Chrome Privacy Preserving Prefetch Proxy is the Private Prefetch Proxy operated by Google. When Chrome predicts that a user is likely to navigate to a page next, it fetches that page in advance through this proxy so the page renders immediately if the user follows the link; the proxy relays the request so the destination site does not learn the user IP address. Requests therefore represent real Chrome user navigation rather than automated crawling, and carry the header Sec-Purpose: Prefetch; anonymous-client-ip. Site owners can decline prefetching per origin by serving a /.well-known/traffic-advice document with disallow set to true, or by rejecting prefetch requests with a 503 response and Cache-Control: no-store. Google publishes the proxy addresses as an RFC 8805 geofeed at https://www.gstatic.com/chrome/prefetchproxy/prefetch_proxy_geofeed. Blocking this traffic removes a page load performance benefit for real Chrome users rather than stopping a crawler.

At a glance

Operator: Google
Type: Other

How Centinel checks it

User agent: The request calls itself this crawler. Anyone can send the same string.
IP ranges: The operator publishes the addresses it crawls from, and Centinel checks the client address against that list.

A request that passes one of these checks is Chrome Privacy Preserving Prefetch Proxy itself. One that only matches the user agent is reported as unverified. The match tokens, verification domains, and address feeds are not published here.

Allowing or blocking it

The crawler object in the /validate response sets access_allowed to true only for a verified source that your tenant allowlists. A policy rule can allow or block this crawler by its category, Other.

Back to the crawler catalog