Meta-ExternalAgent vs Google-Extended: Which AI Crawler Should You Allow or Block?
Complete side-by-side comparison of Meta-ExternalAgent (Meta) and Google-Extended (Google): user-agent strings, safety ratings, SEO impact, and copy-paste blocking rules. Updated August 2026.
Quick Verdict
Both Meta-ExternalAgent and Google-Extended carry the same safety rating (Safe). Your decision should come down to whether you want your content used by Meta versus Google, and whether each bot's purpose (training, search, or user requests) aligns with your content strategy.
| Attribute | Meta-ExternalAgent | Google-Extended |
|---|---|---|
| Operator | Meta | |
| User-agent string | meta-externalagent |
Google-Extended |
| Category | AI & LLM Bots | AI & LLM Bots |
| Safety rating | Safe | Safe |
| SEO impact if blocked | Varies - Evaluate before blocking | Low - No SEO ranking impact |
| Recommendation | Generally safe to allow; provides legitimate crawling value. | Generally safe to allow; provides legitimate crawling value. |
| Official docs | Meta-ExternalAgent docs | Google-Extended docs |
What is Meta-ExternalAgent?
A generic user-agent used by Meta for external fetching tasks.
Full Meta-ExternalAgent guideWhat is Google-Extended?
A standalone token that allows web publishers to control whether their content is used to train Google's AI models (Gemini, Vertex AI) without affecting Google Search ranking.
Full Google-Extended guideHow to block each bot
Block Meta-ExternalAgent in robots.txt
User-agent: meta-externalagent Disallow: /
Block Google-Extended in robots.txt
User-agent: Google-Extended Disallow: /
Want to block or allow many bots at once? Use our free robots.txt generator with 196+ bot presets, then verify with the AI crawler checker.
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