When it comes to protecting your device from malware, viruses, and other threats, a reliable firewall is essential. Fortunately, there are many free and open-source alternatives to commercial antivirus software available for Windows, Mac, and Linux. Here are five options you can consider:
1. **Windows Firewall**: The built-in option on Windows devices helps protect against malware, viruses, and other threats. It filters incoming and outgoing network traffic and blocks or allows traffic based on IP addresses, protocols, and port numbers.
2. **GlassWire**: This easy-to-use package works with Windows Firewall to block suspicious apps and connections. It sends alerts for each event through its Log Analysis feature and keeps an eye on all active apps.
3. **TinyWall**: With just 2MB in size, TinyWall is a lightweight firewall app that enhances Windows Firewall without adding unnecessary complexity. It creates a protective layer that makes managing inbound and outbound traffic easier and includes a learning mode to minimize excessive alerts.
4. **PeerBlock**: An open-source firewall tool designed to block connections from specific IP addresses and domains, PeerBlock runs quietly in the background and enforces user-defined rules without requiring constant oversight.
5. **Portmaster**: A modern firewall that emphasizes user control and transparency, Portmaster provides detailed logs of all connection attempts and allows for granular control over network access.
Source: https://www.xda-developers.com/best-free-firewall-software-windows