Midilize – real-time MIDI monitor & router for macOS (debugging + scripting)

[Royant]

Debugging MIDI on macOS has always felt a bit opaque to me — especially when trying to trace messages between apps or figure out why something is misbehaving, I kept running into stuck notes with no clear source, unexpected messages coming from plugins/devices, messy routing between apps using IAC / virtual ports, midi loops etc.

So I built a tool to make MIDI behavior actually visible and easier to work with.
Midilize is a standalone macOS app that lets you monitor all MIDI messages in real time, route signals between apps/devices visually process/filter data (including custom scripts).

The main idea is to have everything in one place instead of juggling multiple tools.
Here’s a quick example:

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It’s currently free while in beta.
I’d really appreciate feedback — especially from anyone dealing with more complex MIDI routing setups or debugging issues.

https://www.midilize.com

[Morty-C-137]

Midi to keyboard shortcuts also?

[Royant]

Midi to keyboard shortcuts also?

Yes!

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[Morty-C-137]

Awesome!

[Morty-C-137]

I am trying the beta right now and it's very good. Would be great if we could rename our virtual outputs so that in our DAW's we can recognize what we are connecting to (midi controller wise).

Getting some intermitting note hangs running current setup:

[Royant]

Thanks for the feedback.

I’m currently improving the renaming experience. For now, you can rename ports by going to the Monitor tab, clicking the blue Inputs/Outputs button, then double clicking the port name to edit it. I know this isn’t ideal, the next build in a couple of days will be much better.

Also, could you please use the “Feedback” button in the app to report the issue with note hangs? It sends logs from the app, which will help me debug and fix the problem.
Thanks!

[Morty-C-137]

Cheers! Will do.

[Morty-C-137]

Just coming back here to say I am LOVING the new additions where you can live monitor the notes, scale and chords right in the monitor section.

The only thing I could which for there is to a bigger view of the chord & scale section.

[Royant]

Glad you like it!

Have you tried with an MPE controller?

Will see if I can make the key/chord section bigger.

[Morty-C-137]

Awesome! I don’t have an MPE capable controller so can’t speak to that.

[Morty-C-137]

Loving the latest build! Still keen on seeing a larger display for Chord and Key info.

Would it make sense to add plugin hosting capabilities to this? To me that feels like a logical evolution and a hell yes. But I understand that would maybe drag to much into this and also resources to make.

[Royant]

Glad like you like it! Larger display is coming, promise!

Regarding plugin hosting, very possible in the future, mostly concerned about UX and make it right.

[Royant]

I wanted to share a video by Nay Seven, who’s doing some really impressive and creative work with Midilize!

[Mantras]

Does this share some functionality with Bome Midi Translator pro? For instance can I merge midi inputs to a virtual midi port?
Or translate a #cc message on one channel to another #cc message to another channel?

[nay-seven]

yes for both:

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