Does worldcat.org block AI crawlers?
Blocks AI training and AI answers
worldcat.org blocks both AI training crawlers and AI answer crawlers in its robots.txt.
Checked from worldcat.org/robots.txt. Robots rules change; the live file is the source of truth.
- AI crawlers blocked
- 4 of 12
- AI bots named in robots.txt
- 4
- llms.txt
- Not found
- Popularity
- Tranco top 5,000 (#3,288)
Can AI assistants cite worldcat.org?
- ChatGPT search: its search crawler is blocked
- Claude: its search crawlers may read the site
- Perplexity: its search crawlers may read the site
worldcat.org opts out of AI training by OpenAI, Google, Common Crawl. Training crawlers and answer crawlers are separate: blocking training doesn't by itself remove a site from AI answers.
AI crawler access, bot by bot
| Crawler | Used for | Status on worldcat.org |
|---|---|---|
| GPTBotOpenAI | AI training | Blocked |
| OAI-SearchBotOpenAI | AI answers | Some paths restricted |
| ChatGPT-UserOpenAI | AI answers | Blocked |
| ClaudeBotAnthropic | AI training | Some paths restricted |
| Claude-SearchBotAnthropic | AI answers | Some paths restricted |
| Claude-UserAnthropic | AI answers | Some paths restricted |
| PerplexityBotPerplexity | AI answers | Some paths restricted |
| Google-ExtendedGoogle | AI training | Blocked |
| Applebot-ExtendedApple | AI training | Some paths restricted |
| CCBotCommon Crawl | AI training | Blocked |
| BytespiderByteDance | AI training | Some paths restricted |
| Meta-ExternalAgentMeta | AI training | Some paths restricted |
How worldcat.org compares
- 19% of the 1,278 popular sites we checked block GPTBot; worldcat.org is one of them.
- 18% of the 1,278 popular sites we checked block ClaudeBot; worldcat.org does not.
- 14% of the 1,278 popular sites we checked block PerplexityBot; worldcat.org does not.
- Among 169 sites of similar popularity, 24% block at least one AI crawler.
The robots.txt rules that apply to AI crawlers
User-agent: GPTBot Disallow: / User-agent: ChatGPT-User Disallow: / User-agent: Google-Extended Disallow: / User-agent: CCBot Disallow: / User-agent: * Disallow: /search Disallow: /libraries/search Disallow: /lists/search Disallow: /user/account Disallow: /user/lists Disallow: /user/libraries Disallow: /libraries Disallow: /arcviewer Disallow: /registry Disallow: /formats-editions/* Disallow: /search?q=* Disallow: /libraries/search?q=* Disallow: /lists/search?q=*
Excerpt: only groups for all user-agents (*) or named AI crawlers, up to 40 rules per group.
Sites with a similar AI policy
Does worldcat.org block GPTBot?
Yes. As of Oct 2, 2026, worldcat.org's robots.txt disallows GPTBot, OpenAI's training crawler.
Can ChatGPT search show results from worldcat.org?
Its robots.txt blocks a ChatGPT search crawler, so ChatGPT search is unlikely to read or cite those pages.
Does worldcat.org have an llms.txt file?
We didn't find a valid llms.txt at worldcat.org/llms.txt when we checked.
Data: worldcat.org's public robots.txt and llms.txt, fetched by AskableHQ. Popularity rank from the Tranco list (ID Y83YG). Methodology.