No new version for more than 90 days, so OpenNavo has paused recommending and installing it. Homebrew still offers this app.

MIDI Monitor

A macOS app for viewing MIDI signals entering and leaving your Mac, useful for troubleshooting and testing MIDI software and drivers.

CaskAudio ProductionAuto-updatesApple silicon · IntelPaused by OpenNavo

Homepage

From homebrew/cask

30-day installs: 55
1-year installs: 603; Last 365 days
Latest version: 1.5.4; Jul 21, 2023 · Jul 21, 2023
Download size: 10MB; arm64 / x86_64 · dmg
Release cadence: Irregular; 0 releases in 30 days

MIDI Monitor is a Audio Production app for Mac.

Quick facts

Chips: Apple silicon · Intel
Install: brew install --cask midi-monitor
Homebrew: Still offered by Homebrew; paused by OpenNavo
Also known as: midi-monitor

These facts were checked on or after Oct 21. See each source

About

MIDI Monitor is a macOS application for viewing MIDI signals going in and out of your Mac. Musicians can use it to investigate MIDI problems, while programmers can use it to test MIDI drivers and applications. It is a graphical app, not a command-line tool.

Displays incoming and outgoing MIDI signals.
Can help track down confusing MIDI problems and test MIDI drivers or applications.
Shows detailed event data in a dedicated view; the site notes that this data can be copied as hexadecimal bytes or text.
Includes a feature for observing another app’s MIDI output. The official site reports that this feature had a macOS-specific limitation on versions 11.0–11.1, resolved by updating to 11.2.

Install with Homebrew Cask using brew install --cask midi-monitor. The cask installs MIDI Monitor.app in /Applications. The app requires macOS 10.13 or later. The developer describes MIDI Monitor as free to download and use; this listing is for the MIDI Monitor app, not another Snoize product.

Sources: Official MIDI Monitor page · Homebrew Cask definition

System requirements

macOS	Version	Chips	Download	Source
Build for macOS 27, 26, 15, 14, 13, 12, 11	1.5.4	Intel	www.snoize.com/MIDIMonitor/MIDIMonitor_1_5_4.dmgSHA-256 `6deea9673e2947c59ef4f2c57446366930989ea2688cc5d5b8265401a38a3971`	HomebrewChecked Oct 21
Build for macOS 27, 26, 15, 14, 13, 12, 11	1.5.4	Apple silicon	www.snoize.com/MIDIMonitor/MIDIMonitor_1_5_4.dmgSHA-256 `6deea9673e2947c59ef4f2c57446366930989ea2688cc5d5b8265401a38a3971`	HomebrewChecked Oct 21

How to install MIDI Monitor on Mac

In Terminal, run: brew install --cask midi-monitor
Homebrew installs the app in your Applications folder.

Install without Homebrew

Download the same file Homebrew uses: www.snoize.com/MIDIMonitor/MIDIMonitor_1_5_4.dmg

SHA-256 only checks that the download is complete; it is not a security certification. See the SHA-256 and download address

Uninstall MIDI Monitor and optional data cleanup

Uninstall command

brew uninstall --cask midi-monitor

A regular uninstall removes the app and keeps its settings and caches.

Deep clean (optional)

Uninstall command

brew uninstall --zap --cask midi-monitor

--zap also deletes the settings, caches and other files listed in the Homebrew definition. They can include data shared with other apps and cannot be restored, and it does not guarantee that nothing is left. Back up any data you need first. To keep settings and caches, leave out --zap.

Files MIDI Monitor can leave on your Mac (5)

Files and folders: ~/Library/Application Support/com.apple.sharedfilelist/com.apple.LSSharedFileList.ApplicationRecentDocuments/com.snoize.midimonitor.sfl*; ~/Library/Caches/com.snoize.MIDIMonitor; ~/Library/HTTPStorages/com.snoize.MIDIMonitor; ~/Library/Preferences/com.snoize.MIDIMonitor.plist; ~/Library/Saved Application State/com.snoize.MIDIMonitor.savedState

These entries come from the Homebrew definition, checked Oct 21. They say what it declares, not what is on your Mac.

