Little Snitch is a tool designed to alert you on outgoing network connections. Little Snitch runs in the background and hooks into the operating system kernel while you are logged in. When an application tries to establish a network connection, Little Snitch intercepts the attempt and brings up an alert panel, telling you all the connection details including the name of the application which initiated the connection. You either choose to allow or deny the connection in the specific case, or to add a permanent rule for future connections initiated by the same application. Little Snitch runs inconspicuously in the background and it can also detect network related activity of viruses, trojans and other malware.

Protect your privacy:
• Little Snitch informs you whenever a program attempts to establish an outgoing Internet connection. You can then choose to allow or deny this connection, or define a rule how to handle similar, future connection attempts. This reliably prevents private data from being sent out without your knowledge.

Define whom you trust:
• Little Snitch provides flexible configuration options, allowing you to grant specific permissions to your trusted applications or to prevent others from establishing particular Internet connections at all. So you will only be warned in those cases that really need your attention.

Keep an eye on your traffic:
• Little Snitch includes a Network Monitor, showing detailed information of all incoming and outgoing network traffic. A status icon in the menu bar provides a summary of current network activity, and a monitor window with more comprehensive information pops up automatically in case of new traffic events.

• Rule based traffic filtering
• Connection alert warns about Internet access for which no rule exists yet
• Network Monitor for visualizing and analyzing network activity in real-time
• Powerful configuration interface
• “via” rules for applications communicating via Unix tools
• DNS based rules
• Domain wildcard rules
• Comprehensive multi user support
• Rules can be defined per-user or globally for all users
• IPv6 support

Limitations: 3-hour trial.

Requirements:
OS X 10.15+