How does PageSourceSearch know what opulist.app 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 opulist.app 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 opulist.app?

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 opulist.app?

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

opulist.app

Built with @clerk/ui 1.34.0, algoliasearch.zendesk-hc 3.0.0, lottie-web 5.13.0, @blotoutio/providers-blotout-consent-sdk 1.73.0, maplibre-gl 6.11.1, dashjs 5.2.1, posthog-js 1.434.12, @inkeep/cxkit-js 0.5.119, @reachfive/identity-core 1.42.0, @reachfive/identity-ui 2.1.0, jspdf 4.2.1, @sentry-internal/replay 10.57.0 and more. 5 pages and 116 stored files, last crawled 2026-10-02.

rank 1,065,513 27 libraries 1 identifier 16 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
@clerk/ui	1.34.0	2026-10-02
algoliasearch.zendesk-hc	3.0.0	2026-10-02
lottie-web	5.13.0	2026-10-02
@blotoutio/providers-blotout-consent-sdk	1.73.0	2026-10-02
maplibre-gl	6.11.1	2026-10-02
dashjs	5.2.1	2026-10-02
posthog-js	1.434.12	2026-10-02
@inkeep/cxkit-js	0.5.119	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
@sentry-internal/replay	10.57.0	2026-10-02
spectorjs	0.9.33	2026-10-02
@moveo-ai/web-client	0.117.0	2026-10-02
esri-leaflet-vector	4.3.2	2026-10-02
ovenplayer	0.10.54	2026-10-02
extra-map-card	1.8.0	2026-10-02
graphql-playground-react	1.7.28	2026-10-02
@recogito/annotorious	2.7.14	2026-10-02
@johanaarstein/dotlottie-player	1.5.23	2026-10-02
ogm-viewer	1.4.0	2026-10-02
@ant-design/x	2.9.0	2026-10-02
mori-chat-widget	2.0.49	2026-10-02
@watergis/mapbox-gl-export	4.0.0	2026-10-02
@joyfill/components	4.0.0-rc26	2026-10-02
veris-storybook-beta	0.1.81-react-upgrade	2026-10-02
@lottiefiles/lottie-player	2.0.12	2026-09-25

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)	o4511394404433920.ingest.us.sentry.io	view source

Third-party hosts

Hosts outside opulist.app 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
app.posthog.com	connect	view source
example.com	connect	view source
github.com	connect	view source
images.unsplash.com	connect	view source
instagram.com	connect	view source
maplibre.org	connect	view source
opulist.co	connect	view source
react.dev	connect	view source
sentry.io	connect	view source
us.i.posthog.com	connect	view source
us.posthog.com	connect	view source
va.vercel-scripts.com	connect	view source
vercel.live	connect	view source
vitals.vercel-insights.com	connect	view source
www.w3.org	connect	view source
yandex.com	connect	view source