What’s new in 1.5.4

New Jul 21, 2023 · OpenNavo editorial

Bug fixesFixed a crash when spying on another app’s output during heavy MIDI data.

See all 1 release

MIDI Monitor security facts

Only facts that can be checked, each with its source and date. This is not a safety certification. To check the files you downloaded, scan them on your Mac with OpenNavo.

Distribution: Homebrew

Scan with OpenNavoOpens a scan preview in the OpenNavo app; you decide whether to start it. Learn about Security

Install Details

Tap: homebrew/cask
Download URL: https://www.snoize.com/MIDIMonitor/MIDIMonitor_1_5_4.dmg
SHA-256: 6deea9673e2947c59ef4f2c57446366930989ea2688cc5d5b8265401a38a3971
Homebrew definition: github.com/homebrew/homebrew-cask/blob/HEAD/Casks/m/midi-monitor.rb
formulae.brew.sh: formulae.brew.sh/cask/midi-monitor

Installation and removal contents

Uninstall uninstall

View full declaration

{
  "uninstall": [
    {
      "quit": [
        "com.snoize.MIDIMonitor",
        "com.snoize.MIDIMonitorDriver",
        "com.snoize.MIDISpyFramework",
        "com.snoize.SnoizeMIDI"
      ]
    }
  ]
}

Install app
Source file: MIDI Monitor.app
Declared destination: /Applications/MIDI Monitor.app
View full declaration
```
{
  "app": [
    "MIDI Monitor.app"
  ],
  "target": "/Applications/MIDI Monitor.app"
}
```

Remove user data zap

View full declaration

{
  "zap": [
    {
      "trash": [
        "~/Library/Application Support/com.apple.sharedfilelist/com.apple.LSSharedFileList.ApplicationRecentDocuments/com.snoize.midimonitor.sfl*",
        "~/Library/Caches/com.snoize.MIDIMonitor",
        "~/Library/HTTPStorages/com.snoize.MIDIMonitor",
        "~/Library/Preferences/com.snoize.MIDIMonitor.plist",
        "~/Library/Saved Application State/com.snoize.MIDIMonitor.savedState"
      ]
    }
  ]
}

Questions about MIDI Monitor

Is MIDI Monitor safe?

MIDI Monitor is in Homebrew’s official catalog and has not been disabled. Since September 2026, Homebrew disables apps that fail macOS Gatekeeper checks. When installing, Homebrew checks the download from www.snoize.com against its SHA-256 checksum. It was installed 55 times through Homebrew in the last 30 days.

How do I completely uninstall MIDI Monitor on a Mac?

Run brew uninstall --cask midi-monitor. It quits the app. To delete its settings and caches as well, run brew uninstall --zap --cask midi-monitor. --zap also deletes the settings, caches and other files listed in the Homebrew definition. They can include data shared with other apps and cannot be restored, and it does not guarantee that nothing is left. Back up any data you need first. To keep settings and caches, leave out --zap. That also deletes 5 files and folders, including ~/Library/Preferences/com.snoize.MIDIMonitor.plist.

Does MIDI Monitor run on Apple silicon (M1 and later) Macs?

Homebrew installs it on both Apple silicon and Intel Macs, from the same download.

Where does MIDI Monitor store its settings and data?

Its settings are in ~/Library/Preferences/com.snoize.MIDIMonitor.plist. These locations come from Homebrew’s clean-up list.

What is the latest version of MIDI Monitor?

The latest version is 1.5.4, added to Homebrew on Jul 21, 2023. MIDI Monitor updates itself; to update it with Homebrew, run brew upgrade --cask --greedy midi-monitor.

Sources

Every fact on this page names its source and check date. Facts past their validity read “as of” their date and are no longer stated as current.

Homebrew definition: github.com/homebrew/homebrew-cask/blob/HEAD/Casks/m/midi-monitor.rb · Checked Oct 21
formulae.brew.sh: formulae.brew.sh/cask/midi-monitor

Install command

brew install --cask midi-monitor

Token: midi-monitor
Homepage: www.snoize.com/MIDIMonitor
Updates: Updates itself (auto_updates)

Monthly installs

Installs are steady

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Item	Value
Last 30 days	55 installs
90-day avg	54 installs
1-year avg	50 installs