What is Claude-User?
Claude-User is Anthropic's on-demand AI fetcher. Fetches your page live during a Claude conversation.
What does Claude-User do with your content?
Fetches your page live during a Claude conversation. Like most AI crawlers, Claude-User reads your pages as plain HTML — it does not run JavaScript — so content that only appears after scripts execute is invisible to it.
Should you block Claude-User?
Blocking Claude-User makes your business invisible to Anthropic's AI when customers ask it for recommendations. If you want to be found, allow it; block it only if you have a specific reason to keep Anthropic's AI away from your content.
How do you allow or block Claude-User in robots.txt?
Add one of these snippets to the robots.txt file at the root of your site. The first explicitly allows Claude-User everywhere; the second blocks it completely.
# Allow Claude-User
User-agent: Claude-User
Allow: /
# Block Claude-User
User-agent: Claude-User
Disallow: /Is robots.txt enough?
Not always. CDNs and firewalls (Cloudflare in particular) can block crawlers at the network level regardless of what robots.txt says — Cloudflare blocks AI crawlers by default for many accounts. If you want Claude-User to reach your site, check your CDN's bot settings too. SeeGeo's free audit checks both.
How do I check whether Claude-User can read my site right now?
Two checks, both needed: read your robots.txt for a group naming Claude-User (or the * group it falls back to), then request your homepage with Claude-User's user agent and confirm you get a 200 with your real HTML rather than a 403 or a challenge page. SeeGeo's free crawler check runs both in a few seconds.
How does Claude-User compare to similar crawlers?
Claude-User is one of 16 crawlers the SeeGeo audit checks individually. The closest comparisons:
| Crawler | Operator | Role | Runs JavaScript? |
|---|---|---|---|
| Claude-User | Anthropic | on-demand AI fetcher | No |
| ClaudeBot | Anthropic | AI training crawler | No |
| ChatGPT-User | OpenAI | on-demand AI fetcher | No |
| Perplexity-User | Perplexity | on-demand AI fetcher | No |
Why does crawler access matter? The numbers
Crawler access is where AI visibility starts or ends: a blocked crawler can't read you, and an AI that can't read you can't recommend you.
- Visitors arriving from AI assistants convert at roughly 4.4x the rate of traditional organic search on average (Semrush, cross-industry, 2026).
- AI-assistant referrals are still only about 1% of total web traffic — small, but the fastest-growing acquisition channel measured (multiple 2026 studies).
- Adobe Digital Insights (Q1 2026) measured AI-assistant visitors converting 42% better than non-AI traffic — a full reversal from the year before.
- Cloudflare blocks AI crawlers by default for many accounts, so sites are often invisible to AI without anyone having decided to be.
- Content edits alone — statistics, citations, quotable structure — can raise AI visibility on the order of 30–40% (Princeton GEO study, KDD 2024).
Frequently asked questions
What is Claude-User?
Claude-User is Anthropic's on-demand AI fetcher. Fetches your page live during a Claude conversation.
Should I block Claude-User?
Blocking Claude-User makes your business invisible to Anthropic's AI when customers ask it for recommendations. If you want to be found, allow it; block it only if you have a specific reason to keep Anthropic's AI away from your content..
Does Claude-User run JavaScript?
No. Claude-User, like most AI crawlers, reads raw HTML without executing JavaScript. If your content only renders client-side, it is effectively invisible to it.
Can Claude-User read my website?
Only if two things are true: your robots.txt does not disallow Claude-User, and your server or CDN actually serves the page when Claude-User asks. Firewalls can block it regardless of robots.txt, so the reliable way to know is to fetch your homepage as Claude-User — the free check on see-geo.com/ai-crawler-check does exactly that.