https://prep.xelta.ai/ai-studio/xelta-prism/playground
Tested 2026-07-31 14:59:53 using Chrome 150.0.7871.186 (runtime settings)
The red band on the timeline marks when the main thread was busy with long tasks: moments when the page could not paint or respond, however the video looks.
Download videoUse --filmstrip.showAll to show all filmstrips.
Click a frame to seek the video to that moment. The dot marks frames where the page changed visually.
The server dominated the wait. The first byte took 921 ms (51 % of the time to First Contentful Paint). Nothing can render before it arrives, and Google Web Vitals considers a TTFB over 800 ms in need of improvement. See the request timing on the Waterfall tab. First paint landed at 1.800 s; the 2 render-blocking requests were done by 1.044 s and the remaining ~756 ms is style, layout and web-font loading.
Want to see how much CSS style-recalculation work delayed FCP and LCP, plus CPU long tasks? Run with --cpu.
Blocking requests delay both paints: the browser renders nothing until they arrive, so they push First Contentful Paint and everything after it, including the largest paint (LCP). Requests that block the parser inside the body stall everything after them in the document. Load JavaScript with defer or async, and keep non-critical CSS off the critical path with media attributes. Bars show when each request loaded on a clock that runs to the last paint; the gap after the bars is style and layout work. Web fonts are context, not blockers: text renders invisible or in a fallback face while they load, so a font finishing after a paint is the classic reason text changed late.
| Request | When it loaded | Transfer | Download |
|---|---|---|---|
document | 1.186 s | 17.6 KB | 1.184 s |
0bn2cukj3v_dz.cssblocking | 96 ms | 73.2 KB | 96 ms |
08ak-dq81l91~.cssblocking | 69 ms | 1.4 KB | 69 ms |
0q0f-q-esowzk.jspotentially blocking | 347 ms | 79.1 KB | 347 ms |
0lvpde6cbyrh4.jspotentially blocking | 312 ms | 3.1 KB | 312 ms |
0wc5chl2qfyvw.jspotentially blocking | 311 ms | 4.6 KB | 311 ms |
110s1oj6k~2eu.jspotentially blocking | 305 ms | 10.0 KB | 305 ms |
0y0ijhqmszjlv.jspotentially blocking | 277 ms | 70.7 KB | 277 ms |
02fvhu.~ed9tm.jspotentially blocking | 260 ms | 43.7 KB | 260 ms |
| 23 more requests | all done by 1.261 s | 325.6 KB | |
119 ms | 48.9 KB | 119 ms | |
0450 ms900 msFCP · LCP 1.800 s |
The coach helps you find performance problems on your web page using web performance best practice rules. And gives you advice on privacy and best practices. Tested using Coach-core version 9.2.1.
googleTagManagerThe page is using Google Tag Manager, this is a performance risk since non-tech users can add JavaScript to your page.
Google Tag Manager makes it possible for non tech users to add scripts to your page that will downgrade performance.
longTasksThe page has 8 CPU long tasks with the total of 1.142 s. The total blocking time is 373 ms and 3 long tasks before first contentful paint with total time of 519 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 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 18.9 kB the next access.
The easiest way to make your page fast is to avoid doing requests to the server. Setting a cache header on your server response will tell the browser that it doesn't need to download the asset again during the configured cache time! Always try to set a cache time if the content doesn't change for every request.
javascriptSizeThe total JavaScript transfer size is 1.2 MB and the uncompressed size is 4.2 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?
pageSizeThe page total transfer size is 4.3 MB, which is more than the coach limit of 3 MB. That is really big and you need to make it smaller.
