How does PageSourceSearch know what leisurelands.nl 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 leisurelands.nl 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 leisurelands.nl?

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 leisurelands.nl?

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

leisurelands.nl

Built with flatpickr 4.6.13, chart.js 4.5.1, leaflet 1.9.4, @sendcloud/checkout-plugin-ui 2.4.4, leaflet.markercluster 1.5.3, @hellotext/hellotext 2.6.0, cookiebot, @justifi/webcomponents 6.14.3, bootstrap-italia 2.18.3, esri-leaflet 3.0.19, @govbr-ds/core 3.7.0, leaflet-gesture-handling 1.2.2 and more. 5 pages and 136 stored files, last crawled 2026-10-02.

rank 1,148,911 30 libraries 1 identifier 18 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
flatpickr	4.6.13	2026-10-02
chart.js	4.5.1	2026-10-02
leaflet	1.9.4	2026-10-02
@sendcloud/checkout-plugin-ui	2.4.4	2026-10-02
leaflet.markercluster	1.5.3	2026-10-02
@hellotext/hellotext	2.6.0	2026-10-02
cookiebot		2026-10-02
@justifi/webcomponents	6.14.3	2026-10-02
bootstrap-italia	2.18.3	2026-10-02
esri-leaflet	3.0.19	2026-10-02
@govbr-ds/core	3.7.0	2026-10-02
leaflet-gesture-handling	1.2.2	2026-10-02
esri-leaflet-vector	4.3.2	2026-10-02
ol-mapbox-style	13.5.1	2026-10-02
extra-map-card	1.8.0	2026-10-02
@vitest/utils	5.0.2	2026-10-02
@gstat/leaflet-gesture-handling	1.2.8	2026-10-02
@memori.ai/memori-webcomponent	8.3.3	2026-10-02
xmlbuilder2	4.0.3	2026-10-02
@3t-transform/threeteeui	1.12.1	2026-10-02
azure-maps-control	3.7.4	2026-10-02
wonder-image	2.1.2-alpha.4	2026-10-02
@unbabel/ui	5.19.0	2026-10-02
develart-olzalogistic-pickup-points-widget	1.8.19	2026-10-02
@bmlt-enabled/croutonjs	4.3.3	2026-10-02
@contributte/datagrid	7.1.0	2026-10-02
jupyter-leaflet	0.20.0	2026-10-02
@flagship.io/js-sdk	5.2.2	2026-09-25
@oiz/stzh-components	4.16.0	2026-09-25
@chakra-ui/theme	3.4.6	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
Bing site verification (Microsoft)	0165B6DFBFDC76DB95E5AD1E4C980388	view source

Third-party hosts

Hosts outside leisurelands.nl 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
basemaps-api.arcgis.com	connect	view source
basemapstyles-api.arcgis.com	connect	view source
cdn.arcgis.com	connect	view source
cdndev.arcgis.com	connect	view source
cdnqa.arcgis.com	connect	view source
consent.cookiebot.com	script	view source
devext.arcgis.com	connect	view source
github.com	connect	view source
leafletjs.com	connect	view source
maplibre.org	connect	view source
qaext.arcgis.com	connect	view source
static.arcgis.com	connect	view source
vimeo.com	connect	view source
w.soundcloud.com	connect	view source
www.arcgis.com	connect	view source
www.esri.com	connect	view source
www.w3.org	connect	view source
www.youtube-nocookie.com	connect	view source

