# Best Mac Firewall in 2026: Choosing by What You Need

> The macOS firewall, LuLu, Radio Silence, Murus, Vallum, Little Snitch and FireAI, compared on the questions that decide the choice: direction, alerts, rules and price, from each vendor’s own pages.

FireAI Security & Research Team (HisnLabs) · Published 2026-10-04
Canonical: https://hisnlabs.com/en/blog/best-mac-firewall-2026

There is no single best firewall for a Mac, because the products below answer different questions. Some only decide who may connect to your Mac from outside; others decide where your apps may connect to; some ask you about every new connection and others stay silent. This guide compares seven options on the criteria that actually separate them. Every product fact comes from the vendor’s own website or documentation, checked on 4 October 2026, and is listed in the sources. Prices and versions change, so treat the table as a dated snapshot. One disclosure: this article is published by HisnLabs, which makes FireAI, one of the seven.

## Four questions to answer first

Direction comes first. An inbound firewall controls connections other computers open to your Mac; an outbound firewall controls connections your apps open to the internet. On a personal Mac most of the risk today travels outward: a password stealer sending what it collected, an app reporting to an analytics service, an AI agent uploading a file. The built-in macOS firewall covers only the inbound direction, which is why outbound tools exist at all. Our [guide to the built-in firewall](https://hisnlabs.com/en/blog/how-to-turn-on-mac-firewall) explains its settings in detail.

The second question is what a rule is attached to. Application firewalls write rules per app, such as “this browser may reach this website”. Packet filters write rules by address and port and do not know which app opened a connection. The third question is how you want to be involved: some tools ask you, through a pop-up, the first time an app tries something new; others block silently and let you review a list. Alerts teach you what your Mac does but take attention; silent blocking is calmer but assumes you already know what to block. The fourth question is cost and licensing: free and open source, a one-time purchase, or a subscription.

## At a glance

| Product | Direction | Rules by | New connections | Price (vendor page) | Requires |
| --- | --- | --- | --- | --- | --- |
| macOS firewall | Inbound | App | Asks when an app first accepts incoming connections | Included | Any current macOS |
| LuLu 4.5.1 | Outbound | App | Alert | Free, GPL-3.0 | macOS 10.15 or later |
| Radio Silence 3.4 | Outbound | App | No pop-ups; you add apps to a block list | $9 once | macOS 10.15 or later |
| Murus 2.7 | Inbound (Lite); outbound from Basic | Address and port (pf) | Rule-based | Lite free for non-commercial use; Basic $10; Pro $25 | macOS 10.14.4 or later |
| Vallum 5.1 | Inbound and outbound | App | Pop-up alert | $15; five-licence family pack $20 | macOS 11.2 or later |
| Little Snitch 6.5 | Inbound and outbound | App | Alert | €59 single licence | macOS 14 Sonoma to macOS 27 |
| FireAI | Outbound prompts; inbound rules enforced | App, by code signature | Prompt | €49 once; business €6 per Mac per month | See hisnlabs.com |

*Sources: each vendor’s own website, checked on 4 October 2026. Murus 3.0, in release-candidate stage, requires macOS 13.5 or later.*

## If you only need inbound protection: the macOS firewall

The firewall built into macOS is free, already installed and maintained by Apple. Apple describes it as an application firewall: you keep a list of apps and decide for each whether it may accept incoming connections, with options to block all incoming connections and a stealth mode that stops the Mac answering probing requests such as ping. On a managed Mac it can be configured centrally with a configuration profile. It does not limit outgoing connections at all, so it answers a different question from the rest of this list. Every other option here can run alongside it, and keeping it switched on costs nothing.

## If you want free outbound alerts: LuLu

LuLu, from the Objective-See Foundation, is free and open source under the GPL-3.0 licence. When an app tries to connect out for the first time, LuLu shows an alert and you allow or block it, and the decision becomes a rule. Version 4.5.1, released in August 2026, runs on macOS 10.15 or later as a universal app. Its own documentation notes a limit worth knowing: rules by hostname only work for apps that use Apple’s Network.framework or NSURLSession; other apps have to be handled by address. Our [FireAI vs LuLu comparison](https://hisnlabs.com/en/blog/fireai-vs-lulu) goes into more detail.

## If you want quiet blocking: Radio Silence

Radio Silence takes the opposite approach to alerts. Its website promises “No annoying pop-ups”: you add the apps you want to keep offline to a list, and they are blocked from the internet, while a network monitor shows which apps are connecting. It is a one-time purchase of $9, with a free trial and a 30-day money-back guarantee, and version 3.4 runs on macOS 10.15 or later on both Apple silicon and Intel Macs. It suits people who already know which apps they want silenced and do not want to be asked about the rest.

## If you think in addresses and ports: Murus

Murus is a front end to pf, the packet filter that ships with macOS. Instead of writing pf configuration files by hand, you build rules in a graphical interface. Murus Lite is free for non-commercial use and covers inbound filtering and logging; outbound filtering starts with Murus Basic at $10, and Murus Pro costs $25. Because pf works on addresses and ports, Murus rules are not tied to a particular app, which suits network-minded users and shared or server-like Macs more than someone who wants to know which app is talking. Murus 2.7 requires macOS 10.14.4 or later. Our [article on pf](https://hisnlabs.com/en/blog/macos-pf-firewall-limits) explains the trade-offs of the packet-filter approach.

