About MidiGlow

MidiGlow is a free online MIDI file player and visualizer. Drop a .mid or .midi file into the page and it plays within seconds — with tempo control, A-B looping, per-track mute and solo, and a glowing falling-notes piano roll that stays perfectly in sync with the music. When a passage looks as good as it sounds, you can record the performance and export it as a video, right in the browser. No account, no download, no setup.

Local-first by architecture

What makes MidiGlow different is where the work happens: entirely on your device. There is no server-side processing anywhere in the pipeline. Opening a file hands its bytes to a parser running inside your browser tab; the music is synthesized in real time with the Web Audio API; the visualization is drawn on an HTML Canvas, frame by frame, timed by the same audio clock that plays the notes; and video export uses the browser's built-in MediaRecorder. Your MIDI files are never uploaded, never stored, and never seen by anyone else — refresh or close the tab and the session is simply gone.

A small, fast static site

MidiGlow is deliberately built as a lightweight static site — plain HTML, CSS and TypeScript, with no heavy framework runtime on the first screen — so the tool loads fast and is usable immediately. It is free to use, with no ads, no paywall, and no feature locks.

Why it exists

Playing a MIDI file shouldn't require installing a DAW or signing up for a service. Whether you're slowing down a difficult passage to practice it, checking an arrangement track by track, or just want to watch your music glow, MidiGlow aims to be the fastest way from "I have a .mid file" to hearing and seeing it.

Try the MIDI player online or the MIDI visualizer — or head back to the homepage and drop in a file.