Radio Silence is a paid macOS firewall utility that lets you block any app from accessing the internet — silently, permanently, and without battery drain.
What is Radio Silence?
Radio Silence is a lightweight macOS application built by indie developer Juuso Salonen that gives you surgical control over which apps on your Mac are allowed to make network connections. Unlike full-blown security suites or enterprise firewalls, it does exactly one thing: block outbound traffic per-app, on demand, with zero overhead. You add an app to the block list, and that app goes dark. No popups, no logs to wade through, no persistent background daemon eating your RAM.
I stumbled onto Radio Silence while hunting down a trial-ware app that kept phoning home to verify its license after I'd already paid for it. Five minutes after installing Radio Silence, the problem was solved — and I've kept it on every Mac I've owned since.
What does Radio Silence do best?
Radio Silence excels at silent, friction-free blocking with essentially zero performance footprint. Where Little Snitch — its most obvious competitor — presents you with a permission dialog every time an app first hits the network, Radio Silence trusts you to add blocklist entries yourself, then stays completely out of the way. There's no menubar icon blinking at you, no notification center pings, no interruption to your flow.
- Per-app blocking — drag any app into the block list; Radio Silence uses the macOS packet-filter firewall under the hood, so blocking is enforced at the kernel level, not in user space.
- Process-level matching — child processes spawned by a blocked parent are also caught, closing the loophole where an app forks to a helper to bypass app-level rules.
- No daemon, no polling — rules are baked into the system firewall; Radio Silence itself doesn't need to run continuously to enforce them.
- Minimal UI — a single window, a search bar, a list. Everything you need; nothing you don't.
That philosophy makes it especially appealing to developers who want to stop a local service from calling out during testing, or to privacy-conscious users who want to quarantine an app that has no legitimate reason to reach the internet.
How much does Radio Silence cost?
Radio Silence is a paid download available directly from the developer's website. There is a free trial so you can verify it works with your setup before buying; the one-time purchase price is modest compared to the subscription cost of competing security suites. It is not on the Mac App Store, which means the purchase happens through the developer's own storefront — straightforward and without Apple's 30% cut complicating the pricing.
Who should use Radio Silence?
Radio Silence is the right tool if you want a dead-simple answer to a specific question: "can I stop this particular app from reaching the internet?" It suits developers isolating apps during testing, privacy-focused users suspicious of telemetry-happy software, and anyone annoyed that a purchased app keeps validating its license against a remote server.
It is not the right tool if you want a full network monitor with per-connection logs, bandwidth graphs, or interactive allow/deny dialogs. For that workflow, Little Snitch or Lulu are the better picks. Little Snitch gives you a rich rule editor and real-time connection map; Lulu is open-source and similarly interactive. Radio Silence deliberately opts out of that complexity — and that restraint is a feature, not a gap, for the right user.
If you run a Mac used by one informed person who knows what they want to block, Radio Silence is nearly perfect. If you're managing a shared family machine where you need to audit every outbound connection, the interactive alternatives will serve you better.
What are the best Radio Silence alternatives?
The strongest alternatives sit in two camps. Little Snitch (Objective Development) is the gold standard for interactive network monitoring on macOS — verbose, powerful, and priced accordingly. Lulu by Patrick Wardle is open-source and takes a similar interactive approach to Little Snitch at no cost. If your goal is only ad and tracker blocking inside browsers, something like AdGuard for Mac covers that slice without touching system-level firewall rules. Radio Silence lives in a narrower, quieter lane than all of these — and that focused simplicity is precisely its selling point.
How does Radio Silence compare to Little Snitch?
Little Snitch notifies you and asks for a decision every time a new connection is attempted — you're an active gatekeeper. Radio Silence assumes you already know what you want to block, lets you set the rules once, and disappears. Little Snitch's connection map and bandwidth logging are genuinely impressive; Radio Silence has no equivalent. Conversely, Radio Silence installs and configures in under a minute, requires no ongoing decisions, and has no measurable impact on battery life. For the use case of "I want to permanently block these three apps," Radio Silence is faster to configure and cheaper to run than Little Snitch — which starts to feel like overkill.
