Mac firewall and permission guides

How to block an app from the internet, choose an outbound firewall and control which files an app can access on Mac, with the limits of the built-in tools explained.

• How to block an app from accessing the internet on MacThe macOS firewall only filters inbound traffic and cannot stop an app phoning home. Why you need an outbound firewall, and how to block a specific app in 3 steps.
• Choosing a Mac firewall: Little Snitch vs LuLu vs AppPermitThree outbound firewalls for macOS — Little Snitch, LuLu and AppPermit — compared on network control, file access, program activity, AI help, price and trial.
• How to control which files an app can access on MacmacOS “Files and Folders” permissions cover only a few system folders. How to set per-app file access on Mac — read and write, read-only, ask — plus folder rules.