Send Chrome localhost Requests Through a Manual Proxy
Understand Chrome’s implicit loopback bypass before forcing a controlled localhost request through a manual proxy.
A public site appears in the proxy log. Your localhost test does not. Chrome has implicit bypass rules for loopback and related local destinations; an empty manually entered list does not necessarily remove them.
For a controlled manual-proxy setup, Chromium documents the subtractive rule:
--proxy-bypass-list="<-loopback>"
The minus sign matters. This removes an implicit exception; it is not another hostname to send direct. It also does not select a proxy by itself. Keep the intended manual proxy configuration and the browser instance receiving those options explicit.
Before using it, identify whose local service you mean. If a remote proxy receives a request for 127.0.0.1, the destination connection reaches the proxy's own loopback environment. A browser setting cannot make that address mean your laptop at the other end of the network.
A locally running inspection proxy is a different arrangement: it may legitimately need to receive a request for another local listener. Keep the proxy port and the web application's port distinct.
This exception affects a local protection boundary, so use it deliberately for the required session. Do not treat the setting as a general privacy improvement or copy it into an unrelated managed browser policy without reviewing the consequences.