ClaudeBot is the web crawler of Anthropic, the company behind the AI assistant Claude. It collects publicly available web content that Anthropic may use for training and developing its models. In server logs it appears with the user-agent token ClaudeBot.
At a glance
- Operator
- Anthropic
- Purpose
- Training (content that could contribute to model training)
- robots.txt token
ClaudeBot- Respects robots.txt
- yes, according to Anthropic; also
Crawl-delay
Last checked:
ClaudeBot should not be confused with “Clawdbot”, a separate AI assistant project with a similar name that dominates many search results for the term.
What does Anthropic use ClaudeBot for?
Anthropic runs three bots with separate tasks. ClaudeBot gathers content for model training. Claude-User fetches a website when a Claude user asks a question that requires it. Claude-SearchBot crawls the web to improve the quality of search results for users.
The split matters for site owners. Blocking ClaudeBot tells Anthropic that the site’s future content should be excluded from training data. Claude-User and Claude-SearchBot have their own user agents and need their own rules.
Cloudflare’s traffic data illustrates the difference between training and referral. For the first week of August 2025, Cloudflare reported a crawl-to-refer ratio of nearly 50,000 to 1 for Anthropic, meaning many crawled pages for each visit referred back to a site. This is a snapshot of one week, not a current value.
| Bot | Operator | Purpose | robots.txt token | robots.txt according to the operator | IP list published? |
|---|---|---|---|---|---|
| Google-Extended | Controls Gemini training and grounding (no crawler of its own) | Google-Extended | robots.txt token only; fetching is done by existing Google crawlers | n/a (no user agent of its own) | |
| GPTBot | OpenAI | Training | GPTBot | Disallowing it signals content should not be used to train foundation models | yes (openai.) |
| OAI-SearchBot | OpenAI | Search (ChatGPT) | OAI-SearchBot | opted-out sites are not shown in ChatGPT search answers | yes (openai.) |
| ChatGPT-User | OpenAI | User-triggered fetch | ChatGPT-User | robots.txt rules may not apply, says OpenAI (user-initiated) | yes (openai.) |
| ClaudeBot (this term) | Anthropic | Training | ClaudeBot | yes, Anthropic says its bots honor robots.txt | yes (claude.) |
| Claude-SearchBot | Anthropic | Search (Claude) | Claude-SearchBot | yes, Anthropic says its bots honor robots.txt | yes (claude.) |
| PerplexityBot | Perplexity | Search (Perplexity), not used for model training | PerplexityBot | controllable via robots.txt; the docs contain no explicit compliance statement | yes (perplexity.) |
| Applebot-Extended | Apple | Controls AI training (does not crawl, says Apple) | Applebot-Extended | robots.txt token only, applies to content Applebot already crawled | n/a (no crawler of its own) |
| CCBot | Common Crawl | Open web crawl archive | CCBot | can be blocked via robots.txt, says Common Crawl | yes (index.) |
| Meta-ExternalAgent | Meta | Training foundation AI models, improving products | meta-externalagent | can be blocked via robots.txt, says Meta | not stated by the operator |
A selection of ten AI bots from major operators, not a complete list. All values come from each operator's own documentation (as of 8 October 2026). The table does not show whether a bot actually complies with robots.txt; it only reflects what operators state. User agents can be spoofed; published IP lists or reverse DNS identify genuine requests. Sources: OpenAI: Overview of OpenAI Crawlers; Anthropic: Does Anthropic crawl data from the web, and how can site owners block the crawler? (updated 2026-04-07); Perplexity: Perplexity Crawlers; Google: Google's common crawlers (last updated 2026-07-14); Google: Overview of Google crawlers and fetchers (last updated 2026-06-12); Google: Verifying Google crawlers and fetchers (IP range files); Apple: About Applebot (2026-09-04); Meta: Meta Web Crawlers; Common Crawl: CCBot. Last checked: .
How do you control ClaudeBot?
Anthropic says it respects robots.txt directives and also supports the non-standard Crawl-delay extension to slow down crawling. The rules have to be set on every subdomain that should be covered.
