MIDI-NOXMIDI utility for Mac
FOR MAC · APPLE SILICON & INTEL

MIDI-NOXSee, route and send every MIDI message.

MIDI-NOX is a MIDI monitor, patch bay and SysEx librarian in one native Mac app. Watch everything your keyboards, synths and controllers send, connect any input to any output with transforms, and send patch banks to your instruments in one click.

Coming soon to the Mac App Store Read the guide
Native SwiftUI & CoreMIDISysEx without promptsRoutes keep running in the backgroundNo accounts, no tracking
MIDI-NOX app icon
The MIDI-NOX main window: devices on the left, the live stream of MIDI messages in the middle, the inspector on the right and a piano keyboard at the bottom

What it does

See everything

A live stream of every message from every input, decoded in plain language: "C4 vel 96", "Mod Wheel 64", manufacturer names for SysEx. Filter by type, channel, device, controller, note range or velocity.

Inspect every byte

Select a message and the Inspector explains it field by field, with every raw byte and what it means. Switch the stream to hex whenever you want the raw view.

Route anything

A patch bay and a matrix: connect any input to any output. Each route can transpose, scale velocity, remap controllers, force a channel or filter notes, channels and message types.

Presets for every setup

Save the whole routing under a name and switch setups in one click. Presets find your devices by name as well, so they work after replugging and on another Mac.

SysEx librarian

Keep your .syx banks with the synth they belong to. Brand and model are detected from the file, tags keep things findable, and an adjustable gap suits older instruments.

Send and play

Send notes, controllers, program changes with bank select, pitch bend and raw SysEx. Play the on-screen keyboard with the mouse or your computer keys. PANIC is always one click away.

A closer look

The Patch view of the routing window, with lines from inputs to outputs and the route transform editor
Patch view: click a port, then the ports on the other side. Each route can have its own transforms.
The Matrix view of the routing window
Matrix view: every input against every output, with forced output channels.
The SysEx Librarian listing banks with brand, model, tags and device
SysEx Librarian: every bank remembers its synth.
The main window in light appearance with a SysEx message in the Inspector
Light or dark: MIDI-NOX follows your Mac or the appearance you choose.

Your data stays yours

MIDI-NOX has no accounts, no analytics, no tracking and no ads, and it makes no network connections. Your routing, presets, port names and SysEx library stay on your Mac.

Read the Privacy Policy →

Need help?

The guide covers every feature, from the first route to bank dumps. If something doesn't work, get in touch and I'll help.

Open the guide →   Contact support →

Also in your browser

MIDI-NOX started as a web app, and it still runs in Chrome and Edge at midinox.cc, with nothing to install. The Mac app adds direct CoreMIDI access, SysEx without permission prompts, and routing that keeps running with every window closed.