Googlebot

Both follow the same robots.txt token, Googlebot, so you can’t target one of them on its own.

For most sites, Google mainly indexes the mobile version, so most crawl requests come from the smartphone crawler.

The rule below keeps Googlebot out of a checkout folder, while the rest of the site stays crawlable. Remember that a robots.txt block stops crawling, not indexing: use noindex to keep a page out of results.

User-agent: Googlebot
Disallow: /checkout/

Google says AI is built into Search, which is why robots.txt rules for Googlebot are the control for how your site is crawled for Search, AI Overviews and AI Mode included.

Blocking Googlebot affects Google Search, including Discover and all Search features, as well as Google Images, Google Video and Google News.

• Don’t block Googlebot if you want to appear in Google’s AI features; there is no separate Google AI crawler to allow.
• Use nosnippet or max-snippet to limit what Google shows, AI Overviews included.
• Verify real Googlebot traffic before you block anything: Google warns its user agent is often spoofed.

Try it: Free robots.txt generator

Google-Extended

Google-Extended is not a crawler and doesn’t affect Search. It only controls Gemini training and grounding.