Page summary

https://stf.xelta.ai/models/image_generation/stable-image-ultra-workflow

Tested 2026-09-14 11:33:43 using Chrome 150.0.7871.46 (runtime settings)

SummaryWaterfallMetricsRenderingCoachPageXrayCPUThird party

This page is fast to paint, but janky to interact with, prone to layout shifts, loose on best practices and weak on user privacy.

71 / 100
Coach overall
73 / 100
Performance
74 / 100
Best practice
66 / 100
Privacy

How it loaded →

0 → 6.805 s · median run
Frame at 0 ms
start
Frame at 2700 ms
Largest paint2.700 s
Frame at 3800 ms
3.800 s
Frame at 4800 ms
4.800 s
Frame at 5900 ms
5.900 s
Frame at 6900 ms
Complete6.900 s
1.810 s
First Visual Change
3.551 s
Speed Index
5.129 s
Visual Complete 85%
6.805 s
Last Visual Change
TTFB351 msLCP2.204 sTBT1.087 sCLS0.41

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.

Avoid CPU Long Tasks

0 / 100

The page has 15 CPU long tasks with the total of 2.272 s. The total blocking time is 1.087 s and 2 long tasks before first contentful paint with total time of 535 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.

Avoid extra requests by setting cache headers

0 / 100

The page has 11 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 20.8 kB the next access.

Google Web Vitals

min · median · mean · max of 1 run
MetricMinMedianMeanMax
Time To First Byte (TTFB)351 ms351 ms351 ms351 ms
Largest Contentful Paint (LCP)2.204 s2.204 s2.204 s2.204 s
Cumulative Layout Shift (CLS)0.40670.40670.40670.4067

Visual Metrics

min · median · mean · max of 1 run
MetricMinMedianMeanMax
First visual change1.810 s1.810 s1.810 s1.810 s
Last visual change6.805 s6.805 s6.805 s6.805 s
Speed index3.551 s3.551 s3.551 s3.551 s
Visual readiness4.995 s4.995 s4.995 s4.995 s
Visual complete 855.129 s5.129 s5.129 s5.129 s
Visual complete 955.296 s5.296 s5.296 s5.296 s
Visual complete 995.631 s5.631 s5.631 s5.631 s

CPU

min · median · mean · max of 1 run
MetricMinMedianMeanMax
Total Blocking Time1.087 s1.087 s1.087 s1.087 s
Max Potential FID390 ms390 ms390 ms390 ms
CPU long tasks 15151515
CPU last long task happens at6.560 s6.560 s6.560 s6.560 s

More metrics

min · median · mean · max of 1 run
MetricMinMedianMeanMax
First paint2.204 s2.204 s2.204 s2.204 s
Load event end2.422 s2.422 s2.422 s2.422 s

Waterfall

Run 1 SpeedIndex median

First paintFCPLCPDOMContentLoadedDOM interactiveLoadRender-blockingRedirectError

Rendering

Run 1 · median
0.000 s
0s2s4s6s

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

53 frames

Use --filmstrip.showAll to show all filmstrips.

