Little Snitch
Host-based application firewall
From Wikipedia, the free encyclopedia
Little Snitch and Little Snitch for Linux are a multi-platform pair of host-based application firewalls supported by Objective Development Software GmbH for macOS and Linux-based desktop computer systems, respectively. Each can be used to monitor applications, preventing or permitting them to connect to attached networks through advanced rules.
| Little Snitch | |
|---|---|
The logo for Little Snitch 4 | |
| Developer | Objective Development Software GmbH |
| Stable release | 6.3.3 (November 19, 2025[1]) [±] |
| Written in | Objective-C |
| Operating system | macOS, Linux |
| Available in | German, English |
| Type | Firewall |
| License | Proprietary (macOS); mixed GPLv2 and proprietary components (for Linux) |
| Website | obdev |
| Repository | github |
Unlike a stateful firewall, which is designed primarily to protect a system from external attacks by restricting inbound traffic, Little Snitch is designed to protect privacy by limiting outbound traffic.[2] Until Little Snitch 4, it controlled network traffic by registering kernel extensions through the standard application programming interface (API) provided by Apple, but at version 5 it switched to using Apple's Network Extensions due to the deprecation[3] of kernel extensions on macOS Catalina.[4]
When an application or process attempts to establish a network connection, Little Snitch presents a dialog that allows the user to deny or permit the connection once, for a limited time, or permanently. The dialog also allows the user to restrict the parameters of the connection, for example allowing a given application to only connect to a certain domain or using a specific protocol or port. Little Snitch's integral network monitor shows ongoing traffic in real time with domain names and traffic direction.
The application (version 4) received a positive 4.5/5 review from Macworld.[5]
In 2026 a Linux version was released. While the macOS version is written in Objective-C, the Linux version is written in Rust.