Avoid having pages that have a transfer size over the wire of more than 3 MB (desktop) and 2 MB (mobile) because heavy pages hurt performance and are expensive for users on metered connections. Reference: HTTP Archive median page weight in 2024 was around 2.7 MB desktop / 2.4 MB mobile, so this rule fires when a page is above the modern median.
cssSizeThe total CSS transfer size is 76.4 kB and uncompressed size is 570.2 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://prep.xelta.ai/_next/static/chunks/0bn2cukj3v_dz.css | 73.2 KB | 554.9 KB |
| https://prep.xelta.ai/_next/static/chunks/08ak-dq81l91~.css | 1.4 KB | 2.0 KB |
faviconThe favicon size is 664.1 kB bytes. That's quite big, can you make it smaller?
It is easy to make the favicon big but please avoid doing that, because every browser will then perform an unnecessarily large download. And make sure the cache headers are set for a long time for the favicon. It is easy to miss since it's another content type.
imageSizeThe page total image size is 2.2 MB. It's really big. Is the page using the right format for the images? Can they be lazy loaded? Are they compressed as good as they can be? Make them smaller by using https://imageoptim.com/.
Avoid having too many large images on the page. The images will not affect the first paint of the page, but it will eat bandwidth for the user.
responseOkThe page has 5 error responses. The page has 2 responses with code 401. The page has 2 responses with code 403. 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 19 requests that have a shorter cache time than one year (but still a cache time).
Setting a cache header is good. Setting a long cache header (a year) is even better because the asset will stay in the browser cache across visits. For content-hashed URLs (e.g. app.4af2.css) you can safely use Cache-Control: max-age=31536000, immutable. For unversioned URLs that may change, use a revalidating strategy instead.
assetsRedirectsThe page has 1 redirect. 1 of the redirects are from the base domain, please fix them!
A redirect is one extra step for the user to download the asset. Avoid that if you want to be fast. Redirects are even more of a showstopper on mobile.
compressAssetsThe 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.
| URL | Transfer | Content |
|---|---|---|
| https://prep.xelta.ai/cdn-cgi/challenge-platform/h/g/scripts/jsd/f70cb37711aa/main.js? | 10.0 KB | 21.4 KB |
optimalCssSizehttps://prep.xelta.ai/_next/static/chunks/0bn2cukj3v_dz.css size is 74.9 kB (74946) 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://prep.xelta.ai/_next/static/chunks/0bn2cukj3v_dz.css | 73.2 KB | 554.9 KB |
privateAssetsThe page has 1 request 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.
mimeTypesThe page has 1 misconfigured mime type.
It's not a great idea to let browsers guess content types (content sniffing), in some cases it can actually be a security risk.
unnecessaryHeadersThere are 1 response that sets a p3p header. There are 3 responses that sets both a max-age and expires header. There are 6 responses that sets a pragma no-cache header (that is a request header). There are 86 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.
thirdPartyThe page do 25% requests to third party domains (23 requests and 403.9 kB). First party is 69 requests and 3.9 MB. The regex .*xelta.* was used to calculate first/third party requests.
Do not load most of your content from third party URLs.
longHeadershttps://prep.xelta.a...-301v4kxxnr.woff2 has a header report-to that is 628 characters long. https://prep.xelta.a...ta.ai/_next/image has a header report-to that is 623 characters long. https://prep.xelta.a.../a23d783a7cbfca22 has a header cf-chl-out-s that is 1713 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 content-security-policy-report-only that is 1415 characters long. https://connect.face...en_US/fbevents.js has a header permissions-policy that is 874 characters long. https://connect.face.../1941936199799107 has a header content-security-policy that is 1344 characters long. https://connect.face.../1941936199799107 has a header content-security-policy-report-only that is 1415 characters long. https://connect.face.../1941936199799107 has a header permissions-policy that is 874 characters long.
Do not send response headers that are too long.
gaThe page is using Google Analytics meaning you share your users private information with Google. You should use analytics that care about user privacy, something like https://matomo.org.
Google Analytics share private user information with Google that your user hasn't agreed on sharing.
surveillanceThe page embeds 3 resources from companies that profit from user surveillance. Consider privacy-respecting alternatives.
