Google-Extended (Google)
Model training
What it is
Google-Extended is not a separate crawler but a robots.txt token. It controls whether content Google crawls from your site may be used to train future Gemini models and for grounding in Gemini Apps and Grounding with Google Search on Vertex AI. Google says it does not affect inclusion in Google Search and is not a ranking signal.
Official documentation: developers.google.com · checked 13 Nov 2026
Google-Extended user agent
Google-Extended has no user agent string of its own: it never visits your site. It exists only as a token for the User-agent line of robots.txt.
Official documentation: developers.google.com/crawling/docs/crawlers-fetchers/google-common-crawlers · checked 13 Nov 2026
Block or allow Google-Extended in robots.txt
Put these lines at the top of the robots.txt file in your site’s root (example.com/robots.txt). Each subdomain needs its own file.
User-agent: Google-Extended
Disallow: /
User-agent: Google-Extended
Allow: /
# repeat here the Disallow lines of your User-agent: * group
If Google-Extended is not named in robots.txt, it already follows your User-agent: * rules, so you don’t need anything. A group of its own replaces the * group for this bot entirely: if you add one, repeat your general Disallow lines in it.
Google-Extended IP ranges
Google-Extended has no crawler and no IP addresses of its own: Google crawls with its usual crawlers and uses this token only to decide how the content may be used. Their addresses are on the Googlebot page. Googlebot
Does it respect robots.txt and Crawl-delay?
robots.txt: Google-Extended is itself a robots.txt token. It does not crawl, so a rule for it tells the owner how content collected by its other crawlers may be used.
“the robots.txt user-agent token is used in a control capacity.” — Google documentation
Crawl-delay: not supported for Google-Extended.
“other fields such as crawl-delay aren't supported” — Google documentation
Should you block Google-Extended?
It is a legitimate choice. Blocking Google-Extended opts your content out of this kind of use, and search and AI answers that rely on other bots are not affected. If you want your content used by AI models, leave it open.
Check your site
See whether your robots.txt and firewall let Google-Extended in — together with every other AI bot in this directory. Free, no sign-up.
Other Google bots
Questions
What is the Google-Extended user agent string?+
Google does not publish a full user agent string for Google-Extended. Match the token “Google-Extended” instead.
How do I block Google-Extended in robots.txt?+
Add a group for it to robots.txt in your site’s root: “User-agent: Google-Extended” followed by “Disallow: /”.
Does Google-Extended respect robots.txt?+
robots.txt: Google-Extended is itself a robots.txt token. It does not crawl, so a rule for it tells the owner how content collected by its other crawlers may be used.