# Bingbot vs ClaudeBot

Bingbot and ClaudeBot compared on 16 documented fields, from 23 claims, last verified 2026-09-15.

| Field | Bingbot | ClaudeBot | Comparison |
| --- | --- | --- | --- |
| anti_circumvention_stance | not documented | documented | different |
| cites_sources | yes | not documented | different |
| follows_noarchive | yes | not documented | different |
| honours_crawl_delay | yes | yes | same |
| observed_fetches_json | not documented | yes | different |
| observed_fetches_markdown | not documented | yes | different |
| observed_first_request_path | not documented | /sitemap.xml | different |
| observed_format_pass_order | not documented | html_json_md | different |
| opt_out_mechanism | yes | not documented | different |
| publishes_ip_list | yes | yes | same |
| purpose_documented | yes | training | different |
| reads_llms_txt | not_documented | not documented | different |
| respects_robots_txt | yes | yes | same |
| separate_search_and_training_tokens | no | yes | different |
| user_agent_string_full | Mozilla/5.0 (compatible; bingbot/2.0; +http://www.bing.com/bingbot.htm) | not_documented | different |
| verifiable_by_rdns | yes | not_documented | different |

## Differences

| Field | Bingbot statement | ClaudeBot statement |
| --- | --- | --- |
| anti_circumvention_stance | not documented | ClaudeBot respects anti-circumvention technologies and does not bypass CAPTCHAs on crawled sites. |
| cites_sources | Copilot Search in Bing delivers clearly cited sources alongside generative answers to support publishers and content owners. | not documented |
| follows_noarchive | Bingbot excludes noarchive-tagged content from Copilot and Chat answers and from generative AI training data. | not documented |
| observed_fetches_json | not documented | ClaudeBot made 177 JSON requests to Rattlesnakes By Mail between 2026-09-13T20:00Z and 2026-09-15T09:00Z, covering the .json twin of 170 base paths. The .json URLs of Rattlesnakes By Mail appear in no entry of the 171 URL sitemap. |
| observed_fetches_markdown | not documented | ClaudeBot fetched the .md twin of 170 base paths on Rattlesnakes By Mail between 2026-09-13T20:00Z and 2026-09-15T09:00Z, 170 Markdown requests of 542 ClaudeBot requests in that window. The .md URLs of Rattlesnakes By Mail appear in no entry of the 171 URL sitemap. |
| observed_first_request_path | not documented | ClaudeBot's first request to Rattlesnakes By Mail between 2026-09-13T20:00Z and 2026-09-15T09:00Z was /sitemap.xml at 2026-09-14T19:53:45Z. ClaudeBot fetched /robots.txt on the second request to Rattlesnakes By Mail. |
| observed_format_pass_order | not documented | ClaudeBot fetched Rattlesnakes By Mail in three format passes between 2026-09-13T20:00Z and 2026-09-15T09:00Z, HTML from 2026-09-14T20:52Z to 2026-09-14T20:57Z, then JSON from 2026-09-14T21:37Z to 2026-09-14T21:56Z, then Markdown from 2026-09-14T21:37Z to 2026-09-14T21:57Z. The same order holds on 170 of 170 base paths that ClaudeBot fetched in all three formats on Rattlesnakes By Mail. |
| 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. | ClaudeBot collects web content for training Anthropic generative AI models. |
| reads_llms_txt | Microsoft does not publish whether Bingbot reads llms.txt files. | not documented |
| 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 separates training and search controls into two robots.txt tokens: ClaudeBot for training and Claude-SearchBot for search. |
| 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 ClaudeBot. |
| 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 ClaudeBot. |

## Sources

- https://blogs.bing.com/search/April-2025/Introducing-Copilot-Search-in-Bing
- https://claude.com/crawling/bots.json
- https://rattlesnakesbymail.com/observed/claudebot
- https://support.claude.com/en/articles/8896518-does-anthropic-crawl-content-from-the-web-and-how-can-site-owners-block-the-crawler
- https://www.bing.com/toolbox/bingbot.json
- https://www.bing.com/webmasters/help/ai-performance-9f8e7d6c
- https://www.bing.com/webmasters/help/crawl-control-55a30303
- https://www.bing.com/webmasters/help/how-to-verify-bingbot-3905dc26
- https://www.bing.com/webmasters/help/robots-meta-tags-and-attributes-that-bing-supports-5198d240
- https://www.bing.com/webmasters/help/which-crawlers-does-bing-use-8c184ec0