Stored pages and scripts

The newest stored version of each file, newest first@if (p.FilesTruncated) { (the 500 newest of 136) }. 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://consent.cookiebot.com/uc.js	js library	not fetched	2026-10-02	current
https://zakelijk.leisurelands.nl/build/9686.0f5090e5d10718959338.bundle.js	js	1.5 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/9582.048dc20b525cf1ccae11.bundle.js	js	335 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/9451.4e413ede18a45c281a0f.bundle.js	js	679 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/9389.13e2a90ccbcd1961cccd.bundle.js	js library	33.2 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/9311.4883412fbcbfa9dc95bb.bundle.js	js	3.8 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/9301.c18f6f22180f999b6706.bundle.js	js	361 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/9172.4d0ab70023929cae52c4.bundle.js	js	1.4 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/9136.caa00a4e32bc60b05389.bundle.js	js	381 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/8964.f72201909d3d9490c0fb.bundle.js	js	12.5 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/8887.ad9e124f1f411b8a7def.bundle.js	js	5.8 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/8681.69ba0c67a7f6bfa8211c.bundle.js	js	299 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/8615.6e593d6c69fffa2858ee.bundle.js	js	234 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/8512.888b314fd0ad91ed4d74.bundle.js	js	65.3 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/8344.5782aefecdc9fbce3dff.bundle.js	js	18.1 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/8150.5598cd0c25f37a40730f.bundle.js	js	466 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/7729.9e8bef4016cda44f78de.bundle.js	js	311 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/7211.48c33ff708d2834c16e5.bundle.js	js	20.1 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/6972.f05a1f25b3fbaef03c48.bundle.js	js	1.8 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/6822.e243c828227d536af554.bundle.js	js	610 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/6712.6976d544cf261711efb8.bundle.js	js	362 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/6802.e025f7bdf85c8011c792.bundle.js	js	50.2 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/6597.2c702c659c891d459d20.bundle.js	js	564 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/6547.0e25b8409f26e6937bf2.bundle.js	js	8.9 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/6486.5a8dc82ab6d160122dac.bundle.js	js	785 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/6039.2e0faab947e280a5629e.bundle.js	js	10.8 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/5937.a6650a173f9992efb8ac.bundle.js	js	967 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/5834.724b4b0409fe08cd3c2d.bundle.js	js	2.8 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/5575.668c680c70d6f4d2a314.bundle.js	js	1.7 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/5521.e2316b1a02a9f4bfc832.bundle.js	js	283 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/5379.b63a59861c5477f40d7f.bundle.js	js	299 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/5250.e11a5d6b2d8ba249d837.bundle.js	js	465 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/4867.3833c1442eed9e5a3c99.bundle.js	js	294 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/4778.06b70019e67fb099921d.bundle.js	js	680 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/4331.1f37c942a73fdbcea274.bundle.js	js	946 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/4235.e0e7b9c7500ab6fd29b9.bundle.js	