They don&#x27;t cover the same use cases.<p>Little Snitch is basically a user-friendly general-purpose application Firewall. When a connection hasn&#x27;t been whitelisted before, it pop up a dialog box allowing you to accept&#x2F;reject connection to a host&#x2F;domain&#x2F;port permanently&#x2F;temporarily.<p>uMatrix does not protect you against &#x27;malicious&#x27; connections initiated by non-browser applications. Little Snitch does not provide the fine-grained URI-level filtering that uBlock&#x2F;uMatrix provide.<p>Edit: if you have a Mac, Little Snitch is well-worth the money. It is very polished, does the job, and the developers are not greedy (I think I purchased an update once after I started using it in 2007 or 2008).