Get MIDI Toolkit working.

Getting started

1. Open MIDI Toolkit. Every MIDI input your Mac can see is listed in the Monitor sidebar, and it starts listening straight away.
2. Choose which inputs to watch. Tick or untick each input in the sidebar. Messages from ticked inputs appear in the log.
3. Send something. Press ⌘2, pick a destination in the sidebar, then click the keyboard or type A–K.
4. Make a route. Press ⌘3 and click a cell in the grid to connect an input to an output. Right-click a route to edit or delete it.

Testing without MIDI hardware

You don't need any gear to try MIDI Toolkit. Either use its own virtual ports, “MIDI Toolkit In” and “MIDI Toolkit Out”, which other apps can send to and listen to, or turn on the IAC Driver that comes with macOS:

1. Open Audio MIDI Setup (in Applications › Utilities).
2. Choose Window › Show MIDI Studio.
3. Double-click IAC Driver and tick Device is online.
4. Back in MIDI Toolkit, “IAC Driver Bus 1” appears as both an input and an output. Send to it from the Send screen and watch it arrive in the Monitor.

Troubleshooting

Nothing shows up in the Monitor

• Check that the input is ticked in the Monitor sidebar.
• Make sure monitoring isn't paused. The status bar says Listening or Paused; press ⇧⌘P to switch.
• Check the filter chips above the log. Click All to show every type.
• Clear the search field. Searching hides messages that don't match.

The log is flooded with clock messages

Tick Hide clock above the log. It hides Timing Clock (F8) and Active Sensing (FE), which some devices send many times a second. They're still received and routed.

A note is stuck on

Press ⌘. for All Notes Off. It releases held notes and sends All Notes Off on all 16 channels to the current destination.

A route doesn't seem to deliver

• Make sure the route is ticked in the Routing sidebar and that routing isn't bypassed (⇧⌘B).
• Select a routed message in the Monitor. Its inspector shows whether each output received it.
• Check the route's channel and message-type settings in the Routing inspector. A filter may be blocking the type you're sending.

A device doesn't appear

Unplug it and plug it back in, then check it shows in Audio MIDI Setup. If macOS can't see it, MIDI Toolkit can't either. Some devices need their maker's driver installed first.

Note names are an octave off

Different apps call note 60 either C3 or C4. Choose the one your other software uses in MIDI Toolkit › Settings › Note names.

Keyboard shortcuts

Requirements

• macOS 26 Tahoe or later. Built and tested on macOS 27 Golden Gate.
• Any MIDI device or app your Mac recognises, or none at all if you use virtual ports.

Contact

Email us with your macOS version, MIDI Toolkit version (MIDI Toolkit › About) and what you were trying to do. A screenshot helps.