How does PageSourceSearch know what heyfomo.cz is built with?

From the site's own source code. The crawler stores the exact bytes of its pages and first-party scripts; the libraries are recognised by fingerprinting that code against known releases, the identifiers are read out of the tag snippets, and the third-party hosts are the script, iframe and stylesheet sources in the HTML and the absolute URLs inside the scripts. Nothing is inferred from headers or guessed.

How far back does the history of heyfomo.cz go?

To the first crawl the timeline lists. Every crawl records what the site looked like; when a file's content changes, its earlier version stays viewable because the stored chunks are never deleted, only mapped. A crawl that finds a file unchanged adds no copy.

Can I see an older version of a script from heyfomo.cz?

Yes. In the stored files list, every date under a file opens the version that was live at that crawl, with the same viewer as the current one. The raw bytes can be downloaded from there.

Which other websites use the same tracking IDs as heyfomo.cz?

Each identifier links to its reverse lookup, the list of every site in the index whose source carries the same id: the sites one analytics property or tag manager container is shared across.

Site profile

heyfomo.cz

Built with gtm, @clerk/ui 1.34.0, @zonos/elements 1.3.289, dashjs 5.2.1, stripe-js 2.4.0, @reachfive/identity-core 1.42.0, @reachfive/identity-ui 2.1.0, jspdf 4.2.1, cloudflare-insights, mdbootstrap 4.20.0, cloudflare-email-decode, fusioncharts 4.2.2 and more. 5 pages and 110 stored files, last crawled 2026-10-02.

rank 1,173,703 17 libraries 1 identifier 38 third-party hosts 1 crawl open the site

Technologies and libraries

Recognised by fingerprinting the stored files and bundles against known releases; a version is the release the bytes match.

Library	Version	Seen
gtm		2026-10-02
@clerk/ui	1.34.0	2026-10-02
@zonos/elements	1.3.289	2026-10-02
dashjs	5.2.1	2026-10-02
stripe-js	2.4.0	2026-10-02
@reachfive/identity-core	1.42.0	2026-10-02
@reachfive/identity-ui	2.1.0	2026-10-02
jspdf	4.2.1	2026-10-02
cloudflare-insights		2026-10-02
mdbootstrap	4.20.0	2026-10-02
cloudflare-email-decode		2026-10-02
fusioncharts	4.2.2	2026-10-02
ovenplayer	0.10.54	2026-10-02
graphql-playground-react	1.7.28	2026-10-02
@recogito/annotorious	2.7.14	2026-10-02
@story-telling-reporter/react-embed-code-generator	2.2.20	2026-10-02
comindware.core.ui	2.1.149	2026-10-02

Tracking, tag and verification IDs

Public identifiers read out of the source. Each links to every other site in the index that carries the same one.

What	Value	Found in
Sentry DSN host (Sentry)	o813775.ingest.sentry.io	view source

Third-party hosts

Hosts outside heyfomo.cz that its pages load scripts, frames or stylesheets from, and that its own scripts name in absolute URLs (connect). Each links to every site loading from the same host.

Host	Loaded as	Found in
cdn.cpex.cz	script	view source
cdn.jsdelivr.net	connect	view source
cdnjs.cloudflare.com	script	view source
data.eu.cntmbr.com	connect	view source
embed.cloudflarestream.com	connect	view source
example.com	connect	view source
fonts.googleapis.com	stylesheet	view source
github.com	connect	view source
google.com	connect	view source
iframe.cloudflarestream.com	connect	view source
iframely.net	connect	view source
img2.cncenter.cz	connect	view source
imgctx.com	connect	view source
instagram.com	connect	view source
js.stripe.com	connect	view source
login.cncenter.cz	connect	view source
open.spotify.com	connect	view source
picsum.photos	connect	view source
platform.twitter.com	connect	view source
player.vimeo.com	connect	view source
reactjs.org	connect	view source
s3.eu-central-1.amazonaws.com	connect	view source
schema.org	connect	view source
static.cloudflareinsights.com	script	view source
stripe.com	connect	view source
vercel.live	connect	view source
videodelivery.net	connect	view source
w.cncenter.cz	stylesheet	view source
watch.videodelivery.net	connect	view source
www.cncenter.cz	connect	view source
www.example.com	connect	view source
www.facebook.com	connect	view source
www.googletagmanager.com	connect	view source
www.instagram.com	connect	view source
www.tiktok.com	connect	view source
www.w3.org	connect	view source
www.youtube-nocookie.com	connect	view source
www.youtube.com	connect	view source

Stored pages and scripts

The newest stored version of each file, newest first@if (p.FilesTruncated) { (the 500 newest of 110) }. Versions are the crawls at which the file was new or its content changed; each opens the file as it was then, rebuilt from the same stored chunks.

