3proxy vs mitmproxy

3proxy is a free proxy server for controlling access between internal users and external resources, or between external users and internal resources. It supports HTTP and HTTPS proxying, SOCKS v4, v4.5 and v5, and FTP over HTTP. Other services include POP3 proxying, TCP and UDP port mapping, and a caching DNS proxy. Access controls can set bandwidth and traffic limits, chain proxies, and rotate logs. Logging can use files, Unix syslog, or an ODBC database, with configurable formats. When compiled with OpenSSL, 3proxy offers HTTPS proxy connections, upstream TLS with certificate authentication, and mutual TLS. Its security guidance recommends limiting access with ACLs and notes that its documented strong authentication method currently uses cleartext authentication. It runs on Linux, macOS, Windows, and self-hosted setups; Docker images are available, and Windows system-service installation is described. Release binaries are published with checksums, an OpenPGP signature, and a build provenance attestation; Docker images are signed and attested. The listed plan is free.

mitmproxy is a free set of tools for inspecting and changing traffic sent through a proxy. It handles HTTP/1, HTTP/2, WebSocket, and SSL/TLS traffic, and can intercept HTTP and HTTPS requests and responses for editing. Conversations can be saved for later analysis, and users can replay client requests or recorded server responses. The project provides an interactive console, a browser-based GUI, and non-interactive terminal output through mitmproxy, mitmweb, and mitmdump. Proxy modes include regular, local capture, WireGuard, reverse, transparent, TUN, upstream, SOCKS5, and DNS. Python addons can alter behavior in response to events and expose commands. WireGuard mode can capture traffic from external devices or individual Android apps. A built-in certificate authority generates interception certificates as needed. Installation options cover Windows, macOS, Linux, PyPI, and official Docker images. The project says it does not phone home or check for updates. Documentation notes that HTTP/3 client replay is currently broken; dependencies in precompiled binaries and Docker images are fixed at release and cannot be updated in place.