Will the Library ask before crawling?

It normally notifies site owners first, except for government websites. Some collections also request permission to archive the content or make it available away from Library premises.

Does Library Of Congress Web Archiving obey robots.txt?

Generally not. Its crawler is instructed to bypass robots.txt so excluded resources do not prevent an accurate replay of the archived site.

How often does the archive return?

The schedule depends on the collection and how quickly the source changes. The Library lists weekly, monthly, and quarterly as common frequencies, with some sites captured less often.

Is www.loc.gov a reliable robots.txt token for this crawler?

No. That text is part of the information URL in the recorded user agent. Ask the program for current identifying details if a firewall or allowlist decision depends on verification.

Does this archival crawl contribute to AI search or training?

The Library documents preservation and research access, not AI answer retrieval or general-purpose model training. A visit has no stated effect on AI search visibility.

Library Of Congress Web Archiving Bot Guide

What is Library Of Congress Web Archiving?

Subject experts at the Library of Congress select websites for the Library's web archive. Each selection begins with one or more seed URLs, which may point to a single document, a section, or an entire domain. The Library normally notifies site owners before collection, except for government sites, and some projects ask for permission to archive or provide off-site access.

Heritrix is the program's main crawler. It follows links from a seed and downloads page resources needed for preservation. A project may capture a changing site weekly, monthly, or quarterly, while a less active selection can be visited on a longer interval.

The Library generally bypasses robots.txt because blocked images, CSS, and JavaScript can make an archived page incomplete. It prefers not to collect administration sections or other areas that were not intended for general access, and asks site owners to raise those scope concerns directly.

These captures support preservation and later research. The Library does not state that this crawler feeds AI search or trains general-purpose models. An archival request should not be counted as evidence that a page will appear in an AI response.

Indirectly relevant

Is Library Of Congress Web Archiving relevant for AI search?

Indirectly. Library Of Congress Web Archiving has no AI product of its own, but its output can end up in the systems that AI answers draw on.

Library Of Congress Web Archiving gathers pages for research corpora and web-measurement studies. Several widely used AI training datasets began as academic crawls, so pages collected for a study can later teach commercial models what your brand is.

How to handle Library Of Congress Web Archiving

Read the Library's notice or permission request before changing access. If you agree to collection, keep public pages and their supporting files reachable. Authentication should continue to protect administration routes and anything that was never meant for public viewing.

Do not depend on robots.txt to stop this program. The Library says its archival crawler is instructed to bypass exclusions. The recorded www.loc.gov value appears inside the site-owner information URL, not as a dependable standalone product token, so a User-agent: www.loc.gov snippet would give false confidence.

Ask the Web Archiving Program for its current user agents and source IPs when you need an allowlist or enforced block. Contact the program first if the issue is crawl frequency, load, or an overly broad seed. It can discuss collection changes without forcing the owner to block the entire archive capture.

Examples

An election campaign receives a selection notice. The site owner lets Heritrix capture public statements and page assets, while the volunteer database remains protected by login.
A monthly capture overwhelms an old media server that holds large images. The publisher gives the Library the affected timestamps and works with the program on a less disruptive collection.

Frequently asked questions about Library Of Congress Web Archiving

Learn about AI visibility monitoring and how Promptwatch helps your brand succeed in AI search.

Library subject experts choose seed URLs for preservation collections built around particular subjects or events. The selection may cover one page or a much larger part of the site.