File	Kind	Size	Collected	Versions
https://cdnjs.cloudflare.com/polyfill/v3/polyfil…dia%2ClocalStorage%2CglobalThis	js library	not fetched	2026-10-02	current
https://heyfomo.cz/_next/static/chunks/9955.d531145207c8eb57.js	js	3.6 KB	2026-10-02	2026-10-02
https://static.cloudflareinsights.com/beacon.min…85bb4c19e7a9bdbcba1788362987495	js library	not fetched	2026-10-02	current
https://www.googletagmanager.com/gtm.js?id=	js library	not fetched	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/9531.b4be0508b50e7eab.js	js	7.5 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/9468.4113fc3d22d2b183.js	js	7.2 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/9417.58b634d8c266c9de.js	js	1.6 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/9385.39d096d208606bab.js	js	6 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/9227.a7975336ae7a8bf9.js	js	14.5 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/9126.1ef6ddc9795d41c4.js	js	9.4 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/9007.b129e6be6a00478d.js	js	9.8 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/8984.d01916d0c8a65218.js	js	4.9 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/8841.7118a6686f679c9b.js	js	2.9 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/8752.77186d8266426422.js	js	3.7 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/8680.aef25be661689488.js	js	2.3 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/8602.ade015e029a43c82.js	js	6.5 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/8351.55cb508950e74309.js	js	1.2 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/8319.7328e516ec3cf194.js	js	816 B	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/8200.5c5c34221bd710a6.js	js	7.2 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/8060.36b0a0fe04aa7bf7.js	js	3.3 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/7966.8f95101e702af7ad.js	js	5.1 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/7785.067b4cde7718460d.js	js	9.7 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/7958.505d8a5ceb6e0e80.js	js	2.8 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/7606.bc1e0bacceff44ae.js	js	57.9 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/7182.1a4956021c8acd96.js	js	1.8 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/7143.7925b55a74395e04.js	js	10.8 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/7081.65f49f8564d27605.js	js	3.1 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/6952.2709f3247e6df234.js	js	3.5 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/6895.af2b183bd51b02f4.js	js	3 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/6848.a7385f6a840a5729.js	js	13.2 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/6644.cf89b3f6f2014188.js	js	20.2 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/6519.094260d548ba5ab1.js	js	1.6 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/6440.901306d10fb007d4.js	js	3.8 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/6161.138fe17bc090a246.js	js	15.8 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/6258.47477a9a7cf88b4b.js	js	3.6 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/6106.89dfca72ea8496d0.js	js	2 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/6012.16eaa2dbf420428c.js	js	6.6 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/5818.4c80dcc08b983ba4.js	js	4.4 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/5223.84ac2c1a1ef99349.js	js	9.7 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/4805.ffe616f4ee6ecf96.js	js	10.8 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/4730.fd47bbf9485cf125.js	js	790 B	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/4338.6308a6bc5b5b04b3.js	js	9.8 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/4345.6b6b8a504ee838ca.js	js	1.5 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/4096.9d124ac3247f8b35.js	js	15.8 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/4081.a365faefe11506c0.js	js	1.2 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/3819.1dbebbab2ffc33e3.js	js	18.6 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/3818.96826f2c56348036.js	js	9.4 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/3609.5e86858b50822563.js	js	732 B	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/3570.5756c1380a3bcce1.js	js	4.4 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/3526.1a34658d90f55c48.js	js	1.6 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/3417.e3f54a1eabb486fe.js	js	6.7 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/2864.acc38ad15cab6156.js	js	1.5 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/2757.55e2a510dcce44da.js	js	4 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/2472.5bf2439974216ae9.js	js	4.3 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/2464.20d077af43b0714b.js	js	1.9 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/2270.37f4628069d0397a.js	js	8.4 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/2130.d4e0763939abf607.js	js	24.6 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/2115.a54d0b5ae8e36128.js	js	10.9 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/1669.d0dc4891a2a9ff3e.js	js	12.5 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/1751.e7917e4818acb0ad.js	js	1.1 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/1138.a83ba2e46cef509f.js	js	15.9 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/1031.9b20b9c0a479d766.js	js	1.9 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/781.686443ea1ae4a06e.js	js	3.2 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/434.960d509e94e6684e.js	js	10.6 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/506.4b081895c5ddb3a4.js	js	2 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/264.e1dcc53d323e22ae.js	js	5.1 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/233.021a26a1444b2e9b.js	js	2.2 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/5a6123df.43a70ffed1af3d66.js	js	206.2 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/98309536.87405c5c91f1dc23.js	js	58.5 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/[[...url]]-bd2edcb0322d9750.js	js	12.1 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/sit…/[sitemap]-73197dea58971ac9.js	js	729 B	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/sitemap.xml-e152e9cf7f669059.js	js	723 B	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/sign/in-514986cc9797dbb9.js	js	1.1 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/sg/…tyleguide]]-4a7bf323fdfb1d64.js	js	16.8 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/256-d786dd54793ba180.js	js	9.3 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/seznam-rss.xml-147d43d785219dbf.js	js	730 B	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/rss.xml-66904cdbea9ac1e6.js	js	716 B	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/newton-94d57847d81f7511.js	js	752 B	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/llms.txt-0afb95adb7478c69.js	js	716 B	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/fomo-tools-6f4fe1bd962c1133.js	js	2.7 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/check/sentry-697d297ce5b4b3af.js	js	1.1 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/check/imgix-c56b8a01e5fcc0ac.js	js	737 B	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/_error-01366a821e54101d.js	js	1.1 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/404-8b21c7f971edb0bc.js	js	11.4 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/6976.26bfd6364face181.js	js	10.4 KB	2026-10-02	2026-10-02
https://heyfomo.cz/cdn-cgi/scripts/5c5dd728/clou…/email-decode.min.js	js	1.2 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/cRaR8LS5ZCSc0bDtgCj5j/_ssgManifest.js	js	80 B	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/cRaR8LS5ZCSc0bDtgCj5j/_buildManifest.js	js	1.7 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/%5B…..url%5D%5D-bd2edcb0322d9750.js	js	12.1 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/pages/_app-29e96b5868bcb43b.js	js	1.9 MB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/main-276ecc0b98f09ed6.js	js	132.3 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/framework-1641e5c9fd0b578b.js	js	137 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/webpack-d517b1aa2be9c082.js	js	6.1 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/3313.3d3de0256147fb90.js	js	36.7 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/338.05c25ecebd96d96c.js	js	12.6 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/459.0124505a97c54c4b.js	js	43.1 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/3079.db40eb78acddd2c9.js	js	13.2 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/181-ebdb81dd4056535d.js	js	22.4 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/5858.08bce7655a03533a.js	js	15.8 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/1602-549b9598cc1ea9b6.js	js	10.2 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/4058.707c9abbc4904c5e.js	js	34.6 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/4284.30a9cd88f4b3fafb.js	js	17.6 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/699.70fa360c9638827c.js	js	14.4 KB	2026-10-02	2026-10-02
https://heyfomo.cz/_next/static/chunks/polyfills-42372ed130431b0a.js	js	110 KB	2026-10-02	2026-10-02
https://heyfomo.cz/scripts/gtmService-3.0.4.js	js	68.4 KB	2026-10-02	2026-10-02
https://heyfomo.cz/tag/astro	html	3.8 MB	2026-10-02	2026-10-02
https://heyfomo.cz/tag/viral	html	3.8 MB	2026-10-02	2026-10-02
https://heyfomo.cz/tag/celebs	html	3.8 MB	2026-10-02	2026-10-02
https://heyfomo.cz/tag/news	html	1.5 MB	2026-10-02	2026-10-02
https://heyfomo.cz/	html	385.5 KB	2026-10-02	2026-10-02