To verify that a request really comes from Anthropic, check the source IP against the list Anthropic publishes at claude.com/crawling/bots.json. Anthropic advises against blocking its crawlers by IP address, because the bots then can’t read robots.txt, and the opt-out may not work reliably.
- The IETF publishes the Robots Exclusion Protocol as RFC 9309 on the Standards Track. It defines how crawlers interpret the rules in a robots.txt file.Source: rfc-editor.org
- OpenAI introduces web crawler permissions for AI. Site owners can use them to state whether their content may be used for AI training.Source: openai.com
- Google introduces Google-Extended. This robots.txt token controls whether content helps improve Bard and the Vertex AI generative APIs.Source: blog.google
- After Bard is renamed, Google's documentation lists Gemini Apps as a product affected by Google-Extended.Source: developers.google.com
- Apple introduces the foundation models behind Apple Intelligence. Publishers can opt out of training use, according to Apple's documentation via Applebot-Extended.Source: machinelearning.apple.com
- Cloudflare lets customers block AI bots, scrapers and crawlers with a single click.Source: blog.cloudflare.com
- With the SearchGPT prototype, OpenAI separates search from training. Sites can appear in search results even if they opt out of AI training.Source: openai.com
- Google adds Google-CloudVertexBot to its list of crawlers. It crawls sites at the owner's request to build Vertex AI Agents.Source: developers.google.com
- Based on publisher feedback, Google clarifies the description of the Google-Extended token.Source: developers.google.com
- Cloudflare proposes that bots and agents cryptographically sign their requests, based on HTTP Message Signatures (RFC 9421).Source: blog.cloudflare.com
- Cloudflare changes its default to block AI crawlers unless site owners decide otherwise.Source: blog.cloudflare.com
- Cloudflare launches pay per crawl as a private beta. Crawlers either pay per request or receive a 402 status code with a price.Source: blog.cloudflare.com
OpenAI only says “last summer” for its crawler permissions (post of May 7, 2024); the often-cited August 2023 date for GPTBot comes from press reports. ClaudeBot, Claude-SearchBot, Claude-User, PerplexityBot, Perplexity-User, OAI-SearchBot, ChatGPT-User, Meta-ExternalAgent and CCBot are documented by their operators, but without a verifiable launch date. Last checked: .
Example
Block ClaudeBot from the whole site while still allowing Claude-User:
User-agent: ClaudeBot
Disallow: /
User-agent: Claude-User
Allow: /
Slow ClaudeBot down instead of blocking it (delay in seconds):
User-agent: ClaudeBot
Crawl-delay: 1
Common mistakes
- Blocking only the main domain. Anthropic says the rule has to be set in robots.txt on every subdomain that should be opted out.
- Blocking ClaudeBot by IP address. Anthropic notes that the bot then cannot read robots.txt, so the opt-out may not work reliably.
- Treating ClaudeBot as all Anthropic bots. A ClaudeBot block concerns training. Claude-User and Claude-SearchBot have their own tokens and need their own rules.
- Trusting the user agent alone. It can be faked. Matching the source IP against Anthropic’s published list shows whether a request really comes from Anthropic.
FAQ
Should I block ClaudeBot? That depends on whether you want your content used to train AI models. A ClaudeBot block concerns training. Sites that want to be cited in Claude’s answers should look at Claude-User and Claude-SearchBot separately instead of blocking all Anthropic bots at once.
How do I find ClaudeBot in my log files?
Look for the token ClaudeBot in the user agent. Since that value can be faked, match the source IP against Anthropic’s published list as well.
More on the searchVIU blog
Sources
- Does Anthropic crawl data from the web, and how can site owners block the crawler? – Claude Help Center (updated 2026-04-07)support.claude.com
- IP ranges of Anthropic's crawlers (bots.json)claude.com
- A deeper look at AI crawlers: breaking down traffic by purpose and industry – Cloudflare Blog, 2025-08-28blog.cloudflare.com
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