What Chrome Prefetch Proxy does
Chrome Prefetch Proxy traffic comes from Chrome prefetching links, notably from Google Search results, through a CONNECT proxy that hides the user's IP address from the destination site so pages load faster when the user clicks. The documentation is aimed at network administrators who filter content by DNS. Chrome checks a DNS signal at dns-tunnel-check.googlezip.net, and if the network indicates it needs visibility, Chrome enters a preflight mode where it issues a DNS lookup for the target domain before using prefetched resources, showing an error page if the lookup is refused or returns NXDOMAIN.
How to identify Chrome Prefetch Proxy
Temso identifies Chrome Prefetch Proxytraffic by matching the request's User-Agent header against this pattern. User-agent strings can be spoofed, so treat a match as an indication, not proof.
Chrome Privacy Preserving Prefetch ProxyChrome Prefetch Proxy FAQ
What is Chrome Prefetch Proxy?
It is the proxy Chrome uses to prefetch links, notably from Google Search results, so pages load faster when clicked. The CONNECT proxy hides the user's IP address from the destination site during the prefetch.
Can I block Chrome Prefetch Proxy with robots.txt?
The documentation does not describe any robots.txt behavior for this traffic; it is a proxy prefetching pages ahead of likely user navigations, not a search crawler. The control the documentation describes is aimed at network administrators, who can use a DNS-based signal via dns-tunnel-check.googlezip.net to make Chrome perform a visible DNS lookup before using prefetched content.
About Operational Bots
Monitoring, security scanning, link previews, webhooks, and feed fetchers: the utility traffic that keeps integrations and shared links working.
Most of this traffic is service-critical or user-triggered. Webhooks and previews don't follow robots.txt, and blocking them tends to break things you rely on.
