You must purchase the license directly from the official Radio Silence website.
Note: If your trial has already expired, the app will automatically prompt you for the license key upon opening. Troubleshooting License Issues
| Feature | Radio Silence ($9) | Little Snitch (≈$59) | LuLu (Free) | | :--- | :--- | :--- | :--- | | | One-time payment ($9) | One-time payment (≈$45-$59) | Free (Donationware) | | Ease of Use | Very simple "Allow/Block" toggle | Complex; requires user knowledge of network rules | Moderate; requires administrative privileges | | User Interface | Minimalist and invisible | Highly detailed; custom rule creation | Standard; functional but less polished | | Pop-ups | None; always runs silently | Frequent pop-ups asking for permissions | Frequent alerts for new connections | | Best For | Users who want to block specific, known troublemakers | Power users/Developers who need granular control | Tech-savvy users who want free, open-source security |
To register before the trial ends, go to the application menu and select "Register…" No Re-install Needed:
Radio Silence is not available on the Mac App Store because Apple doesn't allow applications that require the level of deep system networking access that firewalls do. Therefore, you must buy the license directly from the developer. The full version costs a one-time fee of only $9 .
A standout feature of Radio Silence is its user-friendly license agreement.
This is the most common comparison in the Mac firewall space. Both are excellent but serve different needs.
Radio Silence is built and maintained by independent developers who rely on software sales to fund continuous development. Purchasing an official license key is cheap compared to major security suites and offers several distinct advantages: