How does PageSourceSearch know what on-this-day.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 on-this-day.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 on-this-day.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 on-this-day.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

on-this-day.com

Built with gtag, @vitest/utils 5.0.2, @contactlab/marketing-cloud-logo 6.0.0. 4 pages and 12 stored files, last crawled 2026-10-02.

rank 692,417 3 libraries 6 identifiers 9 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
gtag		2026-10-02
@vitest/utils	5.0.2	2026-10-02
@contactlab/marketing-cloud-logo	6.0.0	2026-09-24

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
AdSense publisher id (Google)	ca-pub-1004771410615065	view source
Bing site verification (Microsoft)	1622F149E68167D5B74BD96F0961ABE4	view source
Bing site verification (Microsoft)	9D7482F4B15044430B36769AE21BA910	view source
Facebook app id (Meta)	119903830460	view source
Google Analytics 4 measurement id (Google)	G-2BH9GVFY8T	view source
Google site verification (Google)	FR_B2yH1DBCZ0ogr1DiKHOeQFeH7FfNUDsedQuwLgMA	view source

Third-party hosts

Hosts outside on-this-day.com 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.pixfuture.com	script	view source
ebay.us	connect	view source
pagead2.googlesyndication.com	script	view source
seal.godaddy.com	connect	view source
served-by.pixfuture.com	script	view source
twitter.com	connect	view source
ws-na.amazon-adsystem.com	script	view source
www.googletagmanager.com	script	view source
z-na.amazon-adsystem.com	script	view source

Stored pages and scripts

The newest stored version of each file, newest first@if (p.FilesTruncated) { (the 500 newest of 12) }. 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://on-this-day.com/mobile/footer.txt	js	5.3 KB	2026-10-02	current
https://www.googletagmanager.com/gtag/js?id=G-2BH9GVFY8T	js library	not fetched	2026-10-02	current
https://on-this-day.com/feeds/feeds-topics/otd-sports.js	js	358 B	2026-10-02	current
https://on-this-day.com/onthisday/thedays/day-calendar/day-calendar-bday.js	js	594 B	2026-10-02	current
https://on-this-day.com/onthisday/thedays/day-calendar/day-calendar-music.js	js	596 B	2026-10-02	current
https://on-this-day.com/onthisday/thedays/day-calendar/day-calendar-misc.js	js	594 B	2026-10-02	current
https://on-this-day.com/mobile/headerhome.txt	js	14.5 KB	2026-10-02	current
https://on-this-day.com/mobile/header.txt	js	418 B	2026-10-02	current
https://www.on-this-day.com/cgi-bin/otd/statesotd/otdWY.pl	html	13.9 KB	2026-10-02	2026-10-02
https://on-this-day.com/cgi-bin/otd/statesotd/otdTX.pl	html	15.1 KB	2026-10-02	2026-10-02
https://www.on-this-day.com/cgi-bin/otd/quote-multi.pl	html	15.1 KB	2026-10-02	2026-10-02
https://on-this-day.com/mobile/	html	20.3 KB	2026-10-02	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

4 pages, 12 files, 86.8 KB; 2 libraries, 6 identifiers, 9 third-party hosts
2 libraries added
- gtag
- @vitest/utils 5.0.2
6 identifiers added
- G-2BH9GVFY8T Google Analytics 4 measurement id
- FR_B2yH1DBCZ0ogr1DiKHOeQFeH7FfNUDsedQuwLgMA Google site verification
- 1622F149E68167D5B74BD96F0961ABE4 Bing site verification
- 9D7482F4B15044430B36769AE21BA910 Bing site verification
- 119903830460 Facebook app id
- ca-pub-1004771410615065 AdSense publisher id
9 third-party hosts added
12 files added

Questions about on-this-day.com

How does PageSourceSearch know what on-this-day.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 on-this-day.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 on-this-day.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 on-this-day.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.