How does PageSourceSearch know what www.nhs.uk 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 www.nhs.uk 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 www.nhs.uk?

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 www.nhs.uk?

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

www.nhs.uk

Built with tw-elements 2.0.0, p5 2.3.3. 5 pages and 9 stored files.

rank 2,954 2 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
tw-elements	2.0.0	2026-09-24
p5	2.3.3	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 www.nhs.uk.

Stored pages and scripts

The newest stored version of each file, newest first@if (p.FilesTruncated) { (the 500 newest of 9) }. 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.nhs.uk/service-search/dist/js/nhsuk-frontend-10.4.2.min.js	js	47.5 KB	2026-09-24	current
https://www.nhs.uk/service-search/dist/js/nhsapp…1af5bf075064c5e871dd1a08f8c3.js	js	4.4 KB	2026-09-24	current
https://www.nhs.uk/service-search/dist/js/app.mi…caff37a0461331c868959c1f4b1c.js	js	14.3 KB	2026-09-24	current
https://www.nhs.uk/static/nhsuk/js/main.3960f67a4f14.js	js	102.8 KB	2026-09-24	current
https://www.nhs.uk/health-a-to-z/	html	24.1 KB	2026-09-24	current
https://www.nhs.uk/nhs-app/	html	22.5 KB	2026-09-24	current
https://www.nhs.uk/service-search/pharmacy/find-a-pharmacy	html	16.6 KB	2026-09-24	current
https://www.nhs.uk/using-the-nhs/about-the-nhs/	html	22.9 KB	2026-09-24	current
https://www.nhs.uk/	html	31.4 KB	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 www.nhs.uk

How does PageSourceSearch know what www.nhs.uk 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 www.nhs.uk 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 www.nhs.uk?: 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 www.nhs.uk?: 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.