Page summary

https://stf.xelta.ai/models/social_media/youtube-thumbnail-generator-workflow

Tested 2026-09-14 11:40:01 using Chrome 150.0.7871.46 (runtime settings)

SummaryWaterfallMetricsRenderingCoachPageXrayCPUThird party

This page is visually stable, but slow to paint, janky to interact with, loose on best practices and weak on user privacy.

72 / 100
Coach overall
74 / 100
Performance
80 / 100
Best practice
67 / 100
Privacy

How it loaded →

0 → 4.533 s · median run
Frame at 0 ms
start
Frame at 1200 ms
1.200 s
Frame at 2100 ms
2.100 s
Frame at 3000 ms
3.000 s
Frame at 3800 ms
3.800 s
Frame at 4600 ms
Complete4.600 s
600 ms
First Visual Change
3.058 s
Speed Index
4.500 s
Visual Complete 85%
4.533 s
Last Visual Change
TTFB101 msLCP4.520 sTBT881 msCLS0.00

What to act on · top recommendations

Avoid using Google Tag Manager.

0 / 100

The page is using Google Tag Manager, this is a performance risk since non-tech users can add JavaScript to your page.

Have a fast largest contentful paint

0 / 100

Largest contentful paint is poor 4.520 s. It is in the Google Web Vitals poor range, slower than 4 seconds.

Avoid CPU Long Tasks

0 / 100

The page has 12 CPU long tasks with the total of 1.689 s. The total blocking time is 881 ms and 2 long tasks before first contentful paint with total time of 308 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.

Google Web Vitals

min · median · mean · max of 1 run
MetricMinMedianMeanMax
Time To First Byte (TTFB)101 ms101 ms101 ms101 ms
Largest Contentful Paint (LCP)4.520 s4.520 s4.520 s4.520 s
Cumulative Layout Shift (CLS)0000

Visual Metrics

min · median · mean · max of 1 run
MetricMinMedianMeanMax
First visual change600 ms600 ms600 ms600 ms
Last visual change4.533 s4.533 s4.533 s4.533 s
Speed index3.058 s3.058 s3.058 s3.058 s
Visual readiness3.933 s3.933 s3.933 s3.933 s
Visual complete 854.500 s4.500 s4.500 s4.500 s
Visual complete 954.500 s4.500 s4.500 s4.500 s
Visual complete 994.533 s4.533 s4.533 s4.533 s

CPU

min · median · mean · max of 1 run
MetricMinMedianMeanMax
Total Blocking Time881 ms881 ms881 ms881 ms
Max Potential FID343 ms343 ms343 ms343 ms
CPU long tasks 12121212
CPU last long task happens at3.104 s3.104 s3.104 s3.104 s

More metrics

min · median · mean · max of 1 run
MetricMinMedianMeanMax
First paint700 ms700 ms700 ms700 ms
Load event end1.352 s1.352 s1.352 s1.352 s

Waterfall

Run 1 SpeedIndex median

First paintFCPLCPDOMContentLoadedDOM interactiveLoadRender-blockingRedirectError

Rendering

Run 1 · median
0.000 s
0s1s2s3s4s

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 video

Filmstrip

42 frames

Use --filmstrip.showAll to show all filmstrips.

Frame at 0 ms
0 ms
0 %
Frame at 500 ms
500 ms
0 %
Frame at 600 ms
600 ms
21 %
Frame at 700 ms
700 ms
26 %
Frame at 800 ms
800 ms
91 %
Frame at 900 ms
900 ms
37 %
Frame at 1.000 s
1.000 s
32 %
Frame at 1.100 s
1.100 s
28 %
Frame at 1.200 s
1.200 s
30 %
Frame at 1.300 s
1.300 s
29 %
Frame at 1.400 s
1.400 s
25 %
Frame at 1.500 s
1.500 s
24 %
Frame at 1.600 s
1.600 s
24 %
Frame at 1.700 s
1.700 s
24 %
Frame at 1.900 s
1.900 s
24 %
Frame at 2.000 s
2.000 s
21 %
Frame at 2.100 s
2.100 s
24 %
Frame at 2.200 s
2.200 s
27 %
Frame at 2.300 s
2.300 s
28 %
Frame at 2.400 s
2.400 s
31 %
Frame at 2.500 s
2.500 s
95 %
Frame at 2.600 s
2.600 s
94 %
Frame at 2.700 s
2.700 s
94 %
Frame at 2.800 s
2.800 s
94 %
Frame at 2.900 s
2.900 s
34 %
Frame at 3.000 s
3.000 s
33 %
Frame at 3.100 s
3.100 s
30 %
Frame at 3.200 s
3.200 s
30 %
Frame at 3.300 s
3.300 s
29 %
Frame at 3.400 s
3.400 s
25 %
Frame at 3.500 s
3.500 s
25 %
Frame at 3.600 s
3.600 s
24 %
Frame at 3.700 s
3.700 s
24 %
Frame at 3.800 s
3.800 s
24 %
Frame at 3.900 s
3.900 s
24 %
Frame at 4.000 s
4.000 s
25 %
Frame at 4.100 s
4.100 s
29 %
Frame at 4.200 s
4.200 s
29 %
Frame at 4.300 s
4.300 s
31 %
Frame at 4.400 s
4.400 s
33 %
Frame at 4.500 s
4.500 s
98 %
Frame at 4.600 s
4.600 s
100 %

Click a frame to seek the video to that moment. The dot marks frames where the page changed visually.

