An IAC (Inter-App Communication) device is a virtual MIDI device that allows multiple MIDI applications on the same device to communicate with each other.


macOS comes with a built-in IAC Driver to facilitate MIDI connections between applications. See “Transfer MIDI information between apps in Audio MIDI Setup on Mac” on Apple Support for more information.

Connecting WebMIDICon through IAC Driver to Logic Pro running on the same machine:



You can install LoopBe1, a virtual MIDI device driver for Windows which is free for non-commercial use. If you need more than 1 port, you can buy the LoopBe30 device.

Connecting WebMIDICon through LoopBe1 to FL Studio running on the same machine:



You can buy Midiflow which lets you create virtual MIDI devices that other apps can use. Please note that iOS is not that great at multitasking, and from my experience, the application in the background is automatically killed by the OS after a while.

Connecting WebMIDICon through Midiflow to GarageBand running on the same iPhone: