LuLu vs Radio Silence (2026): which should you pick?

Pick LuLu if

• Fits if you want to see which Mac apps connect to the internet
• Works for people who want a free firewall for outgoing traffic

Look elsewhere if

• Skip it if you want protection for incoming traffic, as it watches outgoing connections only
• Watch out: the maker says some traffic can't be blocked because it bypasses Network Extensions
• Tight if you dislike setup, as install needs several manual approvals in System Settings
• Watch out: macOS 15.3 or later is recommended because of network problems in early macOS 15

Pick Radio Silence if

• Fits if you want to stop specific Mac apps from phoning home
• Works for people who want a one-time purchase instead of a subscription

Look elsewhere if

• Skip it if you use Windows or Linux, as only macOS is covered
• Tight if you want to evaluate it properly: the trial lasts 24 hours
• Too light for you if you want rules by port or address, as only per-app blocking is described
• Watch out: it isn't sold on the Mac App Store, since the vendor says firewalls can't be

LuLu

• The maker says some traffic does not pass through Network Extensions, so LuLu cannot block it.
• It recommends macOS 15.3 or later because of networking problems in early macOS 15 releases.
• Installation needs several manual approvals in System Settings.

Radio Silence

• macOS only: version 3.4 needs macOS 10.15 or newer, and older systems use legacy versions.
• Not sold through the Mac App Store; the vendor says firewalls cannot be, because of the system access they need.
• The trial lasts 24 hours, though the vendor adds a 30-day money-back guarantee on purchases.
• Blocking is per app; the vendor's pages describe no rules by port or address.

LuLu

Outbound blocking

Alerts on and blocks outgoing connections from apps that have no rule yet.

Rules

Create allow or block rules, with options to auto-allow Apple programs and installed apps.

Passive mode

Runs without alerts, applying existing rules and allowing or denying new connections automatically.

Block mode

Blocks all traffic routed through LuLu, except destinations on an allow list.

Lists

Allow and block lists in the settings window, alongside rule and update options.

Network Extension

Uses Apple's Network Extension framework, which needs manual approval in System Settings.

Radio Silence

Outbound app blocking

Build a list of apps that may not reach the internet. The FAQ says the built-in macOS firewall does not stop outbound traffic, while this one does.

Live network monitor

Shows every network connection made by apps and processes as it happens, so a misbehaving app can be found and blocked from the list.

Helpers and background processes

Finds helper apps, invisible background processes, daemons and XPC services that make connections, and blocks child processes of a blocked app.

Runs without the window open

The firewall starts with the Mac and stays active after the window is closed; the interface is only used to change the block list.

Local traffic still allowed

A blocked app cannot reach the network but can still talk to local processes on the same Mac.

LuLu

• LuLu$0

  Free and open source; the source is linked from the product page.

Radio Silence

• Personal$9

  one-time, for a single user

  One license for one person; the FAQ says it can be installed on all of that person's Macs.

• Team$49

  one-time, for a whole team

  Covers an entire team with no seat limit. Not a subscription.