Frame at 0 ms
0 ms
0 %
Frame at 1.700 s
1.700 s
0 %
Frame at 1.900 s
1.900 s
25 %
Frame at 2.000 s
2.000 s
25 %
Frame at 2.100 s
2.100 s
25 %
Frame at 2.200 s
2.200 s
25 %
Frame at 2.300 s
2.300 s
31 %
Frame at 2.400 s
2.400 s
31 %
Frame at 2.500 s
2.500 s
31 %
Frame at 2.600 s
2.600 s
31 %
Frame at 2.700 s
2.700 s
31 %
Frame at 2.800 s
2.800 s
31 %
Frame at 2.900 s
2.900 s
31 %
Frame at 3.000 s
3.000 s
31 %
Frame at 3.100 s
3.100 s
31 %
Frame at 3.200 s
3.200 s
31 %
Frame at 3.300 s
3.300 s
31 %
Frame at 3.400 s
3.400 s
34 %
Frame at 3.500 s
3.500 s
44 %
Frame at 3.600 s
3.600 s
48 %
Frame at 3.700 s
3.700 s
67 %
Frame at 3.800 s
3.800 s
70 %
Frame at 3.900 s
3.900 s
70 %
Frame at 4.000 s
4.000 s
70 %
Frame at 4.100 s
4.100 s
70 %
Frame at 4.200 s
4.200 s
70 %
Frame at 4.300 s
4.300 s
70 %
Frame at 4.400 s
4.400 s
70 %
Frame at 4.500 s
4.500 s
70 %
Frame at 4.600 s
4.600 s
70 %
Frame at 4.700 s
4.700 s
70 %
Frame at 4.800 s
4.800 s
70 %
Frame at 4.900 s
4.900 s
72 %
Frame at 5.000 s
5.000 s
72 %
Frame at 5.100 s
5.100 s
83 %
Frame at 5.200 s
5.200 s
91 %
Frame at 5.300 s
5.300 s
95 %
Frame at 5.400 s
5.400 s
96 %
Frame at 5.500 s
5.500 s
97 %
Frame at 5.600 s
5.600 s
98 %
Frame at 5.700 s
5.700 s
99 %
Frame at 5.800 s
5.800 s
99 %
Frame at 5.900 s
5.900 s
99 %
Frame at 6.000 s
6.000 s
99 %
Frame at 6.100 s
6.100 s
99 %
Frame at 6.200 s
6.200 s
99 %
Frame at 6.300 s
6.300 s
99 %
Frame at 6.400 s
6.400 s
99 %
Frame at 6.500 s
6.500 s
99 %
Frame at 6.600 s
6.600 s
99 %
Frame at 6.700 s
6.700 s
99 %
Frame at 6.800 s
6.800 s
99 %
Frame at 6.900 s
6.900 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?

First paint took 2.204 s. First paint landed at 2.204 s on a 351 ms first byte.

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

Render blocking requests

33 requests · 557.3 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 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 351 ms
92 ms
742 B90 ms
40eix43y6r6kv.jspotentially blocking
javascript · stf.xelta.ai
1.201 s
60.6 KB1.201 s
3dlul65aa-nvq.jspotentially blocking
javascript · stf.xelta.ai
1.182 s
73.3 KB1.182 s
28l2j31ow31z4.jspotentially blocking
javascript · stf.xelta.ai
1.181 s
17.9 KB1.181 s
3sy5ezjqwbusz.jspotentially blocking
javascript · stf.xelta.ai
1.180 s
48.8 KB1.180 s
1ghsza2wgj0ob.jspotentially blocking
javascript · stf.xelta.ai
1.155 s
43.9 KB1.155 s
26--kr-ciax9i.jspotentially blocking
javascript · stf.xelta.ai
1.144 s
42.8 KB1.144 s
36h4r9duhyjke.jspotentially blocking
javascript · stf.xelta.ai
1.104 s
11.1 KB1.104 s
3scmkth2l2ag2.jspotentially blocking
javascript · stf.xelta.ai
1.102 s
15.3 KB1.102 s
25 more requests
all done by 1.493 s
243.6 KB
web font · stf.xelta.ai
1.246 s
65.6 KB1.246 s
web font · stf.xelta.ai
1.228 s
48.4 KB1.228 s
web font · stf.xelta.ai
1.239 s
37.7 KB1.239 s
0551 ms1.102 sFCP · LCP 2.204 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.

What to fix first

Performance advice

73
2 errors10 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.

warn(0)Avoid CPU Long TaskslongTasks

The page has 15 CPU long tasks with the total of 2.272 s. The total blocking time is 1.087 s and 2 long tasks before first contentful paint with total time of 535 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
  • unknown
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
  • self
warn(0)Avoid extra requests by setting cache headerscacheHeaders

The page has 11 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 20.8 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.

Offenders
warn(0)Avoid redirecting the main documentdocumentRedirect

The main document gets redirected 1 time(s). Remove those redirect and make the page faster!

You should never ever redirect the main document, because it will make the page load slower for the user. Well, you should redirect the user if the user tries to use HTTP and there's an HTTPS version of the page. The coach checks for that. :)

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

The total JavaScript transfer size is 1.5 MB and the uncompressed size is 4.7 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?

