portmaster

# Get Peace of Mind <br> with [Easy Privacy](https://safing.io/)

Portmaster is a free and open-source application firewall that does the heavy lifting for you.
Restore privacy and take back control over all your computer's network activity.

With great defaults your privacy improves without any effort. And if you want to configure and control everything down to the last detail - Portmaster has you covered too. Developed in the EU 🇪🇺, Austria.

__[Download for Free](https://safing.io/download/)__

__[About Us](https://safing.io/about/)__

![Portmaster User Interface](https://safing.io/assets/img/page-specific/landing/portmaster-thumbnail.png?)

_seen on:_  

[<img src="https://safing.io/assets/img/external/heise_online.svg" height="35">](https://www.heise.de/tests/Datenschutz-Firewall-Portmaster-im-Test-9611687.html)
&nbsp;&nbsp;&nbsp;
[![ghacks.net](https://safing.io/assets/img/external/ghacks.png)](https://www.ghacks.net/2022/11/08/portmaster-1-0-released-open-source-application-firewall/)
&nbsp;&nbsp;&nbsp;
[![Techlore](https://safing.io/assets/img/external/techlore.png)](https://www.youtube.com/watch?v=E8cTRhGtmcM)
&nbsp;&nbsp;&nbsp;
[![Lifehacker](https://safing.io/assets/img/external/logos/lifehacker.webp)](https://lifehacker.com/the-lesser-known-apps-everyone-should-install-on-a-new-1850223434)

## [Features](https://safing.io/features/)

1. Monitor All Network Activity
2. Full Control: Block Anything
3. Automatically Block Trackers & Malware
4. Set Global & Per‑App Settings
5. Secure DNS (Doh/DoT)
6. Record and Search Network Activity ([$](https://safing.io/pricing/))
7. Per-App Bandwidth Usage ([$](https://safing.io/pricing/))
8. [SPN, our Next-Gen Privacy Network](https://safing.io/spn/) ([$$](https://safing.io/pricing/))

# Technical Introduction

Portmaster is a privacy suite for your Windows and Linux desktop.

### Base Technology

- Portmaster integrates into network stack using nfqueue on Linux and a kernel driver (WFP) on Windows.
- Packets are intercepted at the raw packet level - every packet is seen and can be stopped.
- Ownership of connections is found using eBPF and `/proc` on Linux and a kernel driver and the IP Helper API (`iphlpapi.dll`) on Windows.
- Most settings can be defined per app, which can be matched in different ways.
- Support for special processes with weird or concealed paths/actors:
  - Snap, AppImage and Script support on Linux
  - Windows Store apps and svchost.exe system services support on Windows
- Everything is 100% local on your device. (except the SPN, naturally)
  - Updates are fully signed and downloaded automatically.
  - Intelligence data (block lists, geoip) is downloaded and applied automatically.
- The Portmaster Core Service runs as a system service, the UI elements (App, Notifier) run in user context.
- The main UI still uses electron as a wrapper :/ - but this will change in the future. You can also open the UI in the browser

### Feature: Secure DNS

- Portmaster intercepts "astray" DNS qu