Google · Training

What is Google-Extended?

A control token, not a crawler: Googlebot does the fetching, and Google-Extended decides whether that content may be used for Gemini training and grounding.

robots.txt token: Google-Extended
Operator: Google
Purpose: Training
Obeys robots.txt: Yes The operator says it follows robots.txt.
Documented by operator: Yes, on the operator's own pages.
Documentation: developers.google.com

It has no user agent of its own, so it never appears in your access logs.

Block Google-Extended from your whole site

robots.txt

User-agent: Google-Extended
Disallow: /

Allow it, but keep private paths out

robots.txt

User-agent: Google-Extended
Allow: /
Disallow: /admin/

Other bots from Google

Googlebot Google-CloudVertexBot GoogleOther Google-Agent Google-GeminiNotebook Gemini Spark Gemini-Deep-Research GoogleAgent-Mariner

Add it to a robots.txt in the generator →

Sources

developers.google.com/search/docs/crawling-indexing/google-common-crawlers