Offenders
URLTransferContent
https://static.cloudflareinsights.com/beacon.min.js/v31edd6df95cf4e85bb4c19e7a9bdbcba178836298749510.1 KB29.6 KB
https://stf.xelta.ai/_next/static/chunks/0_cis5bf89bk3.js3.7 KB9.3 KB
https://stf.xelta.ai/_next/static/chunks/3ur639cpt-7ui.js11.3 KB38.9 KB
https://stf.xelta.ai/_next/static/chunks/3dlul65aa-nvq.js73.3 KB232.0 KB
https://stf.xelta.ai/_next/static/chunks/3sy5ezjqwbusz.js48.8 KB171.2 KB
https://stf.xelta.ai/_next/static/chunks/turbopack-24c8re3t_hr9w.js6.6 KB18.4 KB
https://stf.xelta.ai/_next/static/chunks/0inxmj29ffnqy.js6.4 KB20.3 KB
https://stf.xelta.ai/_next/static/chunks/17d1-bwqhg7yp.js9.7 KB27.2 KB
https://stf.xelta.ai/_next/static/chunks/1umv1owun4cfl.js8.6 KB33.7 KB
https://stf.xelta.ai/_next/static/chunks/2uoulaw6kucli.js10.1 KB26.2 KB
https://stf.xelta.ai/_next/static/chunks/36h4r9duhyjke.js11.1 KB37.2 KB
https://stf.xelta.ai/_next/static/chunks/2f2i__v854m6r.js9.2 KB30.0 KB
https://stf.xelta.ai/_next/static/chunks/1ytwdotu3mdq4.js10.3 KB27.8 KB
https://stf.xelta.ai/_next/static/chunks/00up96pc24a4e.js10.4 KB25.8 KB
https://stf.xelta.ai/_next/static/chunks/1vr-_-ai-9wxy.js8.0 KB21.0 KB
https://stf.xelta.ai/_next/static/chunks/2rlqhawoa2-1z.js24.1 KB77.8 KB
https://stf.xelta.ai/_next/static/chunks/0qj250lktf-9_.js12.8 KB34.0 KB
https://stf.xelta.ai/_next/static/chunks/1ghsza2wgj0ob.js43.9 KB140.5 KB
https://stf.xelta.ai/_next/static/chunks/0v-y_275lo0v3.js10.8 KB29.1 KB
https://stf.xelta.ai/_next/static/chunks/2qwl8sgb3v89v.js19.7 KB62.0 KB
https://stf.xelta.ai/_next/static/chunks/1j2emy2xhevk5.js6.7 KB15.0 KB
https://stf.xelta.ai/_next/static/chunks/3scmkth2l2ag2.js15.3 KB43.9 KB
https://stf.xelta.ai/_next/static/chunks/08f3iux3oyyat.js12.5 KB34.1 KB
https://stf.xelta.ai/_next/static/chunks/26--kr-ciax9i.js42.8 KB141.9 KB
https://stf.xelta.ai/_next/static/chunks/28l2j31ow31z4.js17.9 KB49.0 KB
https://stf.xelta.ai/_next/static/chunks/1-6-gn7qxfcc_.js1.4 KB599 B
https://stf.xelta.ai/_next/static/chunks/0rd6pxsill_b7.js10.3 KB38.0 KB
https://stf.xelta.ai/_next/static/chunks/0jw_jd7qh-qo-.js10.2 KB32.4 KB
https://stf.xelta.ai/_next/static/chunks/40eix43y6r6kv.js60.6 KB252.0 KB
https://stf.xelta.ai/_next/static/chunks/26pmgklp-z136.js16.1 KB51.4 KB
https://stf.xelta.ai/_next/static/chunks/2s59sncby2703.js12.2 KB33.6 KB
https://stf.xelta.ai/_next/static/chunks/0qyja2b6pvkmf.js9.9 KB28.2 KB
https://stf.xelta.ai/_next/static/chunks/21qxs2_9klwty.js1.8 KB1.4 KB
https://stf.xelta.ai/_next/static/chunks/1yoy6xy7rnaz0.js2.1 KB2.2 KB
https://stf.xelta.ai/_next/static/chunks/0r_-zfn80zo41.js2.3 KB2.7 KB
https://stf.xelta.ai/_next/static/chunks/0ga4rs1yp22vv.js2.4 KB3.0 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://stf.xelta.ai/_next/static/chunks/2rj0wr09m-i2v.js6.2 KB13.9 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/3f1tw02kuplod.js3.3 KB6.2 KB
https://stf.xelta.ai/_next/static/chunks/2k5vpzc_p9jpq.js35.3 KB106.7 KB
https://stf.xelta.ai/_next/static/chunks/3aea5tta4zd_f.js1.2 KB151 B
https://www.googletagmanager.com/gtag/js?id=G-CPG3NLBKHP&cx=c&gtm=4e6992186.6 KB567.5 KB
https://connect.facebook.net/signals/config/1123404090023729.../1123404090023729137.1 KB485.1 KB
https://stf.xelta.ai/_next/static/chunks/3m9-oomc-qdle.js1.4 KB455 B
https://stf.xelta.ai/_next/static/chunks/34zqwff648hvy.js10.7 KB33.9 KB
https://stf.xelta.ai/_next/static/chunks/0_ierrc7whc8i.js10.5 KB31.3 KB
https://stf.xelta.ai/_next/static/chunks/3dh4veiardltk.js47.0 KB206.7 KB
error(50)Have a fast first contentful paintfirstContentfulPaint

