midee - free online MIDI player and Synthesia alternative
midee is a free, open-source online MIDI player, visualizer, and practice app that runs entirely in your browser. Drop a .mid
file and it plays on a full 88-key piano roll with cascading notes, glow halos, and particle bursts - a
Synthesia-style piano-roll visualizer, but web-native, design-forward, and free.
It's also a live MIDI instrument and a simple loop station. Plug in a MIDI keyboard (Web MIDI), or play from
your laptop keyboard, and jam. Loop a phrase bar-snapped to the metronome, layer takes, record a session, and
export the result as a frame-accurate 1080p MP4 with audio baked in.
midee requires JavaScript. Please enable JavaScript to use the app.
What midee does
- Play MIDI files in the browser - multi-track, per-track color, full 88 keys.
- Live MIDI play from Web MIDI controllers or your laptop keyboard (FL Studio layout).
- Learn mode - play-along wait mode, sight reading, interval training, accuracy, streaks, and weak-note practice.
- Loop station - bar-snapped to the metronome, layerable, undo stack, export as .mid.
- Session recording - capture a live performance and bounce to .mid or video.
- MP4 export - 720p, 1080p, vertical (TikTok, Reels), square, or native. Frame-accurate,
audio baked in, rendered locally via WebCodecs.
- Themes, instruments, particles - five themes, sampled piano plus multiple synth and acoustic
voices, cycleable particle styles.
- Free and open source - MIT-licensed, 100% client-side, no upload, no account, no watermark.
Who midee is for
Bedroom producers who want a quick piano-roll video for a Reel or YouTube Short. Piano learners who want to
visualize a new piece. Classical music fans who want to turn a MIDI from the Mutopia project into a shareable
clip. MIDI keyboard owners who want something beautiful to look at while they jam, without firing up a full DAW.
How midee compares
If you've looked at Synthesia (native piano learning), SeeMusic (paid video
visualization), sightread.dev (focused browser practice), or MIDIano /
midi2vidi (simple MIDI tools), midee is the web-native, open-source alternative - with MIDI
playback, live mode, Learn mode, looping, recording, and frame-accurate MP4 export in one place.
Common questions
Is it really free? Yes. MIT-licensed. No account, no paywall, no watermark.
Does my MIDI get uploaded? No. Everything runs in your browser. Your .mid and the rendered MP4
never leave the machine.
Can I use my MIDI keyboard? Yes - any Web MIDI-compatible controller works. Your laptop
keyboard works too.
What do I need to run it? A recent Chromium browser (Chrome 94+), Safari 16.4+, or Firefox
130+. Desktop recommended; iPad works; phone is limited.
Read more
Open source on GitHub - contributions welcome.