Why was rendering delayed?

Rendering was not meaningfully delayed. First paint landed at 700 ms on a 101 ms first byte. The largest paint followed at 4.520 s.

Want to see how much CSS style-recalculation work delayed FCP and LCP, plus CPU long tasks? Run with --cpu.

Render blocking requests

32 requests · 423.4 KB

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.

RequestWhen it loadedTransferDownload
document
stf.xelta.ai · TTFB 101 ms
101 ms
29.6 KB100 ms
3sy5ezjqwbusz.jspotentially blocking
javascript · stf.xelta.ai
334 ms
48.1 KB334 ms
3dlul65aa-nvq.jspotentially blocking
javascript · stf.xelta.ai
334 ms
72.7 KB334 ms
2f2i__v854m6r.jspotentially blocking
javascript · stf.xelta.ai
330 ms
8.4 KB330 ms
1wf8v9a5j3yl_.jspotentially blocking
javascript · stf.xelta.ai
329 ms
7.6 KB329 ms
0hr8xag69xxbh.jspotentially blocking
javascript · stf.xelta.ai
328 ms
7.7 KB328 ms
3b1qi14iervjp.jspotentially blocking
javascript · stf.xelta.ai
328 ms
9.6 KB328 ms
00up96pc24a4e.jspotentially blocking
javascript · stf.xelta.ai
317 ms
9.7 KB317 ms
2uoulaw6kucli.jspotentially blocking
javascript · stf.xelta.ai
316 ms
9.5 KB316 ms
24 more requests
all done by 469 ms
250.0 KB
LCP resource
image — downloaded by 4.461 s, rendered at 4.520 s
213 ms
2.1 KB213 ms
web font · stf.xelta.ai
251 ms
8.2 KB251 ms
web font · stf.xelta.ai
250 ms
37.0 KB250 ms
web font · stf.xelta.ai
252 ms
35.5 KB252 ms
01.130 s2.260 s3.390 sFCP 700 msLCP 4.520 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 9.2.1.

Performance advice

74
3 errors8 warnings3 info
warn(0)Avoid using Google Tag Manager.googleTagManager

The 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.

error(0)Have a fast largest contentful paintlargestContentfulPaint

Largest contentful paint is poor 4.520 s. It is in the Google Web Vitals poor range, slower than 4 seconds.

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.

Offenders
warn(0)Avoid CPU Long TaskslongTasks

The page has 12 CPU long tasks with the total of 1.689 s. The total blocking time is 881 ms and 2 long tasks before first contentful paint with total time of 308 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.

Offenders
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
infoAvoid too many fontsfewFonts
warn(0)Total JavaScript size shouldn't be too bigjavascriptSize

The total JavaScript transfer size is 1.4 MB and the uncompressed size is 4.6 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?

