LuLu
LuLu is the free open-source macOS firewall
LuLu is a free, open-source firewall for Mac that lets you monitor and block which apps on your computer can connect to the internet or other networks.
LuLu is a free, open-source firewall for Mac computers. A firewall watches the connections your computer tries to make to the internet or other networks, and LuLu is built specifically for macOS.
The repository's README is brief: it names the product, links to the full documentation on the developer's website (objective-see.com), and includes a link to a Patreon page for those who want to support its development financially. The source code itself is here, but the detailed usage instructions live on the external documentation page.
Objective-See is a well-known name in Mac security tooling. LuLu fits that pattern: it is a security-focused utility for people who want to monitor and control outbound network connections from their Mac. Beyond that description, the README does not provide additional technical or functional detail.
Where it fits
- Block a specific app from making unauthorized outbound internet connections on your Mac.
- Monitor which processes on your Mac are sending data to external servers.
- Audit outbound network traffic to detect unexpected or suspicious app behavior.