Little Snitch offers a free, built-in demo mode that provides the same protection and functionality as the full version. The demo runs for three hours, and it can be restarted as often as you like. The Network Monitor expires after 30 days.
OS X 10.6 Snow Leopard or newer required.
Nightly builds are pre-release versions of Little Snitch that include the latest bug fixes and feature enhancements.
OS X 10.8 Mountain Lion or newer required. This version can be installed on OS X 10.10 Yosemite.
Are you using OS X 10.6 or earlier?
Compatible builds are available on our legacy page.