# ERR\_PROXY\_CONNECTION\_FAILED errors with HTTP proxies

DevFeed: [ERR\_PROXY\_CONNECTION\_FAILED errors with HTTP proxies](<https://devfeed.tech/articles/err-proxy-connection-failed-errors-with-http-proxies-19092.md>)

Original publisher: [Read original article](<https://httptoolkit.com/blog/proxy_connection_failed/>)

Author: HTTP Toolkit; Tim Perry

Published: 2024-12-11T17:00:00Z

Content type: tutorial

Language: en

Sources: [HTTP Toolkit](<https://devfeed.tech/sources/http-toolkit.md>)

Topics: [HTTP](<https://devfeed.tech/topics/http.md>), [browser](<https://devfeed.tech/topics/browser.md>), [Security](<https://devfeed.tech/topics/security.md>), [debug](<https://devfeed.tech/topics/debug.md>), [TLS (Transport Layer Security)](<https://devfeed.tech/topics/tls.md>), [cURL](<https://devfeed.tech/topics/curl.md>), [Postman](<https://devfeed.tech/topics/postman.md>)

Tags: [authentication](<https://devfeed.tech/tags/authentication.md>), [browser](<https://devfeed.tech/tags/browser.md>), [chrome](<https://devfeed.tech/tags/chrome.md>), [curl](<https://devfeed.tech/tags/curl.md>), [debugging](<https://devfeed.tech/tags/debugging.md>), [errors](<https://devfeed.tech/tags/errors.md>), [http](<https://devfeed.tech/tags/http.md>), [issue](<https://devfeed.tech/tags/issue.md>), [port](<https://devfeed.tech/tags/port.md>), [postman](<https://devfeed.tech/tags/postman.md>), [protection](<https://devfeed.tech/tags/protection.md>), [proxy](<https://devfeed.tech/tags/proxy.md>), [server](<https://devfeed.tech/tags/server.md>), [tcp](<https://devfeed.tech/tags/tcp.md>), [tls](<https://devfeed.tech/tags/tls.md>), [tools](<https://devfeed.tech/tags/tools.md>)

## AI overview

This tutorial explains how to diagnose ERR_PROXY_CONNECTION_FAILED when using a local debugging proxy with Chrome or similar applications. It covers incorrect connection details, unreachable proxies, and antivirus software that intercepts local proxy traffic and rejects the proxy's TLS certificate.

## Source excerpt

If you're using a local debugging proxy tool like HTTP Toolkit, you might run into the dreaded ERR_PROXY_CONNECTION_FAILED error in Chrome and other similar apps. This can be a very frustrating and unhelpful error! There's only a few possible causes though, and it's usually easy to fix. The Simple Case The simplest explanation is exactly what it says: the browser can't connect to your proxy. In the simple case this may be caused by a basic connection issue: you have the address, port or some authentication details wrong, or the details are correct but the proxy is just not reachable on your connection, and so the browser can't talk to it. The easiest way to confirm this is to try connecting to the details directly using an HTTP client tool like curl, Postman, or the HTTP Toolkit Send page, to manually check if the server is listening on the port you expect. If you see a TCP error then the details are wrong, but if you see any kind of HTTP error or similar then you know that the server does exist and it's reachable with the given details. If the failure comes from a browser intercepted by a tool like HTTP Toolkit though, where intercepted clients are preconfigured & launched for you, this is not what's happening - the server is definitely reachable (it's running locally) and the config is correct (it's been done automatically). Instead, this might be caused by something more complicated... Beyond the Simple Case If you know the settings are correct, and you know the proxy is reachable, what could cause this ERR_PROXY_CONNECTION_FAILED error? Once you're ruled out basic connection issues, the most likely cause is antivirus software on your computer that is intercepting your connections. This is becoming a common feature of some antivirus & security software, most notably ESET. It's not directly related to viruses at all, but is a separate security feature that's often enabled automatically for additional protection. What happens in this case is that your browser is tryi