3proxy

3proxy is a free, self-hosted proxy server for controlling connections between internal and external networks. It suits technically capable users and administrators who need protocol choice and granular traffic controls. Its breadth is useful, but configuration and security require care.

Overview

3proxy brings multiple proxy protocols and network services into one small server, with access controls, traffic limits, logging and proxy chaining. That makes it a flexible option for managed network access, though less suitable for anyone looking for a turnkey hosted service.

Its network services span HTTP, HTTPS, SOCKS4, SOCKS4.5, SOCKS5, FTP, POP3, SMTP, IMAP, DNS, TCP and UDP. The supported-protocol list covers HTTP, HTTPS, SOCKS4, SOCKS4.5, SOCKS5, FTP, TCP and UDP.

For broader comparisons, see Forward Proxy Software and Proxy Software.

Key features

HTTP and HTTPS proxying, three SOCKS versions and FTP over HTTP cover common relay needs. POP3 proxying, TCP and UDP port mapping, and a caching DNS proxy extend its role beyond web traffic. This range is valuable for administrators consolidating network services, but requires choosing and configuring the right combination.

Access controls can be paired with bandwidth and traffic-amount limits; proxy chaining and log rotation are also supported. Logs can go to files, Unix syslog or an ODBC database, with a configurable format. These options give administrators control over both traffic and records, while optional ODBC support means database logging depends on the build.

When built with OpenSSL, 3proxy can provide HTTPS proxy connections, TLS connections to upstream servers with certificate authentication, and mutual TLS. Those capabilities are conditional rather than inherent in every build. Documentation also lists optional support for PCRE2 and PAM.

Security guidance recommends restricting access with ACLs and warns that the documented strong authentication method currently uses cleartext authentication. That caveat makes careful network restriction essential; readers who cannot manage ACLs and authentication configuration should choose another approach. Release binaries are published with SHA256 checksums, an OpenPGP signature and GitHub build provenance attestation; Docker images are signed and attested.

Pricing

3proxy costs nothing as freeware and open-source software. There is no paid tier or free trial to weigh, and no stated seat or traffic quota. Commercial support or licensing questions are directed to an email contact.

Platforms

3proxy supports Linux, macOS and Windows, and is self-hosted. Docker images provide one deployment option; Windows installation as a system service is also documented. This suits users who can manage their own server deployment, not those seeking a vendor-hosted proxy.

Who it's for

3proxy is a strong fit for technically capable users who want a no-cost, self-hosted proxy with several protocols, network services and configurable traffic controls. It is less appropriate for users who need managed hosting or a configuration that avoids security decisions around ACLs and authentication.

Pros and cons

• Pro: Broad protocol and service coverage, from HTTP and SOCKS to port mapping and caching DNS, can handle varied relay needs in one server.
• Pro: Bandwidth and traffic limits, ACLs, chaining and configurable logging give administrators meaningful control over access and operations.
• Pro: Free, open-source availability and Docker deployment offer flexibility without a software charge.
• Con: TLS features depend on compiling with OpenSSL, so they are not assured in every build.
• Con: Security guidance warns that the documented strong authentication method uses cleartext authentication, making ACL configuration and deployment choices important.
• Con: Its self-hosted configuration and broad service set are a poor match for users who want a managed, ready-to-use proxy.

Alternatives

Squid is another free, self-hosted option for Linux, macOS and Windows, with third-party commercial support potentially available.

mitmproxy is a free, open-source interactive HTTPS proxy; choose it if that focus better matches your needs.

Tinyproxy is a free, self-hosted option for Linux, macOS and supported source code under GNU GPL version 2 or above.

WinGate offers a freemium Windows option, including a Standard license for 6 concurrent users at $109.95 a month; its licensing is based on concurrently connected users.

SafeSquid Secure Web Gateway is a paid, self-hosted option for Linux and Windows with annual subscription billing; the subscription stops working if it is not renewed.

Cloudflare Gateway offers a free plan for 50 users with up to 24 hours of standard log retention, or a pay-as-you-go plan at $7 a month.

Prisma Access is a paid alternative with custom pricing.

Check Point Harmony SASE offers a 30-day trial before a software license is required.

Verdict

Choose 3proxy if you can manage a self-hosted server and want broad protocol coverage and traffic controls without a software fee. Its flexibility is the main reason to choose it; the cleartext-authentication caveat and need for careful ACL configuration are the strongest reasons to look elsewhere.