Which health publishers
block AI crawlers?
Medical reference sites, where being the cited source carries the highest stakes. 88 domains measured; 28 block at least one of the 30 tracked AI crawlers.
28of 88 health publishers block at least one AI crawler · median access 100%
The AI crawlers these sites block most
CCBot is blocked most often here, by 26 of 88 sites. What blocking each one means is in the AI crawler directory.
| User-agent | Operator | Purpose | Sites blocking |
|---|---|---|---|
CCBot | Common Crawl | training dataset | 26 of 88 |
ClaudeBot | Anthropic | model training | 22 of 88 |
Bytespider | ByteDance | model training | 21 of 88 |
Amazonbot | Amazon | model training | 20 of 88 |
Meta-ExternalAgent | Meta | model training | 18 of 88 |
Google-Extended | Gemini training control | 17 of 88 | |
GPTBot | OpenAI | model training | 17 of 88 |
Applebot-Extended | Apple | Apple Intelligence control | 16 of 88 |
Every domain in this category
Sorted by the share of tracked AI crawlers permitted, lowest first. Each report shows all 30 verdicts and the robots.txt rule behind them.
Method and caveats are described on the full study page: one robots.txt fetch per domain, resolved against 30 published AI user-agents, reported as the voluntary policy it is.