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Personal firewall for macOS

A personal firewall for developers.

Network Monitor is for the Mac you SSH from, deploy from, and leave running. See which process opens which connection, where that server is, and allow or deny it.

Filtering runs on your Mac, in a network extension you approve in System Settings. No account. No analytics. Your rules stay on this Mac.

Live Connections grouped by app
Offline City and country, on device
15+ macOS Sequoia or later
Local Rules never leave this Mac

How it works

Three views of the same traffic.

The list, the map, and the rules stay in sync. You decide what is allowed.

  1. 1
    Watch the list

    Connections group by app: host, address, port, protocol, and the rule that applies. An inspector shows the app path and the matching rule.

  2. 2
    See the map

    Arcs run from your Mac to each server. Cities cluster by verdict: allowed, ask, or denied. Select a city to see who connects there.

  3. 3
    Allow or deny

    The first time an app connects, an alert asks you to allow or deny it — once, for 15 minutes, until quit, or forever. The most specific rule wins.

Features

A personal firewall you can actually steer.

See the traffic, place it on a map, and write the rule. Nothing is uploaded to decide a verdict.

Live connection list

Processes group their servers with name, address, port, and protocol. Search by process, host, address, or port.

World map

Server cities come from an offline database. No address is sent out to look up a location. Arcs start at your Mac.

Rules with a clear order

Match by app, host, domain, IP, network, port, and protocol. A tighter match wins. Deny wins a tie.

Answer a flood at once

One alert can cover every queued prompt the new rule already answers. Approve seen traffic turns what you have already watched into rules.

Tracker blocklists

Import hosts files, domain lists, or Adblock-format lists and deny known trackers for every app.

Three menu-bar modes

Alert asks each time. Silent Allow and Silent Deny decide without a prompt. Switch modes from the menu bar.

The app

List, map, rules, and the ask.

Demo traffic only — public services, a fixed map origin, and sample rules. No real addresses from a Mac.

Connections — Network Monitor
Connections Grouped by app, with location and the rule that applies.
Map — Network Monitor
Map Arcs from this Mac to each server, colored by verdict.
Rules — Network Monitor
Rules Allow or deny by app, host, domain, address, port, and protocol.
Alert — Network Monitor
Alert Allow or deny once, for a while, until quit, or forever.

Filter

Approve the network extension once.

The list and the map show traffic. Enforcement starts after you approve the Network Monitor filter in System Settings.

  1. Put Network Monitor in /Applications. A system extension activates from there.
  2. Open Settings → Filter → Install & Enable Filter.
  3. Approve it under System Settings → General → Login Items & Extensions.
  4. Pick a mode from the menu bar: Alert, Silent Allow, or Silent Deny.

What's new

Changelog

Release notes for Network Monitor.

  1. v1.0
    • Live connections grouped by app, with host, port, protocol, and location.
    • World map with offline geolocation and arcs from this Mac.
    • Allow and deny rules, connection alerts, and blocklist import.
    • Menu bar modes: Alert, Silent Allow, and Silent Deny.

FAQ

Network Monitor — common questions.

What it watches, where data stays, and how the filter is approved.

What is Network Monitor?

A personal firewall for devops and developers on macOS. It lists each process's connections, maps the servers, and lets you allow or deny them with rules.

Does any of this leave my Mac?

No. There is no account and no analytics. Rules and connection history stay on the Mac. Location is used only as the origin of the map arcs.

How does the map know a server's city?

From a geolocation database stored on the Mac. No IP address is sent to a third party for the lookup. IP geolocation by DB-IP, licensed under CC BY 4.0.

How do I turn filtering on?

Install the app in /Applications, then Settings → Filter → Install & Enable Filter, and approve it in System Settings → General → Login Items & Extensions.

What macOS version do I need?

macOS 15 (Sequoia) or later.

Where do I download it?

A public Mac App Store listing and a direct download are not on this page yet. The support guide and privacy policy are ready for that listing.

See the traffic. Then decide.

Read the support guide for the filter steps, and the privacy policy for what stays on your Mac.

IP geolocation by DB-IP (db-ip.com), licensed under CC BY 4.0.