## If you want an app firewall at a low price: Vallum

Vallum, sold on the Murus website as part of the same product family, works at the application layer instead. It filters both inbound and outbound connections per app and shows a pop-up alert when an app without a rule tries to connect. It costs $15 for one licence or $20 for a five-licence family pack, offers a 15-day free trial, and version 5.1 requires macOS 11.2 or later, as a universal binary; a 6.0 version is in beta. The Murus Pro Bundle, $40 for one licence, includes both Murus Pro and Vallum.

## If you want depth and fine control: Little Snitch

Little Snitch, from Objective Development, shows a connection alert when an app tries to connect, and adds a Network Monitor with a world map, blocklists, encrypted DNS (DNS over HTTPS, TLS and QUIC), rule profiles and a command-line interface. Version 6.5 supports macOS 14 Sonoma through macOS 27. A single licence is €59 as a one-time purchase, with Family licences for up to five computers. Without a licence it runs as a demo for three hours at a time and can be restarted. Our [FireAI vs Little Snitch comparison](https://hisnlabs.com/en/blog/fireai-vs-little-snitch) covers the differences in detail.

## If AI agents and uploads are your concern: FireAI

FireAI is HisnLabs’ own product, so its description here is limited to what its documentation states. It is an outbound application firewall built on Apple’s Network Extension content filter, identifies apps by code signature, and asks you the first time an app tries to reach a destination without a rule, with durations from “just this once” to “always”. It recognises 19 AI agents and, after a three-day learning period, flags an agent’s first-ever destination and unusual upload volume; in its Agent profile mode new destinations are blocked until allowed. The World map flags a country as an upload spike when it suddenly receives far more data than usual. It enforces inbound rules but never prompts for incoming connections, so Apple’s firewall remains useful alongside it. It costs €49 once for personal use, with a 17-day trial and no card required.

> **Note:** Running two outbound firewalls at once is rarely a good idea: both will ask about the same connections, and their rules can contradict each other. Pairing one outbound tool with the built-in macOS firewall for inbound connections is the usual combination.

## A short decision guide

- You only want to stop unsolicited incoming connections: turn on the macOS firewall and stealth mode.
- You want to see and decide every outbound connection, at no cost: LuLu.
- You want certain apps kept offline without being asked about the rest: Radio Silence.
- You want address and port rules on top of pf: Murus.
- You want per-app inbound and outbound alerts at a low one-time price: Vallum.
- You want an established tool with deep monitoring, blocklists and profiles: Little Snitch.
- You run AI agents or want upload spikes and new destinations flagged: FireAI.

Whichever you choose, the deciding factors are the same: which direction you need to control, whether you want to be asked, and whether rules should follow apps or addresses. For a wider view that also covers antivirus software, see our [comparison of Mac security tools](https://hisnlabs.com/en/blog/mac-security-tools-comparison-fireai).

> If outbound control and AI agents are what you need, try FireAI free for 17 days, no card needed, alongside the macOS firewall. [Download FireAI for Mac](https://hisnlabs.com/en/download)

## How FireAI and HisnLabs fit in

Every tool above answers a different question. If yours is “where are my apps and AI agents sending data?”, FireAI is free to try for 17 days, no card needed.

FireAI is HisnLabs’ own product: an on-device AI firewall for Mac. It shows every connection your apps make, in plain language, and lets you decide what leaves your Mac — its AI runs locally, so your traffic is never sent to us or anyone else. HisnLabs’ security research team is the group that keeps that decision-making accurate: cataloguing which domains are ordinary telemetry versus a real product, tracking the country and network behind a connection, and training the on-device model (its FireAI Pilot feature) on real traffic patterns, all without any of it leaving your Mac.

You can read the technical decisions behind it, or try FireAI for 17 days, at [FireAI, by HisnLabs](https://hisnlabs.com/en/download).

## Sources

- [Apple macOS User Guide: Block connections to your Mac with a firewall](https://support.apple.com/guide/mac-help/block-connections-to-your-mac-with-a-firewall-mh34041/mac)
- [Apple Platform Security: Firewall security in macOS](https://support.apple.com/guide/security/firewall-security-in-macos-seca0e83763f/web)
- [Objective-See: LuLu (product page)](https://objective-see.org/products/lulu.html)
- [LuLu source code and documentation (GitHub)](https://github.com/objective-see/LuLu)
- [LuLu 4.5.1 release notes](https://github.com/objective-see/LuLu/releases/tag/v4.5.1)
- [Radio Silence: official site](https://radiosilenceapp.com/)
- [Murus: product page, editions and prices](https://www.murusfirewall.com/murus/)
- [Vallum: product page, prices and requirements](https://www.vallumfirewall.com/index.php)
- [Objective Development: Little Snitch (product page and features)](https://www.obdev.at/products/littlesnitch/index.html)
- [Objective Development: Little Snitch download, macOS compatibility and demo terms](https://www.obdev.at/products/littlesnitch/download.html)
- [Objective Development: shop, licence types and prices](https://www.obdev.at/shop/)
- [FireAI: pricing and the 17-day trial](https://hisnlabs.com/en/pricing)
- [FireAI docs: how the network filter works](https://hisnlabs.com/en/docs/how-the-network-filter-works)
- [FireAI docs: answer your first connection prompt](https://hisnlabs.com/en/docs/answer-your-first-connection-prompt)
- [FireAI docs: Agent profile](https://hisnlabs.com/en/docs/agent-profile)
- [FireAI docs: requests by country and upload spikes](https://hisnlabs.com/en/docs/requests-by-country-and-upload-spikes)