LuLu vs Radio Silence
Which is the better firewall for Mac in 2026?
LuLu
Open-source firewall to block unknown outgoing connections
Radio Silence
Network monitor and firewall
Our verdict
How we compare appsThere is no single score. LuLu 4.5.1 is the free open-source tool with prompts and a remote-address rule. Radio Silence 3.4 is the $9 tool that blocks whole apps, skips pop-ups, and shows a real-time connection list. The scores above are the word Unscored on purpose.
Read the quick answer
Which is better: LuLu or Radio Silence?
LuLu and Radio Silence are both firewall on a Mac, so the pick depends on workflow. Install LuLu when you want the source and a host rule at no charge. Buy Radio Silence when a quiet whole-app block list is the job. As of October 2026, both install with brew install --cask lulu and brew install --cask radio-silence.
TL;DR
LuLu vs Radio Silence: There is no single score. LuLu 4.5.1 is the free open-source tool with prompts and a remote-address rule. Radio Silence 3.4 is the $9 tool that blocks whole apps, skips pop-ups, and shows a real-time connection list. The scores above are the word Unscored on purpose.
Feature Comparison
| Feature | LuLu | Radio Silence |
|---|---|---|
| Price | Free | Free |
| Open Source | No | No |
| Replaces | Little Snitch ($65) | — |
| Best for | firewall, network, privacy | radio silence |
| Install | brew install --cask lulu | brew install --cask radio-silence |
| Category | Security & Privacy | System Utilities |
Quick Install
brew install --cask lulubrew install --cask radio-silenceLearn More
In-Depth Overview
LuLu: free prompts and host rules
Objective-See describes LuLu as a free, open-source firewall that blocks unknown outgoing connections. The download line is v4.5.1 for macOS 10.15 or later. GitHub lists Version 4.5.1 as Latest, timestamp 2026-08-05. An alert appears for a new unauthorized outgoing connection. The default decision becomes a general rule for the process. You can also add a rule by entering a remote address or domain and a remote port. Profiles were added in v4.0 and later. Passive mode runs silently, applies existing rules, and lets you choose whether new connections are allowed or denied. The Network Monitor menu opens Netiquette, which is packaged into LuLu. A VirusTotal button on the alert opens that file's result page.
Radio Silence: quiet whole-app blocking
Radio Silence blocks any app from phoning home, shows every network connection in real time, and exposes helpers, daemons and XPC services. Child processes of blocked apps are automatically blocked. There are no annoying pop-ups. The buy button reads Buy now for only $9. There is a free trial and a 30-day money-back line. Requirements: macOS 10.15 or newer, Apple Silicon and Intel, and macOS Golden Gate. The download page lists Version 3.4 for macOS 10.15 and newer. Its 3.4 notes mention installation guidance for macOS Tahoe. No calendar date is printed for 3.4.
Detailed Feature Comparison
Price and trial
High importanceLuLu
DocumentedLuLu is free. There is no paid tier.
Radio Silence
Documented$9. Free trial. 30-day money-back guarantee.
Verdict: LuLu costs nothing. Radio Silence is $9 with a trial and a 30-day refund.
Source code
High importanceLuLu
DocumentedOpen source, with the source code linked from the product page.
Radio Silence
Not statedSource code is not published.
Verdict: Only LuLu's page states that the firewall is open source.
How a block is scoped
High importanceLuLu
DocumentedDefault rule is for the whole process. A manual rule can set a remote address or domain and a remote port.
Radio Silence
DocumentedYou block an app. Child processes of blocked apps are blocked too. Radio Silence does not describe a per-host allow rule.
Verdict: LuLu documents a host or domain field. Radio Silence documents a whole-app block.
Prompts
High importanceLuLu
DocumentedAlerts on new unauthorized outgoing connections. Passive mode can run without alerts.
Radio Silence
DocumentedNo annoying pop-ups is a headline product property.
Verdict: LuLu asks, unless you turn on Passive mode. Radio Silence is built not to ask.
