What is Google-Extended?
Google-Extended is Google's AI training crawler. Controls whether Google may train Gemini on your content. Blocking it does NOT affect Google Search or AI Overviews.
What does Google-Extended do with your content?
Controls whether Google may train Gemini on your content. Blocking it does NOT affect Google Search or AI Overviews. Like most AI crawlers, Google-Extended reads your pages as plain HTML — it does not run JavaScript — so content that only appears after scripts execute is invisible to it.
Should you block Google-Extended?
Blocking Google-Extended only opts your content out of Gemini model training. It does NOT remove you from Google Search or from AI Overviews — both of those run on Googlebot. If your goal is staying visible in Google while opting out of model training, blocking Google-Extended is a reasonable, low-risk choice.
How do you allow or block Google-Extended in robots.txt?
Add one of these snippets to the robots.txt file at the root of your site. The first explicitly allows Google-Extended everywhere; the second blocks it completely.
# Allow Google-Extended
User-agent: Google-Extended
Allow: /
# Block Google-Extended
User-agent: Google-Extended
Disallow: /Is robots.txt enough?
Not always. CDNs and firewalls (Cloudflare in particular) can block crawlers at the network level regardless of what robots.txt says — Cloudflare blocks AI crawlers by default for many accounts. If you want Google-Extended to reach your site, check your CDN's bot settings too. SeeGeo's free audit checks both.
How do I check whether Google-Extended can read my site right now?
Two checks, both needed: read your robots.txt for a group naming Google-Extended (or the * group it falls back to), then request your homepage with Google-Extended's user agent and confirm you get a 200 with your real HTML rather than a 403 or a challenge page. SeeGeo's free crawler check runs both in a few seconds.
How does Google-Extended compare to similar crawlers?
Google-Extended is one of 16 crawlers the SeeGeo audit checks individually. The closest comparisons:
| Crawler | Operator | Role | Runs JavaScript? |
|---|---|---|---|
| Google-Extended | AI training crawler | No | |
| Googlebot | search engine crawler | Delayed rendering | |
| GPTBot | OpenAI | AI training crawler | No |
| ClaudeBot | Anthropic | AI training crawler | No |
| CCBot | Common Crawl | AI training crawler | No |
Why does crawler access matter? The numbers
Crawler access is where AI visibility starts or ends: a blocked crawler can't read you, and an AI that can't read you can't recommend you.
- Visitors arriving from AI assistants convert at roughly 4.4x the rate of traditional organic search on average (Semrush, cross-industry, 2026).
- AI-assistant referrals are still only about 1% of total web traffic — small, but the fastest-growing acquisition channel measured (multiple 2026 studies).
- Adobe Digital Insights (Q1 2026) measured AI-assistant visitors converting 42% better than non-AI traffic — a full reversal from the year before.
- Cloudflare blocks AI crawlers by default for many accounts, so sites are often invisible to AI without anyone having decided to be.
- Content edits alone — statistics, citations, quotable structure — can raise AI visibility on the order of 30–40% (Princeton GEO study, KDD 2024).
Frequently asked questions
What is Google-Extended?
Google-Extended is Google's AI training crawler. Controls whether Google may train Gemini on your content. Blocking it does NOT affect Google Search or AI Overviews.
Should I block Google-Extended?
Blocking Google-Extended only opts your content out of Gemini model training. It does NOT remove you from Google Search or from AI Overviews — both of those run on Googlebot.
Does Google-Extended run JavaScript?
No. Google-Extended, like most AI crawlers, reads raw HTML without executing JavaScript. If your content only renders client-side, it is effectively invisible to it.
Can Google-Extended read my website?
Only if two things are true: your robots.txt does not disallow Google-Extended, and your server or CDN actually serves the page when Google-Extended asks. Firewalls can block it regardless of robots.txt, so the reliable way to know is to fetch your homepage as Google-Extended — the free check on see-geo.com/ai-crawler-check does exactly that.
Does blocking Google-Extended affect Google Search rankings?
No. Google-Extended only controls Gemini model training. Google Search and AI Overviews use Googlebot, so blocking Google-Extended has no effect on either.