What is Google-Extended?

What is Google-Extended?

Google-Extended is a dedicated user-agent Google uses to crawl websites for AI training purposes. Crucially, it's separate from Googlebot—blocking Google-Extended does not affect your Google Search rankings.

This separation gives website owners a unique choice: you can prevent your content from training Google's AI models while maintaining full Google Search visibility.

Google-Extended vs Googlebot

AspectGoogle-ExtendedGooglebot PurposeAI training dataSearch indexing Affects Search rankingsNoYes Affects AI OverviewsNoNo (uses Search index) Affects Gemini trainingYesNo Can block independentlyYesYes

Key insight: You can block Google-Extended while allowing Googlebot with no search penalty.

What Google-Extended Controls

Blocking Google-Extended prevents:

Your content training Gemini

Your content training Bard/other Google AI

Your content being used for AI product improvement

Blocking Google-Extended does NOT affect:

Google Search rankings

Google Search indexing

Google AI Overviews (uses Search index)

Any other Google services

Configuring robots.txt for Google-Extended

Block AI training only:

# Block AI training
User-agent: Google-Extended
Disallow: /
# Allow search indexing (implicit, but explicit is clearer)
User-agent: Googlebot
Allow: /

Allow everything (default if not specified):

User-agent: Google-Extended
Allow: /
User-agent: Googlebot
Allow: /

Partial blocking:

User-agent: Google-Extended
Disallow: /proprietary-content/
Disallow: /internal-docs/
Allow: /

AI Overviews Misconception

A common misconception: blocking Google-Extended will remove you from AI Overviews.

This is false.

Google AI Overviews uses the Google Search index (Googlebot), not Google-Extended crawls. Your content can appear in AI Overviews even if you block Google-Extended.

Google-Extended specifically controls training data for models like Gemini—not Search features.

When to Block Google-Extended

Consider blocking if:

You're concerned about AI training on proprietary content

You have original research you don't want replicated

Your business model depends on direct traffic

You're in industries with IP concerns (legal, creative, academic)

Consider allowing if:

You want maximum AI visibility

Brand awareness in AI responses matters

You're not concerned about training data usage

Competitors allowing Google-Extended would gain advantage

Google's Official Position

Google has stated:

Google-Extended is separate from Search functions

Blocking it has no negative Search consequences

It specifically controls AI training data access

The setting is respected and not circumvented

This is one of the clearer opt-out mechanisms in the AI ecosystem.

Google-Extended and Other AI Crawlers

Google-Extended only affects Google's AI training. You need separate rules for:

GPTBot (OpenAI/ChatGPT)

ClaudeBot (Anthropic/Claude)

PerplexityBot (Perplexity)

Each AI company operates independently. Blocking Google-Extended has no effect on other AI systems.

Verifying Google-Extended Activity

Check server logs:

grep "Google-Extended" /var/log/nginx/access.log

Or use Google Search Console to monitor crawl activity (though it combines all Google crawlers).

Strategic Considerations

The unique Google opportunity:

Unlike other AI providers, Google separates training from visibility. You can:

Appear in Google Search results ✓

Appear in AI Overviews ✓

Block AI training ✓

This isn't possible with most other AI systems where blocking the crawler removes you entirely.

Competitive dynamics:

If competitors allow Google-Extended and you don't, their content may influence Gemini's knowledge base more than yours. Consider whether this matters for your industry.

Common Mistakes

1. Thinking blocking affects Search

Google-Extended and Googlebot are independent. Blocking one doesn't affect the other.

2. Confusing Google-Extended with AI Overviews

AI Overviews uses Search index data, not Google-Extended crawls.

3. Blocking Googlebot to avoid AI

This would devastate your Search rankings. Only block Google-Extended.

4. Assuming one crawler setting covers all AI

Each AI company has separate crawlers requiring separate rules.

Summary

Google-Extended is Google's opt-out mechanism for AI training. It's unusual in allowing granular control: you can prevent your content from training Google's AI models while maintaining full Search visibility and AI Overview eligibility.

For most businesses, the decision comes down to priorities: maximum AI influence (allow) vs maximum control over training data (block).