What Is Google-Extended?
Google-Extended is a crawler user-agent introduced by Google in September 2023, designed specifically for AI-related data collection. It is separate from Googlebot (the primary search engine crawler) and is used to collect web content for training Google's AI models, including Gemini and the systems powering Google AI Overviews. By creating a distinct user-agent, Google gave website owners the ability to control AI training access independently from search engine indexing.
The name "Extended" reflects Google's framing: this crawler collects data for uses that extend beyond traditional search indexing. While Googlebot fetches content for Search ranking and indexing, Google-Extended fetches content for AI model improvement. This separation allows publishers to remain in Google Search results while opting out of AI training data collection — or vice versa.
Why Google-Extended Matters
Google-Extended occupies a unique position in the AI crawler landscape because of Google's dual role as both the dominant search engine and a major AI platform. Decisions about Google-Extended access have implications for Google AI Overviews, which appear at the top of billions of search queries and represent one of the highest-visibility AI surfaces in existence.
The relationship between Google-Extended and AI Overviews is nuanced. Google has stated that blocking Google-Extended does not prevent your content from appearing in AI Overviews, since those are powered by the regular search index. However, blocking Google-Extended may affect how Google's AI models are trained, which could indirectly influence the quality of AI-generated answers that reference your content in future model iterations. The exact dynamics remain somewhat opaque.
As of early 2026, approximately 15% of top websites block Google-Extended — a lower rate than GPTBot blocking, reflecting the concern many publishers have about losing Google Search visibility (even though blocking Google-Extended doesn't affect search rankings). This creates an interesting competitive dynamic: if your competitors block Google-Extended but you don't, your content may have a training data advantage in future Google AI model updates.
In Practice
Understand the separation: Blocking Google-Extended does NOT affect your Google Search rankings. Googlebot and Google-Extended are independent. You can block one without affecting the other. This is the most important technical fact to understand before making access decisions.
Consider AI Overviews strategy: If Google AI Overviews are a significant visibility channel for your brand, consider allowing Google-Extended to ensure your content is well-represented in the training data that powers these features. While the direct link is not confirmed, the indirect benefits of contributing to AI model training are plausible.
Monitor AI Overviews presence: Track whether your site appears in Google AI Overviews for your target queries. Changes in AI Overviews presence after modifying Google-Extended access can help you understand the practical impact of your crawler access decisions.
Stay updated on Google's policies: Google's AI crawler landscape is evolving. New user-agents and policy changes are introduced periodically. Maintain awareness of Google's crawling documentation and update your robots.txt as new AI-specific crawlers are announced.
How Presenc AI Helps
Presenc AI tracks your brand's visibility in Google AI Overviews alongside other AI platforms. The platform monitors whether your content appears in AI Overview panels, which queries trigger your inclusion, and how your AI Overviews presence changes over time. Presenc also audits your Google-Extended access configuration and helps you understand the visibility implications of your current settings, enabling informed decisions about Google's AI crawler access.