Stored pages and scripts

The newest stored version of each file, newest first@if (p.FilesTruncated) { (the 500 newest of 116) }. 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://www.opulist.app/_next/static/chunks/9173-f5bb5344450d83f5.js	js	7.1 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/7847-c1a999fb8dfdf0fb.js	js	119.3 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/8920-f937fc9b40fa11ec.js	js	9.3 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/7383-4381b8ab55c4854b.js	js	5.1 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/7156-aeaa6cd6fe981b42.js	js	5.7 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/6515-c99e0e1ca17aa23b.js	js	8.9 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/2683-e6aca35c7468a1ef.js	js	17.6 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/1249-35072abfaecc2089.js	js	17.5 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/1796-afeee0ed995f6e72.js	js	14.5 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/2d1400c4-1ebb640f17c232fa.js	js	299 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/612-f3beeca1fa7557ca.js	js	43.4 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/3241.b3559fcf565962a0.js	js	16.3 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/c25e440e.ee3775ca9f5c6554.js	js	1006.3 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/1298.fc12020a35b02cb4.js	js	4.9 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/3465.c0595f27029223a8.js	js	5.6 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/5686.996fdf8788a7f676.js	js	17.3 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/1161.41120ab5fbe15e86.js	js	1018 B	2026-10-02	current
https://www.opulist.app/_next/static/chunks/5442.455ecd537a4ae6db.js	js	15 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/6021.171b4de5f9adf223.js	js	2 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/pages/_error-da294465ce17f1e7.js	js	608 B	2026-10-02	current
https://www.opulist.app/_next/static/xkhfzFHzMEYyz_EUxbAVL/_ssgManifest.js	js	80 B	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/xkhfzFHzMEYyz_EUxbAVL/_buildManifest.js	js	9.9 KB	2026-10-02	2026-10-02
https://www.opulist.app/_vercel/insights/script.js	js	4.4 KB	2026-10-02	current
https://www.opulist.app/_vercel/speed-insights/script.js	js	12.3 KB	2026-10-02	current
https://www.opulist.app/_next/static/chunks/app/…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	599 B	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/app/…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	595 B	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/app/…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	6.7 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/app/…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	679 B	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/app/…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	689 B	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/4065…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	47.7 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/9474…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	17.4 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/5047…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	11.4 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/901-…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	10 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/1796…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	14.5 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/7156…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	5.7 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/webp…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	4.7 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/poly…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	110 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/app/…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	24.9 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/4787…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	7.3 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/8920…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	9.3 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/7383…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	5.1 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/app/…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	4.2 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/app/…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	1.3 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/7081…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	26.9 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/8088…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	16.3 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/8917…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	16.4 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/3796…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	8.5 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/7174…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	52 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/9530…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	9.2 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/3738…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	43.8 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/app/…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	5.7 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/7434…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	45.2 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/9655…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	14.2 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/9173…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	7.1 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/2923…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	4.2 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/6387…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	20 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/6660…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	28.5 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/4589…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	7 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/7388…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	9.5 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/1268…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	30.7 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/app/…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	7.8 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/main…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	13.2 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/5321…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	418.7 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/1ba0…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	176.6 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/402e…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	169.3 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/8f16…pl_Gm9tPD3njLbv3KY3sdNR1VtGvbWM	js	117.6 KB	2026-10-02	2026-10-02
https://www.opulist.app/about	html	100.6 KB	2026-10-02	2026-10-02
https://www.opulist.app/articles	html	267.3 KB	2026-10-02	2026-10-02
https://www.opulist.app/search	html	107.9 KB	2026-10-02	2026-10-02
https://www.opulist.app/search/coffee-shop	html	108.3 KB	2026-10-02	2026-10-02
https://www.opulist.app/	html	239.5 KB	2026-10-02	2026-10-02
https://www.opulist.app/_next/static/chunks/2683-629f389f9df3dcc5.js	js	17.7 KB	2026-09-25	current
https://www.opulist.app/_next/static/vkTOPx39GcCuO5nj9BqRM/_ssgManifest.js	js	80 B	2026-09-25	current
https://www.opulist.app/_next/static/vkTOPx39GcCuO5nj9BqRM/_buildManifest.js	js	9.9 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/app/…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	599 B	2026-09-25	current
https://www.opulist.app/_next/static/chunks/app/…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	595 B	2026-09-25	current
https://www.opulist.app/_next/static/chunks/app/…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	679 B	2026-09-25	current
https://www.opulist.app/_next/static/chunks/app/…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	689 B	2026-09-25	current
https://www.opulist.app/_next/static/chunks/4065…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	47.7 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/9474…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	17.2 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/5047…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	11.4 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/901-…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	10 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/1796…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	14.5 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/7156…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	5.7 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/app/…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	6.7 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/webp…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	4.7 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/poly…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	110 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/app/…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	24.9 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/4787…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	7.3 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/8920…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	9.3 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/7383…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	5.1 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/app/…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	4.2 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/app/…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	1.3 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/7081…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	26.7 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/8088…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	16.3 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/8917…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	16.4 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/3796…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	8.5 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/7174…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	52 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/9530…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	9.2 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/3738…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	43.8 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/app/…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	5.7 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/7434…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	45.2 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/9655…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	14.2 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/9173…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	7.1 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/2923…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	4.2 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/6387…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	20 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/6660…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	28.5 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/4589…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	7 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/7388…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	9.5 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/1268…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	30.7 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/app/…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	7.8 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/main…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	13.2 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/5321…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	418.7 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/1ba0…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	176.6 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/402e…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	169.3 KB	2026-09-25	current
https://www.opulist.app/_next/static/chunks/8f16…pl_2y6HxSeNAYDMBzSo1imY1VqHSeRT	js	117.6 KB	2026-09-25	current

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, 71 files, 3.9 MB; 26 libraries, 1 identifier, 16 third-party hosts
26 libraries added
- @sentry-internal/replay 10.57.0
- @ant-design/x 2.9.0
- @inkeep/cxkit-js 0.5.119
- @clerk/ui 1.34.0
- @moveo-ai/web-client 0.117.0
- @joyfill/components 4.0.0-rc26
- mori-chat-widget 2.0.49
- spectorjs 0.9.33
- posthog-js 1.434.12
- algoliasearch.zendesk-hc 3.0.0
- @blotoutio/providers-blotout-consent-sdk 1.73.0
- jspdf 4.2.1
- and 14 more
1 identifier added
- o4511394404433920.ingest.us.sentry.io Sentry DSN host
16 third-party hosts added
- react.dev
- www.w3.org
- yandex.com
- sentry.io
- app.posthog.com
- us.i.posthog.com
- us.posthog.com
- example.com
- va.vercel-scripts.com
- instagram.com
- opulist.co
- images.unsplash.com
- and 4 more
71 files added

Questions about opulist.app

How does PageSourceSearch know what opulist.app 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 opulist.app 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 opulist.app?: 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 opulist.app?: 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.