AI crawler · Mistral · Fetches when a user asks

MistralAI-User: what it is, its user agent, and how to block it

MistralAI-User is Mistral's fetcher for user requests. Fetches a page when a Vibe user's question needs it, and links the source. In our 13 October 2026 study, 166 of 2,332 live top sites with readable robots.txt rules (7.1%) disallow MistralAI-User. Part of the AI crawler list.

What MistralAI-User does

Operator: Mistral. Job: Fetches when a user asks. Obeys robots.txt.

“`MistralAI-User` governs which sites these user requests can be made to. It is not used for crawling the web in any automatic fashion, nor to crawl content for generative AI training.”

Mistral's MistralAI-User documentation Published IP ranges (JSON)

MistralAI-User user agent

robots.txt token: MistralAI-User (matched case-insensitively).

Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; MistralAI-User/1.0; +https://docs.mistral.ai/robots)

robots.txt: allow or block MistralAI-User

Allow

User-agent: MistralAI-User
Allow: /

Block

User-agent: MistralAI-User
Disallow: /

Affects AI answers and citations. Blocking it refuses the fetch Mistral makes when a user asks its assistant to read your page.

Once a group names MistralAI-User, it ignores your User-agent: * rules, so copy any paths you still want blocked into it.

How many top sites block MistralAI-User

Disallow MistralAI-User in robots.txt

7.1%

166 of 2,332 sites

In our 13 October 2026 study, 166 of 2,332 live top sites with readable robots.txt rules (7.1%) disallow MistralAI-User.

Sample: Tranco top 5,000, tested once on 13 October 2026 from one Indian fixed-line connection. The robots.txt share counts live sites (home page 2xx) whose rules we could read, as on the AI visibility hub. Method and CSV in the study.

Check your own site

The AI crawler checker reads your robots.txt the way MistralAI-User does and tests what your firewall returns. To write the rules, use the AI robots.txt generator.

Check your page: free, about 20 seconds, no sign-in

What it checks

robots.txt for MistralAI-User: Finds the group MistralAI-User obeys under RFC 9309 and the rule that decides your page.
What your CDN lets through: Requests the page as OAI-SearchBot, PerplexityBot and Claude-SearchBot and compares the answers with a browser request.
Content without JavaScript: AI crawlers don't run JavaScript. The audit checks how much of the page is in the raw HTML.

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Questions

What is MistralAI-User?+

MistralAI-User is Mistral's fetcher for user requests. Fetches a page when a Vibe user's question needs it, and links the source.

What is MistralAI-User's user agent?+

Mistral documents it as: Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; MistralAI-User/1.0; +https://docs.mistral.ai/robots). Match on the token MistralAI-User, since version numbers change.

How do I block MistralAI-User?+

Add "User-agent: MistralAI-User" followed by "Disallow: /" to your robots.txt. Obeys robots.txt, per Mistral.

Does blocking MistralAI-User affect AI search citations?+

Blocking it refuses the fetch Mistral makes when a user asks its assistant to read your page.

How many websites block MistralAI-User?+