Embedding scripts or iframes from companies whose business model is surveillance capitalism (Google, Facebook, etc.) leaks detailed user data on every page view, often before the user has had a chance to consent. See https://en.wikipedia.org/wiki/Surveillance_capitalism for background. Prefer privacy-respecting alternatives where possible.
contentSecurityPolicyHeaderSet a Content-Security-Policy header to mitigate cross-site scripting attacks. You can start with a Content-Security-Policy-Report-Only header, which only reports violations rather than blocking them.
A Content-Security-Policy response header tells the browser which sources of script, style, and other content are allowed. The most effective form is a strict CSP using nonces or hashes together with strict-dynamic; the worst is a missing header, with unsafe-inline and unsafe-eval close behind. https://web.dev/articles/strict-csp
crossOriginEmbedderPolicyHeaderSet a Cross-Origin-Embedder-Policy header (typically require-corp or credentialless) on the document response to control cross-origin embedding.
Cross-Origin-Embedder-Policy (COEP) makes the page refuse to load cross-origin subresources unless they explicitly opt in via CORP or CORS. Together with Cross-Origin-Opener-Policy it puts the page in a cross-origin isolated context, which mitigates cross-window side-channel attacks (Spectre) and unlocks high-resolution timers and SharedArrayBuffer. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cross-Origin-Embedder-Policy
crossOriginOpenerPolicyHeaderSet a Cross-Origin-Opener-Policy header (typically same-origin) on the document response to isolate the page from cross-origin windows.
Cross-Origin-Opener-Policy (COOP) lets a page sever its window-group ties to cross-origin documents that opened it or that it opens. Together with Cross-Origin-Embedder-Policy it puts the page in a cross-origin isolated context, which mitigates cross-window side-channel attacks (Spectre) and unlocks high-resolution timers and SharedArrayBuffer. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cross-Origin-Opener-Policy
crossOriginResourcePolicyHeaderSet a Cross-Origin-Resource-Policy header (same-origin, same-site or cross-origin) on the document response to limit who may embed it.
Cross-Origin-Resource-Policy (CORP) is a per-response opt-in that tells the browser which origins are allowed to embed the resource. It blocks cross-origin or cross-site no-cors embedding (img, script, iframe, etc.) and is one of the building blocks of cross-origin isolation. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cross-Origin-Resource-Policy
permissionsPolicyHeaderSet a Permissions-Policy header to control which browser features the page can use.
The Permissions-Policy response header (the successor to Feature-Policy) lets a site explicitly opt in or out of powerful browser features such as camera, microphone, geolocation, payment and clipboard. Setting a strict policy reduces the attack surface and limits what embedded third parties can do. https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Permissions-Policy
thirdPartyPrivacyThe page has 15% requests that are 3rd party (14 requests with a size of 368.1 kB). The page also have request to companies that harvest data from users and do not respect users privacy (see https://en.wikipedia.org/wiki/Surveillance_capitalism). The page do 1 tag-manager request 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 2 utility requests and uses 2 utility tools. The page do 2 social requests and uses 1 social tool. The page do 4 analytics requests 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.
A snapshot of what the browser actually built for this page: the document, how big and deep the DOM tree is and what it kept in storage. Big, deep trees are slower to style and lay out, so the counts Chrome warns about carry a flag.
Document
What the page says it is and how large it rendered.
DOM structure
How much markup the browser has to build, style and lay out.
What the page stored on the client, and the network it was tested on.
Data collected using
Coach-core version 9.2.1. With updated code from
Webappanalyzer 2026-05-04. Use
--browsertime.firefox.includeResponseBodies html or
--browsertime.chrome.includeResponseBodies html to help Wappalyzer find more information about technologies used.
Data collected using Third Party Web version 0.29.2.
0.0s1.6s2.0s2.4s2.9s3.3s3.7s6.2sWhen the page main content is rendered, collected via the Largest Contentful Paint API. Read more about Largest Contentful Paint.
body > div#app-root > div:eq(1) > main > div > div:eq(1) > div > h1
The LCP element is highlighted in the screenshot. If nothing is highlighted the element was removed before the screenshot or the LCP API couldn't find it.
