How does PageSourceSearch know what regex101.com 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 regex101.com 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 regex101.com?

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 regex101.com?

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

regex101.com

Built with mathjax 4.1.3, webpack, @covet-pics/covet-pics-widget 0.179.0, @wix/design-system 1.328.0, pdfjs-dist 6.3.289, echarts 6.1.0, @miso.ai/client-sdk 1.13.1, @highlightjs/cdn-assets 11.12.0, raleigh-map-components 1.0.9, klaro 0.7.21, @feathery/react 2.96.0, @antv/g2 5.4.8 and more. 5 pages and 122 stored files.

rank 3,227 83 libraries 0 identifiers 0 third-party hosts 0 crawls 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
mathjax	4.1.3	2026-10-01
webpack		2026-10-01
@covet-pics/covet-pics-widget	0.179.0	2026-10-01
@wix/design-system	1.328.0	2026-10-01
pdfjs-dist	6.3.289	2026-10-01
echarts	6.1.0	2026-10-01
@miso.ai/client-sdk	1.13.1	2026-10-01
@highlightjs/cdn-assets	11.12.0	2026-10-01
raleigh-map-components	1.0.9	2026-10-01
klaro	0.7.21	2026-10-01
@feathery/react	2.96.0	2026-10-01
@antv/g2	5.4.8	2026-10-01
jszip	3.10.2	2026-10-01
kore-web-sdk	11.28.1	2026-10-01
recharts	3.10.1	2026-10-01
@cognigy/webchat	3.50.0	2026-10-01
dynamsoft-barcode-reader-bundle	11.6.3200	2026-10-01
@sentry-internal/replay	10.57.0	2026-10-01
@brainfish-ai/web-tracker	0.0.33	2026-10-01
pdf-parse	2.4.5	2026-10-01
spectorjs	0.9.33	2026-10-01
universalviewer	4.4.4	2026-10-01
videojsadx	4.1.2	2026-10-01
@moveo-ai/web-client	0.117.0	2026-10-01
mammoth	1.12.3	2026-10-01
@tolgee/web	7.2.1	2026-10-01
@embedpdf/snippet	2.15.1	2026-10-01
biel-search	0.1.89	2026-10-01
vditor	4.0.0	2026-10-01
@opentok/client	2.35.2	2026-10-01
@revenuecat/purchases-js-hybrid-mappings	19.3.1	2026-10-01
agora-rtm-sdk	2.3.0	2026-10-01
@vitest/utils	5.0.2	2026-10-01
pdfjs-viewer-element	4.1.0	2026-10-01
mammoth-plus	2.0.2	2026-10-01
scanbot-web-sdk	9.0.0	2026-10-01
@betterbugs/web-sdk	0.0.47	2026-10-01
opensheetmusicdisplay	2.1.3	2026-10-01
@dnd-kit/core	6.3.1	2026-10-01
recharts-scale	0.4.5	2026-10-01
@pdftron/pdfjs-express-viewer	8.7.5	2026-10-01
x_ite	16.4.1	2026-10-01
@descope/web-components-ui	3.21.0	2026-10-01
ideogram	1.53.0	2026-10-01
@configcat/sdk	1.1.0	2026-10-01
@teipublisher/pb-components	3.6.8	2026-10-01
staffbase-widget-dacast	1.0.5	2026-10-01
@accusoft/pdf-viewer	3.11.158639	2026-10-01
holidoit	1.0.163	2026-10-01
grapesjs	0.23.6	2026-10-01
dmn-js	17.12.0	2026-10-01
@digital-realty/ui-service-management	16.0.3	2026-10-01
@banksapitechnology/embeddable-finance-web-components	1.10.0	2026-10-01
mori-chat-widget	2.0.49	2026-10-01
@stytch/vanilla-js	6.3.0	2026-10-01
cobrowse-sdk-js	3.28.7	2026-10-01
@isle-project/dll	0.50.65	2026-10-01
scichart	6.0.1	2026-10-01
@inkeep/agents-ui-js-cloud	0.17.8	2026-10-01
@formbird/angular-elements	8.5.10	2026-10-01
@unidy.io/sdk	1.12.0	2026-10-01
wonder-image	2.1.2-alpha.4	2026-10-01
@joyfill/components	4.0.0-rc26	2026-10-01
@percy.ai/your-team	1.1.10	2026-10-01
@pyscript/core	0.7.31	2026-10-01
@sentry/node-core	10.75.2	2026-10-01
@ignf-geoportal/sdk-2d	3.5.6	2026-10-01
sweph-wasm	2.6.9	2026-10-01
docxodus	12.6.2	2026-10-01
genesys-cloud-webrtc-sdk	14.2.4	2026-10-01
@solace-health/solace-entry-widget	2.0.5	2026-10-01
@openplayerjs/ads	3.6.5	2026-10-01
@clerk/ui	1.34.0	2026-09-24
dayjs	1.11.23	2026-09-24
@marimo-team/frontend	0.25.0	2026-09-24
@inkeep/cxkit-js	0.5.119	2026-09-24
exceljs	4.4.0	2026-09-24
pdfmake	0.3.11	2026-09-24
shopar-plugin	1.2.3	2026-09-24
dynamsoft-capture-vision-std	1.4.21	2026-09-24
bootstrap-italia	2.18.3	2026-09-24
pushfeedback	0.1.85	2026-09-24
@scalar/api-reference	1.71.0	2026-09-24

Tracking, tag and verification IDs

No analytics property, tag manager container, pixel or site-verification token was found in the stored source.