js	1 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/3982.6a5e189a7987b81c6842.bundle.js	js	540 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/3690.e244baf7dec2913f8f37.bundle.js	js	660 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/3649.5a0d8c3602dc0327aadc.bundle.js	js	948 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/3617.68f899c2b4f9d4857983.bundle.js	js	209 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/3481.218f045a7216137fe8f1.bundle.js	js	145.4 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/3435.11ecf3d6a36d558b7785.bundle.js	js	440 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/3365.7342a33ed394903def3c.bundle.js	js	524 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/3249.a2a633cda67621959082.bundle.js	js	478 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/3166.2d85a1f58dc2554746aa.bundle.js	js	497 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/3042.015c77dcfe5f56dad58f.bundle.js	js	621 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/2961.829fcb2ef7bb43ce4aef.bundle.js	js	1 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/2942.420f724d0b407cbf0070.bundle.js	js	5.3 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/2862.7a37cfa381add35858e6.bundle.js	js	575 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/2793.5bdd640121e0f15889b6.bundle.js	js	64.7 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/2763.46a3d7f80d7149c91fdf.bundle.js	js	421 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/2685.b29ff5de327a268b457f.bundle.js	js	1.1 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/2383.5b89841b72e6a1ccbe84.bundle.js	js	534 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/2329.b24bc0bf1a4fae954c07.bundle.js	js	2.8 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/2254.e85cc49d4b2f5b67c03c.bundle.js	js	858.2 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/1985.294d91d13022da7c0392.bundle.js	js	1.7 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/1806.902f26b72d1fbaf880ad.bundle.js	js	312 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/1433.8c798338539de0b2e288.bundle.js	js	350 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/910.cc15b0b38f4903ae1c13.bundle.js	js	923 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/902.ef62235256b7febbf749.bundle.js	js	394 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/888.347694c3bfd2b2cf4c51.bundle.js	js	1.1 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/722.677869950f75cccf320c.bundle.js	js	711 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/250.036c51409c233c783e98.bundle.js	js	345 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/422.48eb24e34da7648f95ad.bundle.js	js	639 B	2026-10-02	current
https://www.leisurelands.nl/build/9686.0f5090e5d10718959338.bundle.js	js	1.5 KB	2026-10-02	current
https://www.leisurelands.nl/build/9582.048dc20b525cf1ccae11.bundle.js	js	335 B	2026-10-02	current
https://www.leisurelands.nl/build/9451.4e413ede18a45c281a0f.bundle.js	js	679 B	2026-10-02	current
https://www.leisurelands.nl/build/9389.13e2a90ccbcd1961cccd.bundle.js	js library	33.2 KB	2026-10-02	current
https://www.leisurelands.nl/build/9301.c18f6f22180f999b6706.bundle.js	js	361 B	2026-10-02	current
https://www.leisurelands.nl/build/9311.4883412fbcbfa9dc95bb.bundle.js	js	3.8 KB	2026-10-02	current
https://www.leisurelands.nl/build/9172.4d0ab70023929cae52c4.bundle.js	js	1.4 KB	2026-10-02	current
https://www.leisurelands.nl/build/9136.caa00a4e32bc60b05389.bundle.js	js	381 B	2026-10-02	current
https://www.leisurelands.nl/build/8964.f72201909d3d9490c0fb.bundle.js	js	12.5 KB	2026-10-02	current
https://www.leisurelands.nl/build/8887.ad9e124f1f411b8a7def.bundle.js	js	5.8 KB	2026-10-02	current
https://www.leisurelands.nl/build/8681.69ba0c67a7f6bfa8211c.bundle.js	js	299 B	2026-10-02	current
https://www.leisurelands.nl/build/8512.888b314fd0ad91ed4d74.bundle.js	js	65.3 KB	2026-10-02	current
https://www.leisurelands.nl/build/8615.6e593d6c69fffa2858ee.bundle.js	js	234 B	2026-10-02	current
https://www.leisurelands.nl/build/8344.5782aefecdc9fbce3dff.bundle.js	js	18.1 KB	2026-10-02	current
https://www.leisurelands.nl/build/8150.5598cd0c25f37a40730f.bundle.js	js	466 B	2026-10-02	current
https://www.leisurelands.nl/build/7729.9e8bef4016cda44f78de.bundle.js	js	311 B	2026-10-02	current
https://www.leisurelands.nl/build/7211.48c33ff708d2834c16e5.bundle.js	js	20.1 KB	2026-10-02	current
https://www.leisurelands.nl/build/6972.f05a1f25b3fbaef03c48.bundle.js	js	1.8 KB	2026-10-02	current
https://www.leisurelands.nl/build/6822.e243c828227d536af554.bundle.js	js	610 B	2026-10-02	current
https://www.leisurelands.nl/build/6802.e025f7bdf85c8011c792.bundle.js	js	50.2 KB	2026-10-02	current
https://www.leisurelands.nl/build/6712.6976d544cf261711efb8.bundle.js	js	362 B	2026-10-02	current
https://www.leisurelands.nl/build/6597.2c702c659c891d459d20.bundle.js	js	564 B	2026-10-02	current
https://www.leisurelands.nl/build/6547.0e25b8409f26e6937bf2.bundle.js	js	8.9 KB	2026-10-02	current
https://www.leisurelands.nl/build/6039.2e0faab947e280a5629e.bundle.js	js	10.8 KB	2026-10-02	current
https://www.leisurelands.nl/build/6486.5a8dc82ab6d160122dac.bundle.js	js	785 B	2026-10-02	current
https://www.leisurelands.nl/build/5937.a6650a173f9992efb8ac.bundle.js	js	967 B	2026-10-02	current
https://www.leisurelands.nl/build/5834.724b4b0409fe08cd3c2d.bundle.js	js	2.8 KB	2026-10-02	current
https://www.leisurelands.nl/build/5575.668c680c70d6f4d2a314.bundle.js	js	1.7 KB	2026-10-02	current
https://www.leisurelands.nl/build/5521.e2316b1a02a9f4bfc832.bundle.js	js	283 B	2026-10-02	current
https://www.leisurelands.nl/build/5379.b63a59861c5477f40d7f.bundle.js	js	299 B	2026-10-02	current
https://www.leisurelands.nl/build/5250.e11a5d6b2d8ba249d837.bundle.js	js	465 B	2026-10-02	current
https://www.leisurelands.nl/build/4867.3833c1442eed9e5a3c99.bundle.js	js	294 B	2026-10-02	current
https://www.leisurelands.nl/build/4331.1f37c942a73fdbcea274.bundle.js	js	946 B	2026-10-02	current
https://www.leisurelands.nl/build/4778.06b70019e67fb099921d.bundle.js	js	680 B	2026-10-02	current
https://www.leisurelands.nl/build/4235.e0e7b9c7500ab6fd29b9.bundle.js	js	1 KB	2026-10-02	current
https://www.leisurelands.nl/build/3982.6a5e189a7987b81c6842.bundle.js	js	540 B	2026-10-02	current
https://www.leisurelands.nl/build/3690.e244baf7dec2913f8f37.bundle.js	js	660 B	2026-10-02	current
https://www.leisurelands.nl/build/3649.5a0d8c3602dc0327aadc.bundle.js	js	948 B	2026-10-02	current
https://www.leisurelands.nl/build/3481.218f045a7216137fe8f1.bundle.js	js	145.4 KB	2026-10-02	current
https://www.leisurelands.nl/build/3617.68f899c2b4f9d4857983.bundle.js	js	209 B	2026-10-02	current
https://www.leisurelands.nl/build/3435.11ecf3d6a36d558b7785.bundle.js	js	440 B	2026-10-02	current
https://www.leisurelands.nl/build/3365.7342a33ed394903def3c.bundle.js	js	524 B	2026-10-02	current
https://www.leisurelands.nl/build/3249.a2a633cda67621959082.bundle.js	js	478 B	2026-10-02	current
https://www.leisurelands.nl/build/3166.2d85a1f58dc2554746aa.bundle.js	js	497 B	2026-10-02	current
https://www.leisurelands.nl/build/3042.015c77dcfe5f56dad58f.bundle.js	js	621 B	2026-10-02	current
https://www.leisurelands.nl/build/2961.829fcb2ef7bb43ce4aef.bundle.js	js	1 KB	2026-10-02	current
