AdsBot Mobile Web
Google operates AdsBot Mobile Web, a special-case crawler with the token AdsBot-Google-Mobile that checks web page ad quality for Google Ads. It honors robots.txt only partially; rules addressed to its own token apply, but the global User-agent: * group is ignored. Site owners verify it by reverse DNS to a rate-limited-proxy host under google.com with forward confirmation, or against special-crawlers.json.
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; AdsBot-Google-Mobile; +http://www.google.com/mobile/adsbot.html)What AdsBot Mobile Web does
The crawler identifies itself with an Android Chrome browser string ending in "(compatible; AdsBot-Google-Mobile; +http://www.google.com/mobile/adsbot.html)". Google lists it among its special-case crawlers. Its documented purpose is narrow. Crawling preferences addressed to AdsBot-Google-Mobile affect Google Ads' ability to check the quality of web pages, and Google says nothing about any other use of the fetched content. An older iPhone-UA variant carrying the same token is listed as retired, so the Android string is the one Google currently documents.
This crawler honors robots.txt only in part. A rule group whose User-agent line names AdsBot-Google-Mobile is respected, but the global User-agent: * group is ignored. A site that blocks all crawlers with a wildcard rule will still receive AdsBot-Google-Mobile visits unless it adds a group for that token. Blocking the token limits Google Ads' ability to check ad quality on the site's pages, per Google's wording; allowing it keeps those checks working.
Requests come through Google's rate-limited proxy addresses. To verify one, reverse-resolve the IP, confirm the hostname takes the form rate-limited-proxy-***-***-***-***.google.com, then forward-resolve that hostname and check it returns the same IP. Google also publishes special-crawlers.json, a list of prefixes shared by its special-case crawlers, which can be matched against the requesting address instead of running DNS lookups. Google does not document whether this crawler executes JavaScript.
Operator note. Special-case crawler; 'The global user agent (*) is ignored.' An older iPhone-UA variant with the same token is listed as retired.
Controlling AdsBot Mobile Web with robots.txt
Use the token AdsBot-Google-Mobile in robots.txt. Google documents limits on how this bot applies robots.txt; see the operator note.
User-agent: AdsBot-Google-Mobile
Disallow: /User-agent: AdsBot-Google-Mobile
Allow: /Verifying a request is really AdsBot Mobile Web
Anyone can put AdsBot-Google-Mobile in a User-Agent header. Reverse DNS to rate-limited-proxy-***-***-***-***.google.com with matching forward DNS, or match the source IP against special-crawlers.json.
host <request-ip>
# expect a hostname ending in google.com (rate-limited-proxy-***-***-***-***.google.com)
host <that-hostname>
# expect it to resolve back to <request-ip>Google publishes a machine-readable list. Our probe read it on 2026-09-06; the file's own creation time was 2026-09-04.
- Prefixes
- 272
- IPv4
- 136
- IPv6
- 136
First entries at fetch time: 2001:4860:4801:2008::/64, 2001:4860:4801:200c::/64, 2001:4860:4801:200d::/64
SHA-256 of the fetched body: 9da99f8a169f35bc80153ec102d0be5674975861f3705614ef6ae51fd32ea5a1
Common questions
Should I block AdsBot-Google-Mobile?
Blocking the token affects Google Ads' ability to check web page ad quality, which is the only purpose Google documents for it. Whether that concerns you depends on whether your pages are used in Google Ads. A User-agent: * Disallow does not apply to this crawler; you must name AdsBot-Google-Mobile directly.
Why does AdsBot-Google-Mobile ignore my robots.txt?
Google states that for this special-case crawler "the global user agent (*) is ignored." Only a rule group that names AdsBot-Google-Mobile in its User-agent line takes effect. Add that group with the paths you want restricted, and the crawler will follow it.
How do I verify AdsBot-Google-Mobile?
Reverse-resolve the requesting IP; the hostname should look like rate-limited-proxy-***-***-***-***.google.com. Forward-resolve that hostname and confirm it returns the same IP. Alternatively match the IP against the prefixes in Google's special-crawlers.json at https://developers.google.com/static/crawling/ipranges/special-crawlers.json.
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
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.