- Anthropic's Claude AI chatbot shared chats were unexpectedly indexed by search engines like Google and Bing, exposing private conversations.
- The issue stems from a missing 'noindex' HTML tag on shared chat pages, which search engines recommend in addition to robots.txt directives.
- Anthropic's robots.txt file blocks crawlers from indexing shared chats, but this is insufficient if other sites link to those pages.
- Google and Bing both state that developers should use both robots.txt and a 'noindex' tag to prevent indexing, but Claude's shared pages lacked the tag.
- A similar problem occurred in September 2025, and Anthropic was criticized for not implementing proper controls.
- Shared chats no longer appear in Google results, but the pages still lack 'noindex' tags, risking future exposure.
- Users can manage their shared chats via Settings > Privacy > Shared chats to keep conversations private.