Offenders
URLTransferContent
https://static.cloudflareinsights.com/beacon.min.js/v31edd6df95cf4e85bb4c19e7a9bdbcba178836298749510.1 KB29.6 KB
https://stf.xelta.ai/_next/static/chunks/0_cis5bf89bk3.js3.4 KB9.3 KB
https://stf.xelta.ai/_next/static/chunks/3ur639cpt-7ui.js10.7 KB38.9 KB
https://stf.xelta.ai/_next/static/chunks/3dlul65aa-nvq.js72.7 KB232.0 KB
https://stf.xelta.ai/_next/static/chunks/3sy5ezjqwbusz.js48.1 KB171.2 KB
https://stf.xelta.ai/_next/static/chunks/turbopack-24c8re3t_hr9w.js5.8 KB18.4 KB
https://stf.xelta.ai/_next/static/chunks/043c2jn61g8ch.js5.8 KB20.4 KB
https://stf.xelta.ai/_next/static/chunks/17d1-bwqhg7yp.js9.3 KB27.2 KB
https://stf.xelta.ai/_next/static/chunks/1zleqhxssu9oh.js10.3 KB30.1 KB
https://stf.xelta.ai/_next/static/chunks/2uoulaw6kucli.js9.5 KB26.2 KB
https://stf.xelta.ai/_next/static/chunks/00up96pc24a4e.js9.7 KB25.8 KB
https://stf.xelta.ai/_next/static/chunks/0v-y_275lo0v3.js10.1 KB29.1 KB
https://stf.xelta.ai/_next/static/chunks/3b1qi14iervjp.js9.6 KB27.5 KB
https://stf.xelta.ai/_next/static/chunks/0hr8xag69xxbh.js7.7 KB20.9 KB
https://stf.xelta.ai/_next/static/chunks/1wf8v9a5j3yl_.js7.6 KB32.8 KB
https://stf.xelta.ai/_next/static/chunks/2f2i__v854m6r.js8.4 KB30.0 KB
https://stf.xelta.ai/_next/static/chunks/36h4r9duhyjke.js11.1 KB37.2 KB
https://stf.xelta.ai/_next/static/chunks/2qwl8sgb3v89v.js19.8 KB62.0 KB
https://stf.xelta.ai/_next/static/chunks/2dunoo0yt9za-.js12.7 KB33.7 KB
https://stf.xelta.ai/_next/static/chunks/3scmkth2l2ag2.js15.3 KB43.9 KB
https://stf.xelta.ai/_next/static/chunks/1j2emy2xhevk5.js6.7 KB15.0 KB
https://stf.xelta.ai/_next/static/chunks/2_bm7tpe8f5ne.js24.1 KB77.7 KB
https://stf.xelta.ai/_next/static/chunks/2e28r49c7zefw.js18.5 KB51.1 KB
https://stf.xelta.ai/_next/static/chunks/1ghsza2wgj0ob.js44.0 KB140.5 KB
https://stf.xelta.ai/_next/static/chunks/07so5nrchfe88.js10.2 KB32.5 KB
https://stf.xelta.ai/_next/static/chunks/3lj2255jzxgl-.js16.1 KB51.2 KB
https://stf.xelta.ai/_next/static/chunks/0qyja2b6pvkmf.js9.9 KB28.2 KB
https://stf.xelta.ai/_next/static/chunks/0tynzomeo1z-p.js1.6 KB1003 B
https://stf.xelta.ai/_next/static/chunks/11ottfcrb__c6.js1.9 KB1.8 KB
https://stf.xelta.ai/_next/static/chunks/0r_-zfn80zo41.js2.3 KB2.7 KB
https://stf.xelta.ai/_next/static/chunks/16orvb4qnjgm7.js41.8 KB139.5 KB
https://stf.xelta.ai/_next/static/chunks/1r4b-2voe6my2.js2.4 KB2.9 KB
https://stf.xelta.ai/_next/static/chunks/2tldojfjwreij.js10.6 KB36.2 KB
https://stf.xelta.ai/_next/static/chunks/1_sa18c8qfniy.js6.1 KB16.2 KB
https://www.googletagmanager.com/gtm.js?id=GTM-5XNS5NQ2115.0 KB324.1 KB
https://www.googletagmanager.com/gtag/js?id=G-CPG3NLBKHP186.6 KB567.5 KB
https://connect.facebook.net/en_US/fbevents.js110.4 KB410.0 KB
https://stf.xelta.ai/_next/static/chunks/1ki4hltmjvw2d.js77.6 KB253.9 KB
https://stf.xelta.ai/_next/static/chunks/3f1tw02kuplod.js3.3 KB6.2 KB
https://stf.xelta.ai/_next/static/chunks/2k5vpzc_p9jpq.js35.3 KB106.7 KB
https://connect.facebook.net/signals/config/1123404090023729.../1123404090023729137.0 KB485.1 KB
https://www.googletagmanager.com/gtag/js?id=G-CPG3NLBKHP&cx=c&gtm=4e6992186.6 KB567.5 KB
https://stf.xelta.ai/_next/static/chunks/3m9-oomc-qdle.js1.4 KB455 B
https://stf.xelta.ai/_next/static/chunks/0en-dl3l5-bm2.js10.7 KB33.9 KB
https://stf.xelta.ai/_next/static/chunks/3601yvag566gb.js10.4 KB31.2 KB
https://stf.xelta.ai/_next/static/chunks/3dh4veiardltk.js47.0 KB206.7 KB
error(20)Avoid missing and error requestsresponseOk
warn(30)Avoid extra requests by setting cache headerscacheHeaders

The page has 7 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 6.2 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.

Offenders
warn(50)Total CSS size shouldn't be too bigcssSize

The total CSS transfer size is 91.6 kB and uncompressed size is 687.3 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.

Offenders
URLTransferContent
https://stf.xelta.ai/_next/static/chunks/1lgy-fxfy7-hi.css85.4 KB634.9 KB
https://stf.xelta.ai/_next/static/chunks/0kldb6fnstui0.css4.1 KB36.2 KB
warn(60)Don't use private headers on static contentprivateAssets

The page has 5 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.

Offenders
warn(70)Apply the right priority hints to the LCP imagelcpImageHints

The LCP image is missing fetchpriority="high". Adding it tells the browser to fetch the image with high priority instead of the default heuristic (which often deprioritises hero images that are loaded after the HTML has been parsed).

When the Largest Contentful Paint element is an image, the browser priority hints applied to that element directly affect the LCP metric. The image must NOT be loading="lazy" (that defers the fetch until near-viewport, which is the opposite of what an LCP image needs) and SHOULD be fetchpriority="high" (so the browser fetches it with high priority instead of guessing). https://web.dev/articles/fetch-priority

Offenders
  • <img alt="AI Avatar" draggable="false" width="80" height="80" decoding="async" data-nimg="1" class="w-full h-full object-cover pointer-events-none" srcset="/_next/image?url=%2Fchatboard%2Favtar.png&amp;w=96&amp;q=75 1x, /_next/image?url=%2Fchatboard%2Favtar.png&amp;w=256&amp;q=75 2x" src="/_next/image?url=%2Fchatboard%2Favtar.png&amp;w=256&amp;q=75" style="color: transparent;">
infoLong cache headers is goodcacheHeadersLong

The page has 18 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.

