Many OS X system daemons, autonomous bits of low-level software, also get pre-approved. For example, Safari requests data from port 80 (non-secure Web connections) and port 443 (https connections) to pass through without notice. Little Snitch comes configured to allow common activities. (An IP address is a destination, like an apartment building a port is like a specific apartment within the building.) For instance, you can approve connections to all ports on a domain, or click on the allow/deny dialog to specify a port. Click a button here and there-like a downward-pointing arrow to the left of the Deny button-and you can expand options and limit choices. The default view offers simple details that shouldn’t frighten someone with no real technical knowledge as long as they get what a domain name represents and what apps are trying to do. The utility lets you drill down nearly everywhere. Clicking Allow or Deny adds a rule to Little Snitch’s configuration, bypassing this dialog in the future for varying degrees of specificity and periods of time. Using the previous example with a browser that’s not pre-approved, you might see an alert that Google Chrome is trying to connect to. This expanded network-connection popup shows information about the app and all the duration options for allowing or denying.įor previously unknown connections, Little Snitch presents a dialog box that shows you the requesting app’s icon, its name, and what it’s attempting to do. Enabling it likely causes more problems and confusion for less-experienced users than leaving it off, but a Mac with unfettered bidirectional access isn’t a good thing, either. The firewall option in the Security & Privacy system preference pane is extremely coarse and lacks necessary features. It’s bizarre that this many decades into the net’s evolution, Apple still doesn’t include strong tools enabled by default that restrict access to your Mac or examine connections from macOS or apps you’re running out to the Internet. But the app has significant updates for visualizing connections and improves how it explains what apps are trying to do. Version 4 refines and extends this friendly firewall, and if you’ve used it or looked at it in the past, you’ll find it mostly familiar. The Internet is a terrifying place, and Objective Development’s Little Snitch 4 ($45) has tried for many years to help keep your Mac locked down by monitoring connections and letting you control inbound and outbound traffic.