First contentful paint can be improved (2.204 s). It is in the Google Web Vitals needs improvement range, slower than 1.8 seconds.

The First Contentful Paint (FCP) metric measures the time from when the page starts loading to when any part of the page content is rendered on the screen. For this metric, "content" refers to text, images (including background images), <svg> elements, or non-white <canvas> elements.

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

The total CSS transfer size is 94 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.

Offenders
URLTransferContent
https://stf.xelta.ai/_next/static/chunks/2r9v0jpv6hbon.css87.1 KB639.5 KB
https://stf.xelta.ai/_next/static/chunks/0kldb6fnstui0.css4.7 KB36.2 KB
warn(60)Don't use private headers on static contentprivateAssets

The page has 4 requests with private headers. 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
infoLong cache headers is goodcacheHeadersLong

The page has 29 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
warn(90)Don't scale images in the browseravoidScalingImages

The page has 1 image 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.

Offenders
warn(90)Always compress text contentcompressAssets

The page has 1 request 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.

Offenders
URLTransferContent
https://stf.xelta.ai/models/image-generation/stable-image-ultra-workflow29.2 KB213.7 KB
infoMake each CSS response smalloptimalCssSize

https://stf.xelta.ai/_next/static/chunks/2r9v0jpv6hbon.css size is 89.2 kB (89166) 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/2r9v0jpv6hbon.css87.1 KB639.5 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(99)Avoid using incorrect mime typesmimeTypes

The 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.

Offenders

Best practice advice

74
1 error1 warning3 info
error(0)Cumulative Layout ShiftcumulativeLayoutShift

You have a poor cumulative layout shift score (0.4067). It is in the Google Web Vitals poor range, with a shift higher than 0.25. You should manually check the filmstrip or video and check if it will affect the user.

Cumulative Layout Shift measures the sum total of all individual layout shift scores for unexpected layout shift that occur. The metric is measuring visual stability by quantify how often users experience unexpected layout shifts. It is one of Google Web Vitals.

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 112 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
warn(50)Avoid too many third party requeststhirdParty

The page do 11% requests to third party domains (12 requests and 764.9 kB). First party is 102 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.

infoDo not send too long headerslongHeaders

https://stf.xelta.ai/manifest.json has a header content-security-policy-report-only that is 799 characters long. https://stf.xelta.ai/manifest.json has a header report-to that is 623 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 621 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...nt/public/pricing has 34 headers.https://stf.xelta.ai...ge-ultra-workflow has 31 headers.https://stf.xelta.ai...nts/active-banner has 34 headers.https://stf.xelta.ai...cms/announcements has 34 headers.https://stf.xelta.ai/api/cms/maintenance has 34 headers.https://stf.xelta.ai/api/geo has 32 headers.

Avoid send too many response headers.

Offenders

Privacy advice

66
6 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
warn(0)Use a strict Content-Security-Policy header to mitigate cross-site scripting (XSS) attacks.contentSecurityPolicyHeader

Set 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

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
warn(0)Set a Permissions-Policy header to control which browser features the page can use.permissionsPolicyHeader

Set 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

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

The page has 8% requests that are 3rd party (9 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 8 survelliance requests and uses 5 survelliance tools. The page do 8 surveillance requests and uses 5 surveillance tools. The page do 2 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

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.

