Privoxy vs Squid

Privoxy is free, non-caching web proxy software for privacy controls, access rules, and changes to HTTP headers and web pages. It can modify page text, remove banners and web bugs, filter HTML annoyances, and inspect HTTPS requests and responses. A browser-based configuration and control utility includes rule tracing and remote toggling, and Privoxy can be chained with other proxies. It can serve multiple clients across a network or as a LAN gateway. The software runs on Windows, GNU/Linux, Mac OS X, Haiku, BSD variants, Solaris, and other Unix systems. It is licensed under the GNU GPL version 2 or later, with a free plan listed at free. A basic configuration is included with a new installation, but many advanced features need to be enabled. Privoxy handles HTTP and HTTPS proxying; it does not handle FTP, SMTP, instant messaging, IRC, or ICQ. It is not designed as a malware-removal tool, and the default setup does not filter malware. The project says it lacks trusted build infrastructure; individual project members or external contributors build and upload binary packages.

Squid is a self-hosted caching proxy for web traffic. It keeps commonly requested pages and other supported data available for reuse, helping reduce bandwidth and improve response times. Squid handles HTTP, HTTPS, FTP, and gopher data; supported cache engines also include ICP and HTCP. Administrators can apply access controls and use full request logging. Squid can accelerate servers, direct content among web servers, and organize content clusters for load balancing. Multiple caches can be connected as a mesh or hierarchy through parent and sibling links. Proxy authentication options include Basic, NTLM, Digest, and Negotiate, with bundled helpers for LDAP, SQL databases, PAM, RADIUS, and Windows domains. Basic authentication encodes credentials with Base64 rather than encrypting them, so credentials are effectively cleartext between browser and proxy. Squid is free to download, use, and modify, and is distributed under GPL version 2, with some components under compatible open-source licenses. It is available for Linux, macOS, and Windows, with installation through operating-system packages, source releases, and binaries. Documentation, a wiki, bug tracking, and mailing lists are available.