Offenders
infoMake each CSS response smalloptimalCssSize

https://stf.xelta.ai/_next/static/chunks/1lgy-fxfy7-hi.css size is 87.4 kB (87436) 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.

Offenders
URLTransferContent
https://stf.xelta.ai/_next/static/chunks/1lgy-fxfy7-hi.css85.4 KB634.9 KB
warn(95)Inline CSS for faster first renderinlineCss

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.

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.

error(97)Avoid using incorrect mime typesmimeTypes

The page has 3 misconfigured mime types.

It's not a great idea to let browsers guess content types (content sniffing), in some cases it can actually be a security risk.

Offenders

Best practice advice

80
2 warnings4 info
infoAvoid unnecessary headersunnecessaryHeaders

There are 1 response that sets a p3p header. There are 5 responses that sets both a max-age and expires header. There are 3 responses that sets a pragma no-cache header (that is a request header). There are 100 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.

Offenders
infoMeta descriptionmetaDescription

The meta description is too long. It has 224 characters, the recommended max is 160

Use a page description to make the page more relevant to search engines.

warn(50)Page titlepageTitle

The title is too long by 21 characters. The recommended max is 60

Use a title to make the page more relevant to search engines.

warn(50)Avoid too many third party requeststhirdParty

The page do 16% requests to third party domains (16 requests and 765.4 kB). First party is 86 requests and 1.3 MB. The regex .*xelta.* was used to calculate first/third party requests.

Do not load most of your content from third party URLs.

infoDo not send too long headerslongHeaders

https://stf.xelta.ai...enerator-workflow has a header link that is 1927 characters long. https://stf.xelta.ai...18_wedhzk4h.woff2 has a header content-security-policy-report-only that is 799 characters long. https://stf.xelta.ai...18_wedhzk4h.woff2 has a header report-to that is 617 characters long. https://stf.xelta.ai...ta.ai/_next/image has a header content-security-policy-report-only that is 799 characters long. https://stf.xelta.ai...ta.ai/_next/image has a header report-to that is 625 characters long. https://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.

Offenders
infoAvoid use too many response headersmanyHeaders

https://stf.xelta.ai/api/geo has 32 headers.https://stb.xelta.ai...nts/active-banner has 34 headers.

Avoid send too many response headers.

Offenders

Privacy advice

67
1 error5 warnings2 info
warn(0)Avoid using Google Analyticsga

The 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.

warn(0)Avoid embedding services from surveillance capitalist companiessurveillance

The page embeds 5 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.

Offenders
infoSet a Cross-Origin-Embedder-Policy header so cross-origin subresources opt in to being embedded.crossOriginEmbedderPolicyHeader

Set 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

Offenders
warn(0)Set a Cross-Origin-Opener-Policy header to isolate the page from cross-origin windows.crossOriginOpenerPolicyHeader

Set 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

Offenders
infoSet a Cross-Origin-Resource-Policy header to limit who may embed the page.crossOriginResourcePolicyHeader

Set 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

Offenders
error(0)Serve all responses on HTTPS (when you are on HTTPS)mixedContent

You need to serve all responses on HTTPS. The page have 2 responses using HTTP. That is a privacy and security risk.

You need to make sure that if you are on HTTPS, all responses are on HTTPS so that the content served are secured.

Offenders
warn(0)Do not share user data with third parties.thirdPartyPrivacy

The page has 10% requests that are 3rd party (10 requests with a size of 764.6 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 2 utility requests and uses 2 utility tools. The page do 3 tag-manager requests and uses 1 tag-manager tool. The page do 9 survelliance requests and uses 5 survelliance tools. The page do 9 surveillance requests and uses 5 surveillance tools. The page do 3 social requests and uses 1 social tool. The page do 1 analytics request and uses 1 analytics tool. The page do 1 ad request and uses 1 ad 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.

Offenders
warn(90)Avoid third party cookies that is used to track the user.thirdPartyCookies

The page sets 1 third party cookie.

Third party cookies are used to track the user. They are automatically blocked in Safari and Firefox.

Offenders
  • .facebook.com

Page info

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.

Page info

Document

What the page says it is and how large it rendered.

TitleYouTube Thumbnail Generator AI | Create Eye-Catching Thumbnails from Text – XeltaThe document title, shown in the browser tab and used by search results.
Layout viewport1350 × 1318 pxThe width the page laid out at, and the full height of the rendered document.

DOM structure

How much markup the browser has to build, style and lay out.

