Google Read Aloud
Google operates Google Read Aloud, a user-triggered fetcher that fetches and reads out web pages with text-to-speech when a user asks. Google documents no robots.txt token for it and says it generally ignores robots.txt. Site owners verify requests by reverse DNS to gae.googleusercontent.com or google.com with a matching forward lookup, or against the published user-triggered-fetchers-google.json IP ranges.
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36 (compatible; Google-Read-Aloud; +https://support.google.com/webmasters/answer/1061943)What Google Read Aloud does
A Read Aloud request appears in logs with a desktop user agent string ending in (compatible; Google-Read-Aloud; +https://support.google.com/webmasters/answer/1061943), or a mobile variant that begins Mozilla/5.0 (Linux; Android 10; K) and carries the same Google-Read-Aloud token. Google says each fetch happens because a user asked for the page to be read out through text-to-speech, which is why Google classes it as a user-triggered fetcher. Google lists the former google-speakr agent as deprecated, so that name no longer identifies the fetcher.
Because the fetch is user-triggered, robots.txt rules do not control it. Google states that user-triggered fetchers generally ignore robots.txt, and no dedicated robots token is documented. A site that wants to stop Read Aloud fetches has to act at the server level, for example by refusing requests from the published IP ranges or the Google-Read-Aloud user agent. Blocking removes the ability of a user to have your page read aloud through this feature. Google documents no effect on search indexing either way; it describes the purpose only as reading pages aloud on request.
Google's changelog entry of 2025-12-02 notes that the Read Aloud page now states the fetcher uses stateless rendering and needs to access the page to see its meta tags. A server-side block therefore stops it before it reaches those tags. For verification, the reverse DNS hostname takes the form ***-***-***-***.gae.googleusercontent.com or google-proxy-***-***-***-***.google.com, and the forward lookup of that hostname must return the same IP. As an alternative, match the IP against the prefixes in user-triggered-fetchers-google.json under developers.google.com/static/crawling/ipranges/.
Operator note. User-triggered fetcher; generally ignores robots.txt. Mobile UA: 'Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Mobile Safari/537.36 (compatible; Google-Read-Aloud; +https://support.google.com/webmasters/answer/1061943)'. The former agent 'google-speakr' is deprecated. Changelog 2025-12-02: the Read Aloud page was updated to note that it uses stateless rendering and needs to access the page to see its meta tags.
Controlling Google Read Aloud 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.
User-agent: undocumented
Disallow: /User-agent: undocumented
Allow: /Verifying a request is really Google Read Aloud
Anyone can put Google-Read-Aloud in a User-Agent header. Reverse DNS with matching forward DNS, or match the source IP against user-triggered-fetchers.json or user-triggered-fetchers-google.json.
host <request-ip>
# expect a hostname ending in gae.googleusercontent.com (***-***-***-***.gae.googleusercontent.com) or google.com (google-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
- 496
- IPv4
- 248
- IPv6
- 248
First entries at fetch time: 2001:4860:4801:4004::/64, 2001:4860:4801:4008::/64, 2001:4860:4801:4009::/64
SHA-256 of the fetched body: 5590a1a5d2fbe83872191aa2d8d45e9c854c56c49b742df9d33b7612f5482a5a
Common questions
Does Google Read Aloud obey robots.txt?
Generally no. Google classes it as a user-triggered fetcher, and its documentation says such fetchers generally ignore robots.txt because a person requested the page. No robots.txt token is documented for Read Aloud, so a Disallow rule has no documented effect; server-level blocking is the documented option.
How do I verify Google Read Aloud?
Run a reverse DNS lookup on the source IP; the hostname should end in gae.googleusercontent.com or google.com, and a forward lookup of that hostname must return the same IP. As an alternative, match the IP against Google's user-triggered-fetchers-google.json, published under developers.google.com/static/crawling/ipranges/.
Does Google Read Aloud run JavaScript?
Google's documentation says the fetcher uses stateless rendering and must access the page to see its meta tags, per the 2025-12-02 changelog. It does not state whether JavaScript is executed during that rendering, so treat script execution as undocumented.
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.