Google-Extended

Google-Extended is a separate access control token introduced by Google so publishers can keep their content in Google Search while opting out of generative AI training and grounding.

Key behavior

Unlike most user agents, Google-Extended is not a crawler. It is a signal that controls how content already fetched by Googlebot may be used by Google's AI products such as Gemini and Google AI Mode.

Allow vs block

# Block AI training and AI grounding, keep classic Search indexing
User-agent: Google-Extended
Disallow: /

# Allow Google AI products to use your content
User-agent: Google-Extended
Allow: /

Trade-off

Blocking Google-Extended preserves long-term content control, but it also removes your pages from Google's generative answers — including AI Overviews and AI Mode. For most brands that depend on organic visibility, the cost of opting out is higher than the cost of being trained on.

How it fits with other Google bots

• Googlebot — classic search crawler (still required for Search rankings)
• Google-Extended — AI training and AI surface grounding control
• GoogleOther — research and product development crawlers

These are controlled independently.