 1.8 MB | 5 |
| image | 0 b | 0 b | 0 b | 0 |
| font | 0 b | 0 b | 0 b | 0 |
| favicon | 0 b | 0 b | 0 b | 0 |
| other | 0 b | 0 b | 0 b | 2 |
| json | 0 b | 5.5 KB | 14.4 KB | 3 |
| Total | N/A | 565.8 KB | 1.8 MB | 11 |