How much the page's content shifts as it loads, collected via the Cumulative Layout Shift API.
No layout shifts were detected on this page.
Timing data the server chose to expose through Server-Timing response headers on the main document — typically backend time, cache status or experiment flags.
| Name | Duration | Description |
|---|---|---|
cfCacheStatus | 0 ms | DYNAMIC |
cfEdge | 7 ms | – |
cfOrigin | 0 ms | – |
cfWorker | 401 ms | – |
cfExtPri | 0 ms | – |
There are no custom configured scripts.
There are no custom extra metrics from scripting.
How the page is built.
https://prep.xelta.ai/ai-studio/xelta-prism/playground
| Header | Value |
|---|---|
alt-svc | h3=":443"; ma=86400 |
cache-control | s-maxage=50, stale-while-revalidate=31535950 |
cf-cache-status | DYNAMIC |
cf-ray | a23d783a7cbfca22-BOM |
content-encoding | zstd |
content-type | text/html; charset=utf-8 |
date | Fri, 31 Jul 2026 14:59:55 GMT |
expect-ct | max-age=86400, enforce |
nel | {"report_to":"cf-nel","success_fraction":0.0,"max_age":604800} |
priority | u=0,i |
referrer-policy | same-origin strict-origin-when-cross-origin |
report-to | {"group":"cf-nel","max_age":604800,"endpoints":[{"url":"https://a.nel.cloudflare.com/report/v4?s=Rp92o07UOVzeNdM%2FhNlVgyuU6Y9lvhoYBgxQXYmghP5JgGIRHgMYR6xLPxBcchGM%2B4%2FW0oaU%2Fo1YRhKYRHL52WO6JeiCZ1T7%2BTR21hgoK7kBr4Z1X8h%2BOdyJo2%2B501nZ"}]} |
server | cloudflare |
server-timing | cfCacheStatus;desc="DYNAMIC" cfEdge;dur=7,cfOrigin;dur=0,cfWorker;dur=401 cfExtPri |
speculation-rules | "/cdn-cgi/speculation" |
strict-transport-security | max-age=31536000; includeSubDomains; preload |
vary | rsc, next-router-state-tree, next-router-prefetch, next-router-segment-prefetch, Accept-Encoding |
x-content-type-options | nosniff |
x-frame-options | SAMEORIGIN |
x-nextjs-cache | STALE |
x-nextjs-prerender | 1 1 |
x-nextjs-stale-time | 300 |
x-xss-protection | 1; mode=block |
Transfer size4.1 MB
Content size7.4 MB
Requests86
| Content | Header Size | Transfer Size | Content Size | Requests |
|---|---|---|---|---|
| html | 0 b | 17.6 KB | 113.7 KB | 1 |
| css | 0 b | 74.6 KB | 556.8 KB | 2 |
| javascript | 0 b | 1.2 MB | 4.0 MB | 47 |
| image | 0 b | 2.1 MB | 2.1 MB | 11 |
| font | 0 b | 48.9 KB | 47.3 KB | 1 |
| favicon | 0 b | 648.6 KB | 668.8 KB | 1 |
| other | 0 b | 693 B | 151 B | 4 |
| json | 0 b | 4.8 KB | 4.8 KB | 5 |
| plain | 0 b | 4.8 KB | 12 B | 14 |
| Total | 0 b | 4.1 MB | 7.4 MB | 86 |
| Domain | Total download time | Transfer Size | Content Size | Requests |
|---|---|---|---|---|
| prep.xelta.ai | 13.801 s | 3.7 MB | 6.2 MB | 63 |
| www.googletagmanager.com | 308 ms | 180.8 KB | 548.2 KB | 1 |
