User-triggered fetcherGoogle reviewed September 2026

Google-Agent

Google operates Google-Agent, a user-triggered fetcher that agents hosted on Google infrastructure use to navigate the web and perform actions at a user's request. Google lists it among fetchers that generally ignore robots.txt and documents no robots.txt token. Site owners verify requests against the published user-triggered-agents.json IP ranges and DNS; some requests also carry a Web Bot Auth signature.

OperatorGoogle
User-agent tokenGoogle-Agent
PurposeUser-triggered fetcher
robots.txt tokenundocumented
Honors robots.txtNo, per the operator
Published IP rangesYes, 20 prefixes (12 IPv4, 8 IPv6)
VerificationMatch the source IP against user-triggered-agents.json (the docs say 'It uses IP ranges from user-triggered-agents.json'), together with the general reverse and forward DNS check. A subset of Google-Agent requests also carry an experimental Web Bot Auth signature: Signature-Agent: g="https://agent.bot.goog", signed per RFC 9421 HTTP Message Signatures, with public keys at https://agent.bot.goog/.well-known/http-message-signatures-directory. Google says not all requests are signed and to fall back to IP-based verification.
Reverse DNS suffixundocumented for agents specifically; the user-triggered fetchers page gives ***-***-***-***.gae.googleusercontent.com or google-proxy-***-***-***-***.google.com for the category
Full user-agent example (from the operator)Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko; compatible; Google-Agent; +https://developers.google.com/crawling/docs/crawlers-fetchers/google-agent) Chrome/W.X.Y.Z Safari/537.36

What Google-Agent does

Requests arrive with a Chrome-like user agent that includes the compatible; Google-Agent token and a link to the Google-Agent documentation, which redirects to the user-triggered fetchers page. A mobile variant with an Android Nexus 5X string exists as well. Google says the fetch happens because a user asked an agent hosted on Google infrastructure to navigate to the page or perform an action there. The 2026-03-20 changelog entry announced the user agent as rolling out over the following weeks, and the 2026-05-04 entry added the Web Bot Auth documentation.

Google classes it as a user-triggered fetcher, and it says such fetchers generally ignore robots.txt rules because a user requested the fetch. No robots.txt token is documented, so a Disallow line is not a documented control. Site owners who want to limit it can act at the request level, by matching the source IP against Google's published ranges and deciding per request. Allowing it lets user-directed agents on Google infrastructure read and act on the site; blocking it stops those agent sessions from reaching the site.

Google publishes the ranges in user-triggered-agents.json at the /static/crawling/ipranges/ path. Under the experimental Web Bot Auth scheme, a subset of requests carry a Signature-Agent header of g="https://agent.bot.goog" and an RFC 9421 HTTP Message Signature, with public keys at https://agent.bot.goog/.well-known/http-message-signatures-directory. Google says not all requests are signed and to fall back to IP-based verification.

Operator note. Listed under user-triggered fetchers, which 'generally ignore robots.txt rules' because the fetch was requested by a user; no robots.txt token is documented. Mobile UA: 'Mozilla/5.0 (Linux; Android 6.0.1; Nexus 5X Build/MMB29P) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/W.X.Y.Z Mobile Safari/537.36 (compatible; Google-Agent; +https://developers.google.com/crawling/docs/crawlers-fetchers/google-agent)'. Changelog 2026-03-20: 'Added the Google-Agent user agent ... rolling out over the next few weeks.'; changelog 2026-05-04 added the Web Bot Auth documentation. The user-triggered-agents.json range file is published under the /static/crawling/ipranges/ path; use that rather than the older /static/search/apis/ipranges/ location.

Controlling Google-Agent with robots.txt

Use the token undocumented in robots.txt. Google documents that this fetcher does not consult robots.txt, so a robots rule will not stop it; see the operator note.

Block everything
User-agent: undocumented
Disallow: /
Allow everything
User-agent: undocumented
Allow: /

Verifying a request is really Google-Agent

Anyone can put Google-Agent in a User-Agent header. Match the source IP against user-triggered-agents.json (the docs say 'It uses IP ranges from user-triggered-agents.json'), together with the general reverse and forward DNS check. A subset of Google-Agent requests also carry an experimental Web Bot Auth signature: Signature-Agent: g="https://agent.bot.goog", signed per RFC 9421 HTTP Message Signatures, with public keys at https://agent.bot.goog/.well-known/http-message-signatures-directory. Google says not all requests are signed and to fall back to IP-based verification.

Reverse DNS check
host <request-ip>
# expect a hostname ending in undocumented for agents specifically; the user-triggered fetchers page gives ***-***-***-***.gae.googleusercontent.com or google-proxy-***-***-***-***.google.com for the category
host <that-hostname>
# expect it to resolve back to <request-ip>
Published IP ranges

Google publishes a machine-readable list. Our probe read it on 2026-09-06; the file's own creation time was 2026-09-03.

Open the live file
Prefixes
20
IPv4
12
IPv6
8

First entries at fetch time: 2001:4860:c::/124, 2001:4860:c::10/124, 2001:4860:c::20/124

SHA-256 of the fetched body: 4a9f1b91c8b1e0c25fb62411dbd496746a37c41713b1d97ce9e2edf629a04b6a

Common questions

Does Google-Agent obey robots.txt?

Google says no in general. It lists Google-Agent under user-triggered fetchers, which generally ignore robots.txt rules because a user requested the fetch, and it documents no robots.txt token for the agent. Control has to happen at the request level using the published IP ranges.

How do I verify Google-Agent?

Match the source IP against https://developers.google.com/static/crawling/ipranges/user-triggered-agents.json and run Google's reverse and forward DNS check. Google documents no reverse-DNS suffix for Google-Agent itself; for the user-triggered fetcher category it gives hostnames under gae.googleusercontent.com or google-proxy-...google.com. A subset of requests carry an RFC 9421 signature for https://agent.bot.goog, but Google says to fall back to IP checks because not every request is signed.

Does Google-Agent run JavaScript?

The operator's documentation does not say. The user agent string is Chrome-like, which describes the string only; Google's documentation gives no statement about rendering or script execution for Google-Agent.

Sources

Every fact on this page was checked against Google's own documentation, listed below, and re-checked by a second reviewer before publication. Reviewed September 2026.

Related crawlers

Google-Extended
Google · AI training crawler
Google-CloudVertexBot
Google · AI search index
Chrome Web Store
Google · User-triggered fetcher
Feedfetcher
Google · User-triggered fetcher
Gemini Notebook
Google · User-triggered fetcher
Google Pinpoint
Google · User-triggered fetcher

This registry documents how operators describe their own bots so site owners can identify and control them. It does not publish third-party IP lists or guess at undocumented behaviour. To see how your own site responds to automated visitors, the bot detection scanner reads a URL's live response and names the protection it finds.