DOM elements1,427Very large, slows layout and styleTotal HTML elements. Fewer means less for the browser to style, lay out and paint.
Avg DOM depth10How deeply elements are nested on average.
Max DOM depth16The deepest nesting on the page. Deep branches cost more style recalculation.
Iframes1Embedded documents. Each is a separate page the browser loads and renders.
Script tags60Number of script elements. More scripts usually means more main-thread work.

Storage and connection

What the page stored on the client, and the network it was tested on.

Local storage725 BData the page saved in localStorage, kept across visits.
Session storage412 BData kept in sessionStorage for this tab session only.
Connection type4GWhat the Network Information API reported for the test connection.

Resource hints

4 hints
dns-prefetch
  • https://media.xelta.ai/
preconnect
  • https://media.xelta.ai/
  • https://fonts.googleapis.com/
  • https://fonts.gstatic.com/

Technologies used to build the page

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.

Detected technologies

6 technologies

Third-party tools

16 tools

Data collected using Third Party Web version 0.29.2.

Utility
  • Cloudflare
  • Other Google APIs/SDKs
Tag-manager
  • Google Tag Manager
Survelliance
  • Google Tag Manager
  • Facebook
  • Google Analytics
  • Google/Doubleclick Ads
  • Other Google APIs/SDKs
Surveillance
  • Google Tag Manager
  • Facebook
  • Google Analytics
  • Google/Doubleclick Ads
  • Other Google APIs/SDKs
Social
  • Facebook
Analytics
  • Google Analytics
Ad
  • Google/Doubleclick Ads

Data from run 1

Visual Metrics

Visual milestones

all times from navigation start
Speed Index3.06 show quickly the page looked done
First Visual Change0.60 sfirst paint reaches the screen
Last Visual Change4.53 sscreen stops changing · 3.93 s after first
0.60 sFirst Visual Change
Visual Complete 85% · Visual Complete 95% · Visual Complete 99% · Last Visual Change4.50 s
Visual Readiness3.93 s· first to last change
01.0 s2.0 s3.0 s4.0 s
Content milestones
Perception index
Visual progress
Visual progress at 0 s0.0s
Visual progress at 1 s1.0s
Visual progress at 1.6 s1.6s
Visual progress at 2.3 s2.3s
Visual progress at 2.8 s2.8s
Visual progress at 3.4 s3.4s
Visual progress at 4 s4.0s
Visual progress at 4.6 s4.6s
FCP0.70s
LCP4.52s
VC854.50s
Long tasks
0.0s0.9s1.8s2.8s3.7s4.6s

Google Web Vitals

from run 1

Largest Contentful Paint

When the page main content is rendered, collected via the Largest Contentful Paint API. Read more about Largest Contentful Paint.

4.520 sLCP render time

Phase breakdown

  • TTFB101 ms
  • Resource load delay4.153 s
  • Resource load duration214 ms
  • Element render delay53 ms

Element

Element type
<img>
Size (w × h)
4512
URL
https://stf.xelta.ai...ta.ai/_next/image
Load time
4.500 s

DOM path

body > div#app-root > button > img
LCP

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:

LCP element

Cumulative Layout Shift

How much the page's content shifts as it loads, collected via the Cumulative Layout Shift API.

0.000cumulative layout shift score

Elements that shifted

Sorted by individual shift score (higher = bigger shift). The top entries usually account for most of the page's CLS.

  • #10.000<div class="hidden lg:flex items-center flex-shrink-0 ml-auto"></div>
    body > div#app-root > header > div > div:eq(2)
Layout shift

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.

Browser Metrics

Navigation Timing
Extra timings

Server timings

Timing data the server chose to expose through Server-Timing response headers on the main document — typically backend time, cache status or experiment flags.

Server timings

3 entries
NameDurationDescription
cfCacheStatus0 msHIT
cfEdge7 ms–
cfOrigin0 ms–

Custom metrics collected through JavaScript

There are no custom configured scripts.

Extra metrics collected using scripting

There are no custom extra metrics from scripting.

PageXray

How the page is built.

HTTP versionHTTP/2.0
Total requests102
Total domains15
Transfer size2.0 MB
Content size5.7 MB
Missing compression0
Cookies31 third-party

