NetMute
Why You Need a Mac Firewall in 2026
The firewall built into macOS (System Settings → Network → Firewall) controls incoming connections. It does not look at what your own apps send out, and that is where tracking happens: analytics code inside ordinary apps, telemetry from background services, calls home from menu-bar tools.
One example from the developer's own Mac: between 7 and 22 September 2026, GeForce NOW contacted 59 domains, two of them tracking endpoints (feedbacks.telemetry.data.nvidia.com and events.telemetry.data.nvidia.com). The macOS firewall does not show that, and a browser ad blocker only ever sees the browser.
An outbound firewall closes that gap: for every connection an app tries to open, it decides allow or block. What separates the tools is how that decision gets made. You answer a prompt per connection, you keep a list by hand, you switch everything off for a metered session, or a curated tracker list does most of the work and you step in only where you want to.
Below: the tools most Mac users compare, each with what it is for and what you give up.
The Top 6 Mac Firewalls Compared
The six tools people compare most, plus Little Snitch Mini, the smaller app from the same developer. Each checked against the vendor's own site on 25 September 2026.
NetMute
A per-app outbound firewall that does the tracker research for you. Tracker Shield blocks a curated list of known tracker domains without asking you about every connection, App X-Ray gives each app a privacy grade from what it actually contacts, and a check on the Overview shows, browser by browser, where blocking really works.
- Best for
- getting trackers gone without turning it into a project.
- Watch for
- a newer entrant, so less accumulated mileage than Little Snitch. In browsers that resolve names on their own, such as Brave, name-based blocking needs one extra setting; the app shows where that applies.
- Licence
- free to download, one purchase unlocks Pro, no subscription. From the Mac App Store, or directly with a licence key.
Little Snitch
Built by Objective Development in Vienna and in development for over twenty years; the current version is 6.5, released in September 2026. In alert mode it asks the first time an app opens an outbound connection and lets you allow or deny it once, until quit, or forever; a silent mode exists too. Version 6 added DNS encryption, blocklists with daily updates and a traffic chart that reaches back up to twelve months. Where an app's developer provides one, it shows an Internet Access Policy explaining what a connection is for.
- Best for
- writing the rules yourself, in depth, with the deepest editor on the platform.
- Watch for
- in alert mode, the first days bring a stream of prompts while the ruleset builds.
- Licence
- perpetual licence sold directly from obdev.at, with single, family and multi licences, reduced upgrade pricing and a student discount. The demo switches its filter off every three hours and can be restarted as often as you like.
Little Snitch Mini
A separate, smaller app from the same developer, sold only on the Mac App Store. Free as a network monitor with a live connection list, traffic diagrams and a map; blocking, longer history and advanced filters come with a subscription.
- Best for
- watching connections live and on a map.
- Watch for
- blocking is part of the subscription, and there is no one-time purchase for it.
- Licence
- free, with a monthly or yearly subscription for the full feature set.
LuLu
A free, open-source outbound firewall from Patrick Wardle and the Objective-See foundation; the current release is 4.5.1, from August 2026. It blocks unknown outgoing connections, asks you to decide and saves the answer as a rule. Block and allow lists can be loaded from a file or a URL, and a Network Monitor entry opens Objective-See's live connection viewer, Netiquette.
- Best for
- when free and auditable outweigh everything else.
- Watch for
- it ships no curated tracker list of its own and keeps no traffic history. It is deliberately minimal.
- Licence
- free, open source under GPLv3, donations welcome.
Radio Silence
Works from a block list: add the apps you want silenced and they lose network access, without pop-ups. A real-time network monitor shows every connection, and since version 3.4 lists incoming and outgoing separately.
- Best for
- a plain block list with nothing asking for your attention.
- Watch for
- blocking works app by app; which apps to silence is up to you.
- Licence
- one-time purchase, no subscription, with personal and team licences.
TripMode
A data saver for metered connections: while it is on, every app is blocked except the ones you allow. TripMode 3 adds profiles, a live monitor, a domains view and data limits, and tracks data use per app over time.
- Best for
- paying by the gigabyte, where saving data is the whole job.
- Watch for
- it is built around data use rather than privacy.
- Licence
- seven-day trial, then a monthly or yearly subscription or a one-time lifetime purchase, through the Mac App Store or Setapp.
GlassWire
Frequently searched in a Mac context, and that is the misunderstanding: GlassWire is a network monitor for Windows and Android. Checked again on 25 September 2026, there is still no macOS version.
- Best for
- Windows and Android.
- Watch for
- download pages promising a "GlassWire for Mac" build.
- Licence
- not applicable on macOS.
Also around. Vallum is an outbound firewall that runs entirely in userland, without a kernel extension. Murus is a graphical front end for the PF packet filter built into macOS. FireWally is a newer app firewall on the Mac App Store. Hands Off!, still listed in older comparisons, is no longer maintained.
Pricing Overview
How each tool is licensed and distributed, checked on 25 September 2026:
- Little Snitch
- perpetual licence sold directly from obdev.at, not via the Mac App Store. Single licence (one user on several Macs, or several users on one Mac), family licence for up to five Macs in one household for non-commercial use, multi licences, reduced upgrade pricing and a student discount. The demo can be restarted at will.
- Little Snitch Mini
- Mac App Store only. Free as a monitor; blocking and extended features by monthly or yearly subscription.
- LuLu
- free and open source under GPLv3. Donations welcome via Objective-See. No paid tier.
- Radio Silence
- one-time purchase, personal and team licences. No subscription.
- TripMode
- seven-day trial, then a monthly or yearly subscription or a one-time lifetime purchase, via the Mac App Store or Setapp.
- NetMute
- free to download from the Mac App Store or directly. A one-time purchase unlocks NetMute Pro (the full Tracker Shield, App X-Ray, network profiles, data limits, unlimited domain blocks); team licences for 5 or 10 Macs are sold directly. No subscription, no account.
- GlassWire
- not applicable (no Mac version). The bigger difference is the way of working, not the licence: answering prompts (Little Snitch, LuLu), keeping a list (Radio Silence), saving data per session (TripMode), or a curated tracker list with manual control on top (NetMute).