| static.cloudflareinsights.com | 55 ms | 11.3 KB | 30.9 KB | 1 |
| connect.facebook.net | 196 ms | 165.0 KB | 657.3 KB | 2 |
| seob.xelta.ai | 696 ms | 248 B | 28 B | 1 |
| pmt.xelta.ai | 1.365 s | 2.9 KB | 3.6 KB | 4 |
| 1gqp45w1oa.execute-api.us-east-1.amazonaws.com | 1.562 s | 1.7 KB | 118 B | 4 |
| www.google-analytics.com | 359 ms | 56 B | 0 b | 2 |
| analytics.google.com | 338 ms | 56 B | 0 b | 2 |
| stats.g.doubleclick.net | 119 ms | 557 B | 0 b | 1 |
| www.google.co.in | 115 ms | 63 B | 42 B | 1 |
| us-assets.i.posthog.com | 1.437 s | 33.3 KB | 96.4 KB | 2 |
| cms-b.xelta.ai | 31 ms | 824 B | 43 B | 1 |
| telemetry.matchbestsoftware.online | 128 ms | 1.7 KB | 12 B | 7 |
| type | min | median | max |
|---|---|---|---|
| Expires | 0 seconds | 4 weeks | 1 year |
| Last modified | 0 seconds | 1 hour | 6 weeks |
Includes requests done after load event end.
| Content | Transfer Size | Requests |
|---|---|---|
| html | 0 b | 0 |
| css | 0 b | 0 |
| javascript | 446.6 KB | 15 |
| image | 2.0 MB | 4 |
| font | 0 b | 0 |
| favicon | 648.6 KB | 1 |
| plain | 4.8 KB | 14 |
| json | 3.7 KB | 4 |
| other | 0 b | 3 |
| Total | 3.1 MB | 46 |
Includes requests done after DOM content loaded.
| Content | Transfer Size | Requests |
|---|---|---|
| html | 0 b | 0 |
| css | 0 b | 0 |
| javascript | 446.6 KB | 15 |
| image | 2.0 MB | 4 |
| font | 0 b | 0 |
| favicon | 648.6 KB | 1 |
| plain | 4.8 KB | 14 |
| json | 3.7 KB | 4 |
| other | 0 b | 3 |
| Total | 3.1 MB | 47 |
Third party requests categorised by Third party web version 0.29.2.
Requests by category23
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.
Transfer size4.1 MB
Content size7.5 MB
Requests92
Calculated using .*xelta.* (use --firstParty to configure).
| Content | Header Size | Transfer Size | Content Size | Requests |
|---|---|---|---|---|
| html | 0 b | 17.6 KB | 113.7 KB | 1 |
| css | 0 b | 74.6 KB | 556.8 KB | 2 |
| javascript | 0 b | 790.4 KB | 2.7 MB | 41 |
| image | 0 b | 2.1 MB | 2.1 MB | 10 |
| font | 0 b | 48.9 KB | 47.3 KB | 1 |
| favicon | 0 b | 648.6 KB | 668.8 KB | 1 |
| other | 0 b | 693 B | 151 B | 2 |
| json | 0 b | 4.8 KB | 4.8 KB | 5 |
| plain | 0 b | 2.5 KB | 0 b | 2 |
| Total | N/A | 3.7 MB | 6.2 MB | 69 |
| Content | Header Size | Transfer Size | Content Size | Requests |
|---|---|---|---|---|
| html | 0 b | 0 b | 0 b | 0 |
| css | 0 b | 0 b | 0 b | 0 |
| javascript | 0 b | 390.4 KB | 1.3 MB | 6 |
| image | 0 b | 63 B | 42 B | 1 |
| font | 0 b | 0 b | 0 b | 0 |
| favicon | 0 b | 0 b | 0 b | 0 |
| other | 0 b | 0 b | 0 b | 2 |
| plain | 0 b | 2.3 KB | 12 B | 12 |
| Total | N/A | 394.5 KB | 1.3 MB | 23 |