Timeline

One entry per crawl, newest first, with what changed since the crawl before: libraries, identifiers, third-party hosts and files. Historical versions stay viewable because the stored chunks are shared between versions, never copied.

2026-10-02 first crawl

5 pages, 110 files, 16.7 MB; 17 libraries, 1 identifier, 38 third-party hosts
17 libraries added
- cloudflare-email-decode
- comindware.core.ui 2.1.149
- mdbootstrap 4.20.0
- @zonos/elements 1.3.289
- jspdf 4.2.1
- @reachfive/identity-core 1.42.0
- @reachfive/identity-ui 2.1.0
- ovenplayer 0.10.54
- @recogito/annotorious 2.7.14
- dashjs 5.2.1
- graphql-playground-react 1.7.28
- stripe-js 2.4.0
- and 5 more
1 identifier added
- o813775.ingest.sentry.io Sentry DSN host
38 third-party hosts added
110 files added

Questions about heyfomo.cz

How does PageSourceSearch know what heyfomo.cz is built with?: From the site's own source code. The crawler stores the exact bytes of its pages and first-party scripts; the libraries are recognised by fingerprinting that code against known releases, the identifiers are read out of the tag snippets, and the third-party hosts are the script, iframe and stylesheet sources in the HTML and the absolute URLs inside the scripts. Nothing is inferred from headers or guessed.
How far back does the history of heyfomo.cz go?: To the first crawl the timeline lists. Every crawl records what the site looked like; when a file's content changes, its earlier version stays viewable because the stored chunks are never deleted, only mapped. A crawl that finds a file unchanged adds no copy.
Can I see an older version of a script from heyfomo.cz?: Yes. In the stored files list, every date under a file opens the version that was live at that crawl, with the same viewer as the current one. The raw bytes can be downloaded from there.
Which other websites use the same tracking IDs as heyfomo.cz?: Each identifier links to its reverse lookup, the list of every site in the index whose source carries the same id: the sites one analytics property or tag manager container is shared across.

Look up another site, browse sites by tracking ID, third-party host or technology. Site owners: see the crawler page for how stored pages are removed.