Pick LuLu if you want a free, open-source outbound firewall that asks before new apps connect. Pick Little Snitch if you want the most capable Mac firewall: profiles, detailed rules, blocklists, built-in encrypted DNS and a first-class network monitor with a map. Both block connections that macOS's built-in firewall (incoming only) can't.
Criterion by criterion
| Criterion | LuLu | Little Snitch |
|---|---|---|
| Price | Free | €59 single license; demo runs in 3-hour sessions |
| Open source | Yes | No |
| Blocks outgoing connections | Yes, with alerts | Yes, with alerts or silent modes |
| Rules | Per app or endpoint, with expiry | Detailed rules, groups and profiles |
| Blocklists | Local or remote host and IP lists | Curated topic lists, updated daily |
| Network monitor | Separate tool (Netiquette) | Built in, with a map |
| Encrypted DNS | No | Built in (DoH, DoT, DoQ) |
| macOS support | macOS 10.15 or later | Current macOS versions |
| LuLu | Little Snitch | |
|---|---|---|
| Price | Free | €59 single license (free demo mode) |
| Platforms | macOS | macOS |
| Blocks connections | Yes | Yes |
| Per-app bytes / live rate | Not listed | Yes |
| Map view | Not listed | Yes |
| Open ports view | Not listed | Not listed |
| DNS / domain names | Not listed | Yes |
| Open source | Yes | No |
| macOS support | macOS 10.15 or later | Not listed |
| Last checked | 24 Oct 2026 | 24 Oct 2026 |
Which to pick
Pick LuLu if…
- You want a free, trustworthy firewall with source code you can read.
- You only need to approve or block new connections.
- You prefer a small tool with few settings.
Pick Little Snitch if…
- You want profiles (home, work, travel) and fine-grained rules.
- You want blocklists and encrypted DNS in the same app.
- You want a built-in network monitor and map of where connections go.
Frequently asked questions
Is LuLu as good as Little Snitch?
For basic outbound blocking, yes. Little Snitch adds profiles, richer rules, blocklists, encrypted DNS and a far more detailed monitor.
Can I run LuLu and Little Snitch together?
It isn't recommended: two network-filter extensions both prompting and filtering cause confusion and conflicts. Choose one.
Is LuLu safe?
LuLu is open source and made by Objective-See, founded by security researcher Patrick Wardle, and is widely used and trusted.
Do I need either if macOS has a firewall?
macOS's firewall only controls incoming connections. To control what your apps send out, you need an outbound firewall like these.