Monitor
Medium importanceLuLu
DocumentedNetwork Monitor menu launches the packaged Netiquette app for current network activity.
Radio Silence
DocumentedThe network monitor shows every connection in real time, including helpers and XPC services.
Verdict: Both show current connections. Neither app describes a multi-month history chart.
Current build
Medium importanceLuLu
DocumentedDownload v4.5.1, macOS 10.15+. GitHub Latest timestamp 2026-08-05.
Radio Silence
DocumentedDownload page: Version 3.4, macOS 10.15+. Release notes mention macOS Tahoe guidance. No calendar date is printed.
Verdict: Both vendors publish a current Mac build.
Who Should Choose Which?
1Wants a free prompt firewall
LuLu 4.5.1 is free and open source, alerts on new outgoing connections, and can store a process rule or a remote address rule.
2Wants specific apps offline and no prompts
Radio Silence 3.4 is $9, blocks the app and its child processes, and shows no pop-ups.
3Wants to see helpers and XPC services
Radio Silence's monitor exposes helpers, daemons and XPC services in real time.
4Wants to allow an app but deny one domain
A LuLu rule takes a remote address or domain and a remote port. Radio Silence blocks the app.
Migration Guide
Lulu → Radio Silence
Neither vendor documents a rule import from LuLu into Radio Silence. Uninstall one network extension before you rely on the other. Then rebuild the short list of apps you want offline inside Radio Silence.
Radio Silence → Lulu
Neither vendor documents a Radio Silence import into LuLu. After LuLu is the only filter, expect alerts for apps that Radio Silence had left allowed, and recreate any host rule by hand.
Pro Tips
Do not treat a Radio Silence app block as a LuLu domain rule, or the reverse. Write down the apps you blocked before you switch.
Final Verdict
Depends on the job
Score
LuLu
Score
Radio Silence
Scores are Bundl.run editorial ratings out of 10 across 6 criteria (the feature comparison above), last reviewed August 2026.
There is no single score. LuLu 4.5.1 is the free open-source tool with prompts and a remote-address rule. Radio Silence 3.4 is the $9 tool that blocks whole apps, skips pop-ups, and shows a real-time connection list. The scores above are the word Unscored on purpose.
Bottom Line: Install LuLu when you want the source and a host rule at no charge. Buy Radio Silence when a quiet whole-app block list is the job.
Frequently Asked Questions
Is LuLu or Radio Silence free?
Which one asks before a new connection?
Can either app block a single domain?
What versions were current on 2026-10-14?
Do the vendors publish memory use?
About the Author
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Sources & References
Last verified: Oct 14, 2026
Key Verified Facts
- LuLu 4.5.1 is a free open-source firewall for macOS 10.15 or later, and a rule can name a remote address or domain plus a remote port.[1]
- GitHub lists LuLu 4.5.1 as Latest with timestamp 2026-08-05.[2]
- Radio Silence is $9, with a free trial, a 30-day money-back guarantee, no pop-ups, and automatic blocking of child processes.[3]
- Radio Silence's download page lists Version 3.4 for macOS 10.15 and newer.[4]
- 1objective-see.orgLuLu by Objective-See
Accessed Oct 14, 2026
Source excerpt
Free, open-source firewall. Download v4.5.1, macOS 10.15+. Remote address or domain and remote port on a rule. Passive mode. Network Monitor opens Netiquette.
- 2github.comLuLu releases on GitHub
Accessed Oct 14, 2026
Source excerpt
Version 4.5.1 Latest. Release timestamp 2026-08-05T12:53:15Z.
- 3radiosilenceapp.comRadio Silence homepage
Accessed Oct 14, 2026
Source excerpt
Buy now for only $9. Free trial. 30-day money-back. No annoying pop-ups. Child processes of blocked apps are automatically blocked. macOS 10.15 or newer.
- 4radiosilenceapp.comRadio Silence download
Accessed Oct 14, 2026
Source excerpt
Version 3.4, requires macOS 10.15+. Release notes: installation guidance for macOS Tahoe.
Research queries: lulu vs radio silence