Main document

status 200 · 0 redirects

https://stf.xelta.ai/models/social_media/youtube-thumbnail-generator-workflow

HeaderValue
age174222
alt-svch3=":443"; ma=86400
cache-controlprivate, max-age=604800, must-revalidate
cf-cache-statusHIT
cf-raya3af1d5caed109ba-DEL
content-encodingbr
content-security-policydefault-src 'self'; script-src 'self' 'nonce-9dI78Rm7o6OSxtoArCuGTg==' 'strict-dynamic' https:; style-src 'self' 'unsafe-inline' https://fonts.googleapis.com; font-src 'self' https://fonts.gstatic.com data:; img-src 'self' data: blob: https:; media-src 'self' https: blob:; connect-src 'self' https: wss:; frame-src 'self' https:; frame-ancestors 'none'; object-src 'none'; base-uri 'self'; form-action 'self'
content-security-policy-report-onlydefault-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-typetext/html; charset=utf-8
dateMon, 14 Sep 2026 11:40:03 GMT
expect-ctmax-age=86400, enforce
last-modifiedSat, 12 Sep 2026 11:16:21 GMT
link</_next/static/media/47fe1b7cd6e6ed85-s.p.3bh2vc0w-r-ll.woff2>; rel=preload; as="font"; crossorigin=""; nonce="9dI78Rm7o6OSxtoArCuGTg=="; type="font/woff2", </_next/static/media/83afe278b6a6bb3c-s.p.2bn3s6zvc0dyp.woff2>; rel=preload; as="font"; crossorigin=""; nonce="9dI78Rm7o6OSxtoArCuGTg=="; type="font/woff2", </_next/static/media/8dfd6563338cbf38-s.p.2uos8jt9rp249.woff2>; rel=preload; as="font"; crossorigin=""; nonce="9dI78Rm7o6OSxtoArCuGTg=="; type="font/woff2", </_next/static/media/8e6fa89aa22d24ec-s.p.2o7m9ogm38dql.woff2>; rel=preload; as="font"; crossorigin=""; nonce="9dI78Rm7o6OSxtoArCuGTg=="; type="font/woff2", </_next/static/media/9d0c71fa164043fa-s.p.2snziqcncuet5.woff2>; rel=preload; as="font"; crossorigin=""; nonce="9dI78Rm7o6OSxtoArCuGTg=="; type="font/woff2", </_next/static/media/9e9f04e3c37952ab-s.p.0pan85mumqyf3.woff2>; rel=preload; as="font"; crossorigin=""; nonce="9dI78Rm7o6OSxtoArCuGTg=="; type="font/woff2", </_next/static/media/a218039a3287bcfd-s.p.43zbiuwnnoiok.woff2>; rel=preload; as="font"; crossorigin=""; nonce="9dI78Rm7o6OSxtoArCuGTg=="; type="font/woff2", </_next/static/media/c875c6f5d3e977ac-s.p.1h18_wedhzk4h.woff2>; rel=preload; as="font"; crossorigin=""; nonce="9dI78Rm7o6OSxtoArCuGTg=="; type="font/woff2", </_next/static/media/ce62453a442c7f35-s.p.0a0h245ktd4x0.woff2>; rel=preload; as="font"; crossorigin=""; nonce="9dI78Rm7o6OSxtoArCuGTg=="; type="font/woff2", </_next/static/media/e2334d715941921e-s.p.3o_v2fun1jzxk.woff2>; rel=preload; as="font"; crossorigin=""; nonce="9dI78Rm7o6OSxtoArCuGTg=="; type="font/woff2", </_next/static/media/e8f2fbee2754df70-s.p.1dqa_6e_ad4sj.woff2>; rel=preload; as="font"; crossorigin=""; nonce="9dI78Rm7o6OSxtoArCuGTg=="; type="font/woff2", </_next/static/chunks/1lgy-fxfy7-hi.css>; rel=preload; as="style"; nonce="9dI78Rm7o6OSxtoArCuGTg==", </_next/static/chunks/0kldb6fnstui0.css>; rel=preload; as="style"; nonce="9dI78Rm7o6OSxtoArCuGTg=="
nel{"report_to":"cf-nel","success_fraction":0.0,"max_age":604800}
permissions-policycamera=(), microphone=(self), geolocation=(), interest-cohort=()
referrer-policysame-origin strict-origin-when-cross-origin
report-to{"group":"cf-nel","max_age":604800,"endpoints":[{"url":"https://a.nel.cloudflare.com/report/v4?s=O%2FGqAdS9UZsjBxT%2FuVUoQNIjmsfdHd0r3U892nSwXOzNSI3hfb1R7I09HdX4Hl7tT8HUhY4ZS0%2Fh5l7%2F0a5PQjEhYz%2BM3wEwzQUCUOjws8u%2FY6l7fWJkDBxyN%2FbPFg%3D%3D"}]}
servercloudflare
server-timingcfCacheStatus;desc="HIT" cfEdge;dur=7,cfOrigin;dur=0
speculation-rules"/cdn-cgi/speculation"
strict-transport-securitymax-age=31536000; includeSubDomains; preload
varyrsc, next-router-state-tree, next-router-prefetch, next-router-segment-prefetch, Accept-Encoding
x-content-type-optionsnosniff
x-frame-optionsSAMEORIGIN
x-xss-protection1; mode=block

Response codes

200
8886.3%
202
11.0%
204
54.9%
401
22.0%
404
65.9%

Largest assets on the page (by transfer size)

Top 20 of 102

Requests and sizes per content type

9 types

Transfer size2.0 MB

  • javascript70.3%
  • font15.4%
  • image7.5%
  • css4.4%
  • html1.5%
  • favicon0.48%
  • json0.34%
  • plain0.07%
  • other0.03%

Content size5.7 MB

  • javascript77.3%
  • css11.4%
  • font5.2%
  • html3.7%
  • image2.3%
  • favicon0.14%
  • json0.03%
  • other0.00%
  • plain0.00%