TitleStable Image Ultra - AI ModelThe document title, shown in the browser tab and used by search results.
Layout viewport1350 × 3349 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 elements2,101Very large, slows layout and styleTotal HTML elements. Fewer means less for the browser to style, lay out and paint.
Avg DOM depth11How deeply elements are nested on average.
Max DOM depth19The 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 storage360 BData the page saved in localStorage, kept across visits.
Session storage188 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

7 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 Index3.55 show quickly the page looked done
First Visual Change1.81 sfirst paint reaches the screen
Last Visual Change6.80 sscreen stops changing · 5.00 s after first
nothing painted yet
≥99%
First Visual Change1.81 s
Visual Complete 85%5.13 s
Visual Complete 95%5.30 s
Visual Complete 99%5.63 s
Last Visual Change6.80 s
Visual Readiness5.00 s· first to last change
02.0 s4.0 s6.0 s
Content milestones
Perception index
Visual progress
Visual progress at 0 s0.0s
Visual progress at 2.4 s2.4s
Visual progress at 3.2 s3.2s
Visual progress at 3.9 s3.9s
Visual progress at 4.7 s4.7s
Visual progress at 5.4 s5.4s
Visual progress at 6.2 s6.2s
Visual progress at 6.9 s6.9s
FCP2.20s
LCP2.20s
VC855.13s
Long tasks
0.0s1.4s2.8s4.1s5.5s6.9s

Google Web Vitals

from run 1
351 msTTFB
Good
2.204 sFCP
Needs improvement
1.087 sTBT
Poor

Largest Contentful Paint

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

2.204 sLCP render time

Phase breakdown

  • TTFB351 ms
  • Resource load delay0 ms
  • Resource load duration0 ms
  • Element render delay1.853 s

Element

Element type
<div>
Size (w × h)
107300
Load time
0 ms

DOM path

body > div#app-root > footer > div > div:eq(0)
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.

Cumulative Layout Shift

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

0.407cumulative 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.

  • #10.407<footer class="relative w-full bg-[#090909] text-white overflow-hidden font-sans lg:mt-4"></footer>
    body > div#app-root > footer
  • #20.000<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 msMISS
cfEdge43 ms–
cfOrigin175 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 requests114
Total domains9
Transfer size2.2 MB
Content size6.0 MB
Missing compression1
Cookies70 third-party

Main document

status 200 · 1 redirect

https://stf.xelta.ai/models/image-generation/stable-image-ultra-workflow

HeaderValue
alt-svch3=":443"; ma=86400
cf-cache-statusBYPASS
cf-raya3af141dd8d9a7ec-DEL
dateMon, 14 Sep 2026 11:33:45 GMT
expect-ctmax-age=86400, enforce
location/models/image-generation/stable-image-ultra-workflow
nel{"report_to":"cf-nel","success_fraction":0.0,"max_age":604800}
referrer-policysame-origin strict-origin-when-cross-origin
refresh0;url=/models/image-generation/stable-image-ultra-workflow
report-to{"group":"cf-nel","max_age":604800,"endpoints":[{"url":"https://a.nel.cloudflare.com/report/v4?s=GvrGzMjw4uZt33guPt%2FIo0CCCx4UtcmNa5lerCcPCsFpA2NjiCKioPVLD8UsIM3OhtndA0d4aZh6haRacXLncEqP8SuF%2BEyeuyXErTi29XM5pUhOxgaHJN%2FeYt60AQ%3D%3D"}]}
servercloudflare
server-timingcfCacheStatus;desc="BYPASS" cfEdge;dur=40,cfOrigin;dur=7
speculation-rules"/cdn-cgi/speculation"
strict-transport-securitymax-age=31536000; includeSubDomains; preload
varyaccept-encoding
x-content-type-optionsnosniff
x-frame-optionsSAMEORIGIN
x-xss-protection1; mode=block

Response codes

200
10894.7%
202
10.9%
204
43.5%
308
10.9%

Largest assets on the page (by transfer size)

Top 20 of 114

Requests and sizes per content type

9 types

Transfer size2.2 MB

  • javascript65.3%
  • font14.3%
  • image13.4%
  • css4.2%
  • html1.3%
  • json0.95%
  • favicon0.44%
  • plain0.06%
  • other0.03%

Content size6.0 MB

  • javascript75.7%
  • css11.1%
  • font5.0%
  • image4.3%
  • html3.5%
  • json0.32%
  • favicon0.14%
  • other0.00%
  • plain0.00%

Requests113

  • javascript45.1%
  • image27.4%
  • font9.7%
  • json8.8%
  • plain4.4%
  • css1.8%
  • html0.88%
  • favicon0.88%
  • other0.88%
ContentHeader SizeTransfer SizeContent SizeRequests
html0 b29.2 KB213.7 KB1
css0 b91.8 KB675.7 KB2
javascript0 b1.4 MB4.5 MB51
image0 b296.3 KB261.4 KB31
font0 b315.8 KB304.1 KB11
favicon0 b9.6 KB8.3 KB1
other0 b732 B151 B1
json0 b21.1 KB19.6 KB10
plain0 b1.4 KB2 B5
Total0 b2.2 MB6.0 MB113

