https://stf.xelta.ai/blogs/ai-video-generator-free-with-prompt
This page is loose on best practices and weak on user privacy.
The page has 11 font requests. Do you really need them? What value does the fonts give the user?
The total JavaScript transfer size is 450.5 kB and the uncompressed size is 1.4 MB. This is totally crazy! There is really room for improvement here.
The total CSS transfer size is 93.1 kB and uncompressed size is 691.9 kB. That is big and the CSS could most probably be smaller.
Use --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.
Want to see how much CSS style-recalculation work delayed FCP and LCP, plus CPU long tasks? Run with --cpu.
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.
fewFontsThe page has 11 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.
javascriptSizeThe total JavaScript transfer size is 450.5 kB and the uncompressed size is 1.4 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 93.1 kB and uncompressed size is 691.9 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://stf.xelta.ai/_next/static/chunks/2r9v0jpv6hbon.css | 86.4 KB | 639.5 KB |
| https://stf.xelta.ai/_next/static/chunks/0kldb6fnstui0.css | 4.5 KB | 36.2 KB |
longTasksThe page has 1 CPU long task with the total of 55 ms. The total blocking time is 0 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 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 464 B 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.
optimalCssSizehttps://stf.xelta.ai/_next/static/chunks/2r9v0jpv6hbon.css size is 88.5 kB (88474) 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://stf.xelta.ai/_next/static/chunks/2r9v0jpv6hbon.css | 86.4 KB | 639.5 KB |
responseOkThe page has 1 error response. The page has 1 response with code 404.
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 1 request 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.
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.
languageThe page is missing a language definition in the HTML tag. Define it with <html lang="YOUR_LANGUAGE_CODE">
According to the W3C recommendation you should declare the primary language for each Web page with the lang attribute inside the <html> tag https://www.w3.org/International/questions/qa-html-language-declarations#basics.
metaDescriptionThe page is missing a meta description.
Use a page description to make the page more relevant to search engines.
pageTitleThe page is missing a title.
Use a title to make the page more relevant to search engines.
viewportThe page is missing a viewport meta tag. Add <meta name="viewport" content="width=device-width, initial-scale=1"> so the browser lays the page out at the device width.
The viewport meta tag tells the browser how to lay out the page on small screens. Without it (or without width=device-width) the page is rendered at a desktop fallback width and scaled down, which makes text unreadable on mobile. Disabling zoom (user-scalable=no, maximum-scale<=1) is also an accessibility regression. https://developer.mozilla.org/en-US/docs/Web/HTML/Viewport_meta_tag
unnecessaryHeadersThere are 43 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://stf.xelta.ai...-free-with-prompt has a header link that is 1927 characters long. https://stf.xelta.ai...0h245ktd4x0.woff2 has a header content-security-policy-report-only that is 799 characters long. https://stf.xelta.ai...0h245ktd4x0.woff2 has a header report-to that is 623 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
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
thirdPartyPrivacyThe page has 2% requests that are 3rd party (1 requests with a size of 10.3 kB). The page do 1 utility request and uses 1 utility 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.
--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.