MIDI Loupe allows you to monitor and log MIDI messages from one or multiple MIDI devices. It is mostly useful for debugging and testing your MIDI setup, if something goes wrong.

Every registered MIDI Source is listed and has a separate color, so you can easy differentiate between the messages. In the device list you can select/deselect the devices for logging.
You can save the logs to disk and also load them for later inspection.

Please also look at for more informations.

What’s New

Version 1.5

- user now can switch between note, decimal or hexadecimal values in the monitor view
- fix: respects "stay on top" setting after app start
- fix: note on/off messages now correct
- small OS-X Sierra fixes

Ratings and Reviews

2.5 out of 5
8 Ratings

8 Ratings

chrisrimple ,

Works well on High Sierra

It’s working well for me on High Sierra with an iConnect Mio usb-to-MIDI interface. I tested with two MIDI devices, a Rock Band 3 Wii Keytar and a Yamaha P-80 Electric Piano. Both devices are sending a continuous stream of unnecessary messages, which is annoying - the Yamaha sends an “[RT Clock]” update every few milliseconds, which fills the app message window with MIDI messages that I don’t care to see. That leads me to a feature request: provide a way to filter out undesired messages, using string matching or similar. Similarly, allow “unknown” messages to be hidden, so that the user only sees messages that can be identified by the app.

jack382 ,

Doesn’t run on High Sierra

Reinstalled multiple times but every time it won’t even start.

Wisdarch ,

Just what I was looking for

People seem to have had issues with High Sierra since the last time this was updated, but I'm running Mojave and I haven't had any issues.


Gerald Flossmann
2.2 MB

OS X 10.8 or later, 64-bit processor



Age Rating


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.