Third-party hosts

The stored pages and scripts reference no host outside regex101.com.

Stored pages and scripts

The newest stored version of each file, newest first@if (p.FilesTruncated) { (the 500 newest of 122) }. 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
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https://regex101.com/static/formatRegex.d83b8cc3e5b92a628967.chunk.js	js	11.3 KB	2026-10-01	current
https://regex101.com/static/markdownContainer.33c47bfaec34f726c447.chunk.js	js	1.3 KB	2026-10-01	current
https://regex101.com/static/vendors-markdownCont…y.c845ca0798c2995e1b63.chunk.js	js	109.5 KB	2026-10-01	current
https://regex101.com/static/regexDebuggerDialog.c879ad6ed1bfb0128e7f.chunk.js	js	39.7 KB	2026-10-01	current
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https://regex101.com/static/vendors-markdownCont…r.2d527f1494b6c69d3745.chunk.js	js	44.9 KB	2026-10-01	current
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https://regex101.com/static/vendors-benchmarkDia…e.c5543f4e37a82db81990.chunk.js	js	364.1 KB	2026-10-01	current
https://regex101.com/static/vendors-regexDebugge…g.834ecfc875d0292c0b90.chunk.js	js	509.6 KB	2026-10-01	current
https://regex101.com/static/vendors-sentry.eadbccc288e5b8448601.chunk.js	js	510.6 KB	2026-10-01	current
https://regex101.com/static/vendors-enterprisePr…g.e510e7d626a681fad32d.chunk.js	js	20 KB	2026-10-01	current
https://regex101.com/static/vendors-.6c006288a2a0b02dcafd.chunk.js	js	1 MB	2026-10-01	current
https://regex101.com/static/vendors-codeGenerato…g.814cfae34e0eba40d18a.chunk.js	js	76.3 KB	2026-10-01	current
https://regex101.com/static/shareDialogs.c6584e20b4ad03885d4f.chunk.js	js	24.2 KB	2026-10-01	current
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https://regex101.com/static/fonts.b10e30180431bbe0aeba.js	js	420 B	2026-10-01	current
https://regex101.com/static/enterprisePricingDia…g.8065d55ff894e7689351.chunk.js	js	7.9 KB	2026-10-01	current
https://regex101.com/static/e23d328b636dfface6c0.js	js	12.7 KB	2026-10-01	current
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https://regex101.com/static/732935176d4d50921654.js	js	10.8 KB	2026-10-01	current
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https://regex101.com/static/6c93d86544c8641b03e7.js	js	15.8 KB	2026-10-01	current
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https://regex101.com/substitution-pipeline	html	62.9 KB	2026-10-01	current
https://regex101.com/unit-tests	html	66 KB	2026-10-01	current
https://regex101.com/extraction	html	69.6 KB	2026-10-01	current
https://regex101.com/substitution	html	70.4 KB	2026-10-01	current
https://regex101.com/	html	69 KB	2026-10-01	current
https://regex101.com/static/vendors-polyfills.84db428c3365fdd1ed1f.chunk.js	js	19.1 KB	2026-09-24	current
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https://regex101.com/static/polyfills.266b697294d051ecc906.chunk.js	js	618 B	2026-09-24	current
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https://regex101.com/static/substitutionPipeline.ebdf39e6ada9cd1f1102.chunk.js	js	24.1 KB	2026-09-24	current
https://regex101.com/static/redosAnalysis.8af011468b775b279c4e.chunk.js	js	13.6 KB	2026-09-24	current
https://regex101.com/static/vendors-benchmarkDia…e.b5cc2a6fce38f8fe1415.chunk.js	js	364.1 KB	2026-09-24	current
https://regex101.com/static/vendors-regexDebugge…g.ad3954d5d62728c48042.chunk.js	js	509.6 KB	2026-09-24	current
https://regex101.com/static/vendors-sentry.81ff02424aae4bc82b25.chunk.js	js	510.6 KB	2026-09-24	current
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https://regex101.com/static/shareDialogs.cc69e8c2a12b1724851e.chunk.js	js	23.6 KB	2026-09-24	current
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https://regex101.com/static/quizPage.c3fe2dc68f480b6830a5.chunk.js	js	21.9 KB	2026-09-24	current
https://regex101.com/static/matchExporterDialog.94a620296d750080d4c8.chunk.js	js	9.1 KB	2026-09-24	current
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https://regex101.com/static/fonts.100780d705330a843391.js	js	420 B	2026-09-24	current
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https://regex101.com/static/default--.f0c23f37ba57acc662ee.chunk.js	js	79.8 KB	2026-09-24	current
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https://regex101.com/static/1217.d215bc1a299b7b5b8201.chunk.js	js	2.8 KB	2026-09-24	current
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https://regex101.com/static/vendors-bundle.3ab4f46334122252de42.js	js	1.2 MB	2026-09-24	current

Timeline

No crawl has recorded a snapshot of this site yet; snapshots are written by every crawl from now on.

Questions about regex101.com

How does PageSourceSearch know what regex101.com 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 regex101.com 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 regex101.com?: 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 regex101.com?: 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.