Requests94

  • javascript48.9%
  • image17.0%
  • font11.7%
  • json7.4%
  • plain6.4%
  • other4.3%
  • css2.1%
  • html1.1%
  • favicon1.1%
ContentHeader SizeTransfer SizeContent SizeRequests
html0 b29.6 KB214.2 KB1
css0 b89.5 KB671.2 KB2
javascript0 b1.4 MB4.4 MB46
image0 b150.4 KB132.7 KB16
font0 b310.4 KB304.1 KB11
favicon0 b9.6 KB8.3 KB1
other0 b637 B151 B4
json0 b6.8 KB1.6 KB7
plain0 b1.4 KB2 B6
Total0 b2.0 MB5.7 MB94

Data per domain

15 domains
DomainTotal download timeTransfer SizeContent SizeRequests
stf.xelta.ai17.575 s1.2 MB3.4 MB78
static.cloudflareinsights.com158 ms10.1 KB29.6 KB1
devpmt.xelta.ai1.145 s747 B117 B2
stb.xelta.ai1.192 s2.3 KB98 B4
cms-b.stg2.xelta.ai1.618 s1.1 KB69 B2
www.googletagmanager.com1.059 s488.2 KB1.4 MB3
connect.facebook.net293 ms247.5 KB895.2 KB2
us-assets.i.posthog.com1.372 s46 B0 b2
analytics.google.com264 msN/A0 b1
stats.g.doubleclick.net170 ms555 B0 b1
www.google.co.in232 ms408 B42 B1
mpc-prod-27-s6uit34pua-uk.a.run.app357 msN/A0 b1
us.i.posthog.com1.256 s496 B174 B1
telemetry.matchbestsoftware.online161 ms286 B2 B2
www.facebook.com77 msN/A0 b1

Expires & last-modified statistics

typeminmedianmax
Expires0 seconds1 year1 year
Last modified38 minutes2 days2 weeks

Requests loaded after onLoad event

33 requests

Includes requests done after load event end.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript921.4 KB12
image8.5 KB3
font0 b0
favicon9.6 KB1
json4.9 KB6
plain1.4 KB6
other0 b1
Total947.4 KB33

Requests loaded after onContentLoad

39 requests

Includes requests done after DOM content loaded.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript982.4 KB16
image8.5 KB3
font0 b0
favicon9.6 KB1
other0 b3
json4.9 KB6
plain1.4 KB6
Total1008.4 KB39

CPU

Get deeper CPU insight with one extra run
Run with --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.

Long tasks

Tasks ≥ 50 ms blocking the main thread, collected via the Long Task API.

TBT881 ms
Max potential input delay343 ms
Total long tasks12
Total time1.689 s
Last task at3.104 s
Before first paint308 ms2 tasks
Before FCP308 ms2 tasks
Before LCP1.689 s12 tasks
After load1.194 s8 tasks

Long Animation Frames

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.

Long animation frames12showing the 10 with the most blocking time
Blocking time1.136 sacross all long frames — what hurts INP and TBT
Forced style & layout0.1 msscripts reading layout mid-frame
Blocking before LCP1.128 sdelaying the largest paint — fix these first
Blocking after load796.2 msafter the load event — didn't delay page load

What to fix first

ScriptFramesTime runningBlocking (share by run time)Forced style & layoutTriggered by
fbevents.js3rd party1343.6 ms293.6 ms–script tag
11234040900237293rd party1225.3 ms172.3 ms0.1 msscript tag
js3rd party2226.3 ms126.3 ms–script tag, timer or animation callback
3sy5ezjqwbusz.js1170.1 ms105.5 ms–script tag
3dlul65aa-nvq.js1132.7 ms99.3 ms–event handler
gtm.js3rd party1145.4 ms95.5 ms–script tag
1ki4hltmjvw2d.js1108.5 ms56.7 ms–script tag
js3rd party193.9 ms43.6 ms–script tag
v31edd6df95cf4e85bb4c19e7a9bdbcba17883629874953rd party116 ms9.9 ms–module script

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.

Long animation frame #1 · 343.8 msat 1.635 s · before LCP
blocking 293.8 ms
  • Scripts & other work343.8 ms
  • Animation callbacks0 ms
  • Style & layout0 ms
  • Render0 ms
1 script ran during this frame
fbevents.js3rd party
Ran for
343.6 ms
How it started
script tag
Long animation frame #2 · 231.2 msat 2.402 s · before LCP
blocking 176.2 ms
  • Scripts & other work230.4 ms
  • Animation callbacks0.1 ms
  • Style & layout0.7 ms
  • Render0 ms
1 script ran during this frame · forced style & layout 0.1 ms
Ran for
225.3 ms
Forced style and layout
0.1 ms
How it started
script tag
Long animation frame #3 · 197.2 msat 664.2 ms · before LCP
blocking 121.5 ms
  • Scripts & other work195.9 ms
  • Animation callbacks1.2 ms
  • Style & layout0.1 ms
  • Render0 ms
2 scripts ran during this frame
Ran for
16 ms
How it started
module script
Ran for
170.1 ms
How it started
script tag
Long animation frame #4 · 440.2 msat 135.2 ms · before LCP
blocking 109.3 ms
  • Scripts & other work309.2 ms
  • Animation callbacks1.4 ms
  • Style & layout129.6 ms
  • Render0 ms

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.