https://www.leisurelands.nl/build/2942.420f724d0b407cbf0070.bundle.js	js	5.3 KB	2026-10-02	current
https://www.leisurelands.nl/build/2862.7a37cfa381add35858e6.bundle.js	js	575 B	2026-10-02	current
https://www.leisurelands.nl/build/2793.5bdd640121e0f15889b6.bundle.js	js	64.7 KB	2026-10-02	current
https://www.leisurelands.nl/build/2763.46a3d7f80d7149c91fdf.bundle.js	js	421 B	2026-10-02	current
https://www.leisurelands.nl/build/2685.b29ff5de327a268b457f.bundle.js	js	1.1 KB	2026-10-02	current
https://www.leisurelands.nl/build/2383.5b89841b72e6a1ccbe84.bundle.js	js	534 B	2026-10-02	current
https://www.leisurelands.nl/build/2329.b24bc0bf1a4fae954c07.bundle.js	js	2.8 KB	2026-10-02	current
https://www.leisurelands.nl/build/2254.e85cc49d4b2f5b67c03c.bundle.js	js	858.2 KB	2026-10-02	current
https://www.leisurelands.nl/build/1985.294d91d13022da7c0392.bundle.js	js	1.7 KB	2026-10-02	current
https://www.leisurelands.nl/build/1806.902f26b72d1fbaf880ad.bundle.js	js	312 B	2026-10-02	current
https://www.leisurelands.nl/build/1433.8c798338539de0b2e288.bundle.js	js	350 B	2026-10-02	current
https://www.leisurelands.nl/build/910.cc15b0b38f4903ae1c13.bundle.js	js	923 B	2026-10-02	current
https://www.leisurelands.nl/build/902.ef62235256b7febbf749.bundle.js	js	394 B	2026-10-02	current
https://www.leisurelands.nl/build/888.347694c3bfd2b2cf4c51.bundle.js	js	1.1 KB	2026-10-02	current
https://www.leisurelands.nl/build/722.677869950f75cccf320c.bundle.js	js	711 B	2026-10-02	current
https://www.leisurelands.nl/build/422.48eb24e34da7648f95ad.bundle.js	js	639 B	2026-10-02	current
https://www.leisurelands.nl/build/250.036c51409c233c783e98.bundle.js	js	345 B	2026-10-02	current
https://zakelijk.leisurelands.nl/build/main.159c21f3041290e9ff51.bundle.js	js	550.2 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/build/runtime.d08812286489488bc5f5.bundle.js	js	6.1 KB	2026-10-02	current
https://www.leisurelands.nl/build/main.159c21f3041290e9ff51.bundle.js	js	550.2 KB	2026-10-02	current
https://www.leisurelands.nl/build/runtime.d08812286489488bc5f5.bundle.js	js	6.1 KB	2026-10-02	current
https://zakelijk.leisurelands.nl/nl/projecten	html	59.1 KB	2026-10-02	current
https://www.leisurelands.nl/nl/ontdek-recreatiegebieden-leisurelands	html	196.5 KB	2026-10-02	current
https://www.leisurelands.nl/nl/contact	html	49 KB	2026-10-02	current
https://www.leisurelands.nl/nl/blogs	html	88.2 KB	2026-10-02	current
https://www.leisurelands.nl/nl	html	170.4 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, 136 files, 4.3 MB; 27 libraries, 1 identifier, 18 third-party hosts
27 libraries added
- @vitest/utils 5.0.2
- @3t-transform/threeteeui 1.12.1
- wonder-image 2.1.2-alpha.4
- @justifi/webcomponents 6.14.3
- chart.js 4.5.1
- @contributte/datagrid 7.1.0
- @hellotext/hellotext 2.6.0
- jupyter-leaflet 0.20.0
- @memori.ai/memori-webcomponent 8.3.3
- @gstat/leaflet-gesture-handling 1.2.8
- leaflet 1.9.4
- xmlbuilder2 4.0.3
- and 15 more
1 identifier added
- 0165B6DFBFDC76DB95E5AD1E4C980388 Bing site verification
18 third-party hosts added
- consent.cookiebot.com
- www.w3.org
- leafletjs.com
- github.com
- www.arcgis.com
- devext.arcgis.com
- qaext.arcgis.com
- cdn.arcgis.com
- cdndev.arcgis.com
- cdnqa.arcgis.com
- maplibre.org
- basemapstyles-api.arcgis.com
- and 6 more
136 files added

Questions about leisurelands.nl

How does PageSourceSearch know what leisurelands.nl 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 leisurelands.nl 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 leisurelands.nl?: 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 leisurelands.nl?: 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.