Rattlesnakes By Mail

Bingbot vs Claude-User

Bingbot and Claude-User compared on 12 documented fields, from 21 claims, last verified 2026-09-14.

Field	Bingbot	Claude-User	Comparison
cites_sources	yes	not_documented	different
follows_noarchive	yes	not documented	different
honours_crawl_delay	yes	yes	same
opt_out_mechanism	yes	not documented	different
publishes_ip_list	yes	yes	same
purpose_documented	yes	user_fetch	different
reads_llms_txt	not_documented	not_documented	same
respects_robots_txt	yes	yes	same
separate_search_and_training_tokens	no	not_documented	different
user_agent_string_full	Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm)	not_documented	different
user_fetch_exception_documented	not documented	no	different
verifiable_by_rdns	yes	not_documented	different

Differences

Field	Bingbot statement	Claude-User statement
cites_sources	Copilot Search in Bing delivers clearly cited sources alongside generative answers to support publishers and content owners.	Anthropic does not publish whether Claude responses cite pages fetched by Claude-User.
follows_noarchive	Bingbot excludes noarchive-tagged content from Copilot and Chat answers and from generative AI training data.	not documented
opt_out_mechanism	Microsoft lets publishers block Bingbot content from Copilot answers and AI training using noarchive and nocache tags.	not documented
purpose_documented	Bingbot serves as Microsoft's standard crawler and handles most of Bing's daily web crawling.	Claude-User accesses websites in response to questions that individual users ask Claude.
separate_search_and_training_tokens	Microsoft controls Bingbot's use in AI training through meta tags rather than publishing a separate training-specific crawler token.	Anthropic does not document Claude-User as a search or training opt-out token.
user_agent_string_full	Bingbot sends a user agent string containing bingbot/2.0 and a link to Microsoft's bingbot.htm page.	Anthropic does not publish a full user agent string for Claude-User.
user_fetch_exception_documented	not documented	Anthropic applies the same robots.txt statement to Claude-User as to ClaudeBot and Claude-SearchBot and documents no exception for user-initiated fetches.
verifiable_by_rdns	Microsoft verifies Bingbot traffic through reverse DNS lookups that resolve to hostnames ending in search.msn.com.	Anthropic does not publish a reverse-DNS verification method for Claude-User.

Sources