Data per domain

9 domains
DomainTotal download timeTransfer SizeContent SizeRequests
stf.xelta.ai69.014 s1.4 MB3.6 MB102
static.cloudflareinsights.com278 ms10.1 KB29.6 KB1
www.googletagmanager.com2.900 s488.2 KB1.4 MB3
connect.facebook.net1.449 s247.5 KB895.2 KB2
analytics.google.com1.000 sN/A0 b1
stats.g.doubleclick.net513 ms555 B0 b1
www.google.co.in503 ms408 B42 B1
mpc-prod-27-s6uit34pua-uk.a.run.app421 msN/A0 b1
telemetry.matchbestsoftware.online229 ms286 B2 B2

Expires & last-modified statistics

typeminmedianmax
Expires0 seconds1 year1 year
Last modified20 minutes2 days2 weeks

Requests loaded after onLoad event

49 requests

Includes requests done after load event end.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript870.4 KB16
image153.8 KB18
font0 b0
favicon9.6 KB1
plain1.4 KB5
json18.2 KB9
Total1.0 MB49

Requests loaded after onContentLoad

49 requests

Includes requests done after DOM content loaded.

ContentTransfer SizeRequests
html0 b0
css0 b0
javascript870.4 KB16
image153.8 KB18
font0 b0
favicon9.6 KB1
plain1.4 KB5
json18.2 KB9
Total1.0 MB49

CPU

334 ms of 1000 ms total. Defer it, replace it with a lighter alternative, or move its work off the main thread to recover most of your TBT.
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.

TBT1.087 s
Max potential input delay390 ms
Total long tasks15
Total time2.272 s
Last task at6.560 s
Before first paint535 ms2 tasks
Before FCP535 ms2 tasks
Before LCP535 ms2 tasks
After load1.579 s12 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 frames15showing the 10 with the most blocking time
Blocking time1.289 sacross all long frames — what hurts INP and TBT
Forced style & layout1 msscripts reading layout mid-frame
Blocking before LCP136.3 msdelaying the largest paint — fix these first
Blocking after load996.4 msafter the load event — didn't delay page load
Input waiting1 framea real interaction was delayed (INP)

What to fix first

ScriptFramesTime runningBlocking (share by run time)Forced style & layoutTriggered by
11234040900237293rd party1390.1 ms333.9 ms0.9 msscript tag
js3rd party2268.3 ms167.5 ms–script tag, timer or animation callback
js3rd party1190.2 ms137.8 ms–script tag
fbevents.js3rd party1175.4 ms113.7 ms–script tag
0_cis5bf89bk3.js1157.2 ms107.1 ms–script tag
3f1tw02kuplod.js1114.3 ms57.5 ms–script tag
3dlul65aa-nvq.js2325.6 ms54.7 ms0.1 msevent handler
gtm.js3rd party176.1 ms26.4 ms–script tag
turbopack-24c8re3t_hr9w.js112.4 ms1.4 ms–script tag

