Why Chrome’s ERR_NAME_NOT_RESOLVED Can Disappear Through Fiddler
Interpret a Chrome DNS failure that disappears when an ordinary HTTP proxy handles the destination connection.
A website can fail with ERR_NAME_NOT_RESOLVED on Chrome’s direct route and work through local Fiddler because the two paths assign the hostname lookup to different components.
With an ordinary HTTP proxy, Chrome sends the destination hostname to that proxy for forwarding or CONNECT. Chrome still needs to reach the proxy endpoint, but the proxy handles the outward destination connection. A local Fiddler instance can resolve that name itself or send it to a configured parent.
The successful request therefore narrows the investigation. Compare Chrome’s direct resolver path with the proxy’s actual path, including its parent selection and any destination override. It does not establish that every Windows DNS lookup was broken.
Retain the precise hostname and effective proxy decision when comparing results. Resetting network stacks, disabling IPv6 or changing unrelated DNS registration settings before identifying that difference can remove useful evidence without explaining it.