Does nejm.org block AI crawlers?
Blocks AI training and AI answers
nejm.org blocks both AI training crawlers and AI answer crawlers in its robots.txt.
Checked from nejm.org/robots.txt. Robots rules change; the live file is the source of truth.
- AI crawlers blocked
- 5 of 12
- AI bots named in robots.txt
- 5
- llms.txt
- Not found
- Popularity
- Tranco top 5,000 (#2,471)
Can AI assistants cite nejm.org?
- ChatGPT search: its search crawler is blocked
- Claude: its search crawlers may read the site
- Perplexity: its search crawler is blocked
nejm.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 nejm.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 | Blocked |
| 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 nejm.org compares
- 19% of the 1,278 popular sites we checked block GPTBot; nejm.org is one of them.
- 18% of the 1,278 popular sites we checked block ClaudeBot; nejm.org does not.
- 14% of the 1,278 popular sites we checked block PerplexityBot; nejm.org is one of them.
- Among 199 sites of similar popularity, 20% block at least one AI crawler.
The robots.txt rules that apply to AI crawlers
User-agent: * Disallow: /action Disallow: /help Disallow: /search Disallow: /feedback Disallow: /rss Disallow: /action/clickThrough Disallow: /action/showLogin Disallow: /page/account-confirmation-thanks Disallow: /media Disallow: /servlet/linkout Disallow: /author/ Disallow: /doi/mlt/ Allow: /action/showJournal Allow: /action/showPublications Allow: /action/showXml Allow: /media-center/ Allow: /series Allow: /isbn Allow: /doi/book User-agent: GPTBot Disallow: / User-agent: ChatGPT-User Disallow: / User-agent: CCBot Disallow: / User-agent: Google-Extended Disallow: / User-agent: PerplexityBot Disallow: /
Excerpt: only groups for all user-agents (*) or named AI crawlers, up to 40 rules per group.
Sites with a similar AI policy
Does nejm.org block GPTBot?
Yes. As of Oct 2, 2026, nejm.org's robots.txt disallows GPTBot, OpenAI's training crawler.
Can ChatGPT search show results from nejm.org?
Its robots.txt blocks a ChatGPT search crawler, so ChatGPT search is unlikely to read or cite those pages.
Does nejm.org have an llms.txt file?
We didn't find a valid llms.txt at nejm.org/llms.txt when we checked.
Data: nejm.org's public robots.txt and llms.txt, fetched by AskableHQ. Popularity rank from the Tranco list (ID Y83YG). Methodology.