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 · 399.8 msat 6.130 s · after load
blocking 341.3 ms
  • Scripts & other work398.8 ms
  • Animation callbacks0.1 ms
  • Style & layout0.9 ms
  • Render0 ms
2 scripts ran during this frame · forced style & layout 0.9 ms
Ran for
5.8 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)
Ran for
390.1 ms
Forced style and layout
0.9 ms
How it started
script tag
Long animation frame #2 · 195.2 msat 5.878 s · after load
blocking 141 ms
  • Scripts & other work194.6 ms
  • Animation callbacks0.2 ms
  • Style & layout0.4 ms
  • Render0 ms
1 script ran during this frame
js3rd party
Ran for
190.2 ms
How it started
script tag
Long animation frame #3 · 1.394 sat 391.9 ms · before LCP
blocking 136.3 ms
  • Scripts & other work1.252 s
  • Animation callbacks0.1 ms
  • Style & layout142.4 ms
  • Render0 ms
1 script ran during this frame
Ran for
12.4 ms
Queued before running
6.2 ms
How it started
script tag
Long animation frame #4 · 197.5 msat 5.634 s · after load
blocking 127.1 ms
  • Scripts & other work196 ms
  • Animation callbacks0 ms
  • Style & layout1.5 ms
  • Render0 ms
1 script ran during this frame
fbevents.js3rd party
Ran for
175.4 ms
How it started
script tag
Long animation frame #5 · 176.2 msat 5.341 s · after load
blocking 122.9 ms
  • Scripts & other work175.1 ms
  • Animation callbacks0.1 ms
  • Style & layout1 ms
  • Render0 ms
1 script ran during this frame
js3rd party
Ran for
171.5 ms
How it started
script tag
Long animation frame #6 · 813.7 msat 2.448 s · after load
input was waitingblocking 122.4 ms
  • Scripts & other work786.6 ms
  • Animation callbacks3.2 ms
  • Style & layout23.9 ms
  • Render0 ms
15 scripts ran during this frame · forced style & layout 0.1 ms
Ran for
21.3 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)
Ran for
10.9 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)
Ran for
8 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)
Ran for
6.1 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)
Ran for
5 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)
Ran for
5.1 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)
Ran for
10.9 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)
Ran for
5.1 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)
Ran for
23.9 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)
Ran for
5 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)
Ran for
77 ms
Forced style and layout
0.1 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)
Ran for
11.2 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)
Ran for
5.5 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)
Ran for
6.5 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)
Ran for
118.3 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 #7 · 164.2 msat 2.244 s · before load
blocking 110.5 ms
  • Scripts & other work162.2 ms
  • Animation callbacks0.3 ms
  • Style & layout1.7 ms
  • Render0 ms
1 script ran during this frame
Ran for
157.2 ms
How it started
script tag
Long animation frame #8 · 132.8 msat 4.599 s · after load
blocking 66 ms
  • Scripts & other work131.1 ms
  • Animation callbacks0.1 ms
  • Style & layout1.6 ms
  • Render0 ms
1 script ran during this frame
Ran for
114.3 ms
How it started
script tag
Long animation frame #9 · 102.2 msat 5.524 s · after load
blocking 48.8 ms
  • Scripts & other work100.2 ms
  • Animation callbacks1.9 ms
  • Style & layout0.1 ms
  • Render0 ms
1 script ran during this frame
js3rd party
Ran for
96.8 ms
Started by
TimerHandler:setTimeout
How it started
timer or animation callback
Long animation frame #10 · 78 msat 4.888 s · after load
blocking 26.9 ms
  • Scripts & other work77.4 ms
  • Animation callbacks0.1 ms
  • Style & layout0.5 ms
  • Render0 ms
1 script ran during this frame
gtm.js3rd party
Ran for
76.1 ms
How it started
script tag

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 requests17
Tools6
Categories6

Categories

6 categories

Requests by category17

  • survelliance8 req · 5 tools47.1%
  • tag-manager3 req · 1 tool17.6%
  • utility2 req · 2 tools11.8%
  • social2 req · 1 tool11.8%
  • analytics1 req · 1 tool5.9%
  • ad1 req · 1 tool5.9%

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 more8 requests · 5 tools
socialFacebook2 requests · 1 tool
analyticsGoogle Analytics1 requests · 1 tool
adGoogle/Doubleclick Ads1 requests · 1 tool

Unmatched third party domains

2 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.

  • mpc-prod-27-s6uit34pua-uk.a.run.app
  • telemetry.matchbestsoftware.online

First party vs third party

102 first · 12 third party

Transfer size2.2 MB

  • First party1.4 MB66.2%
  • Third party747.0 KB33.8%

Content size6.0 MB

  • First party3.6 MB61.0%
  • Third party2.3 MB39.0%

Requests114

  • First party10289.5%
  • Third party1210.5%

First party requests and sizes per content type

102 requests

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

ContentHeader SizeTransfer SizeContent SizeRequests
html0 b29.2 KB213.7 KB1
css0 b91.8 KB675.7 KB2
javascript0 b695.7 KB2.2 MB45
image0 b295.9 KB261.3 KB30
font0 b315.8 KB304.1 KB11
favicon0 b9.6 KB8.3 KB1
other0 b732 B151 B1
json0 b21.1 KB19.6 KB9
plain0 b584 B0 b1
TotalN/A1.4 MB3.6 MB102

Third party requests and sizes per content type

12 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 B4
json0 b0 b0 b1
TotalN/A747.0 KB2.3 MB12