Supports "Connection: keep-alive". Outgoing connections can
be kept alive independently from the client.
Supports IPv6, provided the operating system does so too,
and the configure script detects it.
Supports tagging which allows to change the behaviour
based on client and server headers.
Supports https inspection which allows to filter https requests.
Can be run as an "intercepting" proxy, which obviates the need to
configure browsers individually.
Sophisticated actions and filters for manipulating both server and client
headers.
Can be chained with other proxies.
Integrated browser-based configuration and control utility at http://config.privoxy.org/
(shortcut: http://p.p/). Browser-based
tracing of rule and filter effects. Remote toggling.
Web page filtering (text replacements, removes banners based on size,
invisible web-bugs
and HTML annoyances, etc.)
Modularized configuration that allows for standard settings and
user settings to reside in separate files, so that installing updated
actions files won't overwrite individual user settings.
Support for Perl Compatible Regular Expressions in the configuration files, and
a more sophisticated and flexible configuration syntax.
GIF de-animation.
Bypass many click-tracking scripts (avoids script redirection).
User-customizable HTML templates for most proxy-generated pages (e.g. "blocked" page).
Auto-detection and re-reading of config file changes.
Most features are controllable on a per-site or per-location basis.
Many smaller new features added, limitations and bugs removed.