If you use MacOS and you would like the functionality of Little Snitch but don’t want to pay for it, this might be an alternative to consider. I haven’t tested it, nor have I done a feature comparison between LuLu and Little Snitch, so this is just to note that it exists and nothing more.

In today’s connected world, it is rare to find an application or piece of malware that doesn’t communicate with a remote server.

LuLu is the free, open-source firewall that aims to block unknown outgoing connections, protecting your privacy and your Mac!

Source: Objective-See: LuLu