Best Privacy-Focused Firewalls
A firewall gives you control over which applications and services can send or receive data from your device. Using an open‑source, privacy‑focused firewall helps you block unwanted connections, prevent trackers, and stop data leaks – without relying on proprietary solutions that may spy on you. Here are the top choices for Windows, macOS, Linux, and Android.
Portmaster
Powerful (& beautiful) firewall program for Windows & Linux to give you finer control over what your device connects to.
Lulu
Firewall program for macOS to give you finer control over what your device connects to.
rethinkDNS
Block malware, spyware, ads, and trackers across all apps with Rethink DNS. Servers in 300+ locations: Experience blazing fast speeds.
NetGuard
Firewall program for Android (no root required) to give you finer control over what your device connects to. Warning: NetGuard by default takes the place of a VPN on Android.