Long animation frame #5 · 152.6 msat 1.155 s · before LCP
blocking 100.7 ms
  • Scripts & other work134.6 ms
  • Animation callbacks0 ms
  • Style & layout18 ms
  • Render0 ms
1 script ran during this frame
Ran for
132.7 ms
Started by
MessagePort.onmessage
How it started
event handler
Source function
z
Position in source
character 3191 into the file (locate it via DevTools → Performance → the Long Animation Frames track)
Long animation frame #6 · 145.6 msat 2.001 s · before LCP
blocking 95.7 ms
  • Scripts & other work145.6 ms
  • Animation callbacks0 ms
  • Style & layout0 ms
  • Render0 ms
1 script ran during this frame
gtm.js3rd party
Ran for
145.4 ms
How it started
script tag
Long animation frame #7 · 140.7 msat 2.168 s · before LCP
blocking 90.7 ms
  • Scripts & other work140.7 ms
  • Animation callbacks0 ms
  • Style & layout0 ms
  • Render0 ms
1 script ran during this frame
js3rd party
Ran for
140.4 ms
How it started
script tag
Long animation frame #8 · 114.5 msat 1.519 s · before LCP
blocking 59.6 ms
  • Scripts & other work114.1 ms
  • Animation callbacks0.1 ms
  • Style & layout0.3 ms
  • Render0 ms
1 script ran during this frame
Ran for
108.5 ms
How it started
script tag
Long animation frame #9 · 96.1 msat 2.657 s · before LCP
blocking 44.4 ms
  • Scripts & other work95.7 ms
  • Animation callbacks0.3 ms
  • Style & layout0.1 ms
  • Render0 ms
1 script ran during this frame
js3rd party
Ran for
93.9 ms
How it started
script tag
Long animation frame #10 · 85.8 msat 2.312 s · before LCP
blocking 35.8 ms
  • Scripts & other work85.8 ms
  • Animation callbacks0 ms
  • Style & layout0 ms
  • Render0 ms
1 script ran during this frame
js3rd party
Ran for
85.9 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback

Blocking time per script (browser-reported)

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.

Third party

Third party requests categorised by Third party web version 0.29.2.

Third-party requests19
Tools6
Categories6
Third-party cookies1

Categories

6 categories

Requests by category19

  • survelliance9 req · 5 tools47.4%
  • tag-manager3 req · 1 tool15.8%
  • social3 req · 1 tool15.8%
  • utility2 req · 2 tools10.5%
  • analytics1 req · 1 tool5.3%
  • ad1 req · 1 tool5.3%

Third party requests and tools

6 categories
utilityCloudflareOther Google APIs/SDKs2 requests · 2 tools
tag-managerGoogle Tag Manager3 requests · 1 tool
survellianceGoogle Tag ManagerFacebookGoogle Analytics+ 2 more9 requests · 5 tools
socialFacebook3 requests · 1 tool
analyticsGoogle Analytics1 requests · 1 tool
adGoogle/Doubleclick Ads1 requests · 1 tool

Unmatched third party domains

4 domains

Domains that didn't match any tool in Third party web. If you are sure they are third party domains, please do a PR to that project. You can also fine tune the list using --firstParty.

  • us-assets.i.posthog.com
  • mpc-prod-27-s6uit34pua-uk.a.run.app
  • us.i.posthog.com
  • telemetry.matchbestsoftware.online
Third party cookies1
.facebook.com1 cookie

First party vs third party

86 first · 16 third party

Transfer size2.0 MB

  • First party1.2 MB62.9%
  • Third party747.5 KB37.1%

Content size5.7 MB

  • First party3.4 MB59.4%
  • Third party2.3 MB40.6%

Requests102

  • First party8684.3%
  • Third party1615.7%

First party requests and sizes per content type

86 requests

Calculated using .*xelta.* (use --firstParty to configure).

ContentHeader SizeTransfer SizeContent SizeRequests
html0 b29.6 KB214.2 KB1
css0 b89.5 KB671.2 KB2
javascript0 b669.5 KB2.1 MB40
image0 b150.0 KB132.7 KB15
font0 b310.4 KB304.1 KB11
favicon0 b9.6 KB8.3 KB1
other0 b637 B151 B4
json0 b6.8 KB1.6 KB6
plain0 b586 B0 b1
TotalN/A1.2 MB3.4 MB86

Third party requests and sizes per content type

16 requests
ContentHeader SizeTransfer SizeContent SizeRequests
html0 b0 b0 b0
css0 b0 b0 b0
javascript0 b745.8 KB2.3 MB6
image0 b408 B42 B1
font0 b0 b0 b0
favicon0 b0 b0 b0
plain0 b841 B2 B5
json0 b0 b0 b1
TotalN/A747.5 KB2.3 MB16