Fully Open-sourced Online MIDI Editor

Start creating music without installing anything

Supported desktop browsers:
Google Chrome / Firefox / Safari

Want offline version?

Mac App Store


Fully equipped MIDI editor
Orchestrate freely with the multi-track piano roll editor. Of course, you can use velocity, pitch bend, expression, and modulation to create expressive sound.
Supports SoundFonts
With our specially developed high-performance sound module, you can load your sound fonts and play sounds seamlessly.
Ultra-fast audio file export
You can save the music you create as a WAV file and listen to it on your smartphone, use it as background music for your videos, or import it into your DAW.
MIDI I/O Support
Using a browser that supports the Web MIDI API, you can record the performance of a MIDI keyboard connected to your computer, or play sounds from a hardware synth.
Non-4/4 time signature and 300+ bpm
You can freely change the tempo and time signature anywhere in the song using the graph editor.
PWA support
Want to hide the browser's address bar? You can install it on your desktop and use it as an app.

Become a sponsor

signal is an app I made on weekends for fun. If you like the concept of a lightweight composition software that runs in the browser, please support me.
Open GitHub Sponsors


@signalmidiFollow us on Twitter for updates
ryohey/signalSubmit bug reports and feature requests on GitHub