MIDI monitor for Mac
The usual answer is MIDI Monitor by Snoize, a free, open-source Mac app that shows the MIDI going in and out of your Mac. If you would rather install nothing, a browser MIDI tester shows the same notes and knobs in Chrome, Edge or Firefox, and Audio MIDI Setup has a simple test built in. Each one answers a slightly different question, so this page says which to reach for.
I make InputConfig, a free Mac app with a MIDI view of its own, and the MIDI tester on this site. I list Snoize's app first because it is the dedicated tool.
On this page: 8 sections
Steps
- Decide what you need to know: whether the Mac hears the device, what exactly it sends, or what an app sends out.
- For a quick check with nothing installed, open the MIDI tester in Chrome, Edge or Firefox and play.
- For a full log, including what other apps send, download MIDI Monitor from Snoize.
- For a yes or no from macOS itself, use Test MIDI Setup in Audio MIDI Setup's MIDI Studio.
- To see MIDI and map it to shortcuts in one place, open InputConfig's Live Visualizer.
Pick the monitor for the question
| You want to know | Use |
|---|---|
| What every message is, in a log you can save | MIDI Monitor by Snoize |
| What another app is sending out | MIDI Monitor by Snoize |
| Whether a key, pad or knob works, right now, with nothing installed | A browser MIDI tester |
| Whether macOS itself hears the device | Test MIDI Setup in Audio MIDI Setup |
| What a control sends, so you can give it a shortcut | InputConfig's Live Visualizer |
For a full record of the traffic, use Snoize's app, and for a quick look, use the browser.
InputConfig is free on the Mac App Store. macOS 14 or later, no account, no tracking, open source.
MIDI Monitor by Snoize
Snoize describes it as an app to display MIDI signals going in and out of your Mac, for musicians tracking down MIDI problems and for programmers testing MIDI software.
- Price and license. Free to download and use, with the source code open under the BSD license.
- Version. 1.5.4, from July 2023, which needs macOS 10.13 or later.
- What sets it apart. It can watch the output of other apps, not only hardware coming in.
It is the only one of the four that watches another app's output directly. Its page is snoize.com/midimonitor.
A MIDI tester in the browser
- You: Open the MIDI tester in Chrome, Edge or Firefox, press Start listening and allow MIDI.
- The page: Lists every message with its channel, lights each note on an 88-key drawing, and shows velocity, knobs as CC numbers, pitch bend and the tempo from MIDI clock.
- Check: Play every key once. A key that stays unlit never sent a note.
Nothing is installed and nothing leaves the page, which makes it the fastest first check. Safari has no MIDI for web pages, so it needs one of the other three browsers. The Sound button plays a tone for each note.
The test built into macOS
Open Audio MIDI Setup, choose Window, Show MIDI Studio, and click Test MIDI Setup in the toolbar. Play a note, and the up arrow on the device's icon lights. Click a device's down arrow, and the Mac sends it a MIDI signal. It shows that a message arrived, not what the message was.
It is the check to trust when you need to know whether the fault is in the Mac or in an app.
InputConfig's Live Visualizer
InputConfig's MIDI layout shows a seven-octave keyboard shaded by velocity, a named dial for every knob, pitch bend and aftertouch meters, a channel strip and an event log. It is built for finding out what a control sends so you can bind it: press Scan on a row, move the control, and the row is set.
Use it when the point of looking is to turn that pad or knob into a shortcut. MIDI to keystroke on a Mac has the setup.
The short version
- The dedicated app. MIDI Monitor by Snoize, free and open source.
- Nothing to install. A browser MIDI tester.
- From Apple. Test MIDI Setup in Audio MIDI Setup.
- To map what you see. InputConfig.
All four are free, so use the one that answers your question.
Questions
Is there a free MIDI monitor for Mac?
Yes. MIDI Monitor by Snoize is free and open source. A browser MIDI tester needs no install, and Audio MIDI Setup, which comes with macOS, has a basic test.
Does macOS have a built-in MIDI monitor?
It has a test, not a full monitor. In Audio MIDI Setup's MIDI Studio, Test MIDI Setup lights an arrow on a device when a message arrives, without showing what the message was.
How do I see MIDI messages on a Mac?
Open a browser MIDI tester in Chrome, Edge or Firefox for a quick look, or install MIDI Monitor by Snoize for a full log of every message in and out.
Can I monitor MIDI in Safari?
No. Safari does not offer MIDI to web pages. Use Chrome, Edge or Firefox for a browser tester, or an app such as MIDI Monitor.
How do I see what MIDI an app is sending?
MIDI Monitor by Snoize can watch the output of other apps. The other three tools on this page show incoming MIDI from devices.
Related
Free. macOS 14 or later. No account, nothing leaves your Mac. Open source on GitHub.
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