AI crawler · Mistral · AI search index

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

MistralAI-Index is Mistral's AI search crawler. Builds Mistral's search index, which helps answer questions in its Vibe assistant. Not used for training. In our 13 October 2026 study, 95 of 2,332 live top sites with readable robots.txt rules (4.1%) disallow MistralAI-Index. Part of the AI crawler list.

What MistralAI-Index does

Operator: Mistral. Job: AI search index. Obeys robots.txt.

“To help webmasters manage how their sites and content interact with AI, Mistral uses specific `robots.txt` tags.”

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

MistralAI-Index user agent

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

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

robots.txt: allow or block MistralAI-Index

Allow

User-agent: MistralAI-Index
Allow: /

Block

User-agent: MistralAI-Index
Disallow: /

Affects AI answers and citations. Blocking it keeps your pages out of the index Mistral's AI search answers cite. It is not a training crawler.

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

How many top sites block MistralAI-Index

Disallow MistralAI-Index in robots.txt

4.1%

95 of 2,332 sites

In our 13 October 2026 study, 95 of 2,332 live top sites with readable robots.txt rules (4.1%) disallow MistralAI-Index.

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-Index 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-Index: Finds the group MistralAI-Index 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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$9 / ₹499 once

Every issue with its exact fix for one site, PDF/Markdown/JSON exports, re-audit for 30 days. Nothing renews.

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Questions

What is MistralAI-Index?+

MistralAI-Index is Mistral's AI search crawler. Builds Mistral's search index, which helps answer questions in its Vibe assistant. Not used for training.

What is MistralAI-Index's user agent?+

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

How do I block MistralAI-Index?+

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

Does blocking MistralAI-Index affect AI search citations?+

Blocking it keeps your pages out of the index Mistral's AI search answers cite. It is not a training crawler.

How many websites block MistralAI-Index?+