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Control protocol test utility

Monitor MIDI, OSC and more...

Prokotol is a new utility by Hexler for the creator's toolbox: A lightweight, responsive console app for monitoring and logging control protocols.

Originally built as a MIDI monitor and OSC network checker, Protokol is designed to handle any complex message stream with accuracy: MIDI, OSC and Gamepad HID input monitoring are all currently included but drop us a line if you would like to see other protocols added: IoT, DMX, ArtNET, anything is literally possible given sufficient demand.

Heavy Duty, Fast Response

Protokol renders all incoming data at 60 frames per second (with or without timestamp). This responsiveness enables you to track down critical timing issues, identify conflicts, interrupts, or just pretend you are Cypher observing the Matrix. And of course Protokol offers granular filters: Data types, messages, channels and ports.

Cross Platform

Protokol installs and runs equally well on all platforms – from a compact Raspberry Pi MIDI monitor or Linux based OSC message logger to more traditional Windows and Mac OS based music studios – same interface, same speed and same accuracy. Download your copy now!

And we have not forgotten mobile. Android and iOS versions are currently in testing at Hexler HQ with a public release coming soon.


We built Protokol as an in-house tool to test our own apps during development, and quickly found use for it in our home studios (troubleshooting MIDI hardware). A few of our music producer mates saw it and began bugging us for a copy ... so here it is.

Currently available as beta software. If you have any feature requests we'd love to hear 'em, and if you see a glitch or bug we are equally interested to know!


A responsive heavy duty console for troubleshooting control protocols.

Mac Windows Linux

Download Protokol Beta

Click the buttons above to pop up links for your specific OS: Mac, Windows, and multiple versions of Linux (ARM, Raspberry Pi, x86 etc.)

DISCLAIMER: This is an early preview version and might not function as expected. Please use at your own risk.