MIDI Editor Online — Free Browser-Based Piano Roll

What is MIDI?

MIDI (Musical Instrument Digital Interface) is a decades-old standard for representing music as a sequence of events rather than recorded audio. Instead of capturing sound waves, a MIDI file records what notes were played, when they started, how long they lasted, and how hard they were hit. This makes MIDI files tiny, perfectly editable, and playable by any synthesizer — from a hardware keyboard in 1985 to a browser in 2026.

A typical MIDI file contains one or more tracks, each carrying a stream of note events, an instrument assignment, a channel number, and optional metadata like tempo and time signature. Because the actual sound is rendered at playback time, the same .mid file can sound completely different on a grand piano synth versus a distorted guitar patch.

Modern use cases for MIDI include composition and arrangement inside a DAW, game music (chiptune, orchestral scores), educational tools, music theory experimentation, AI-generated music prompts, and notation software. If you have ever seen a piano roll scrolling across the screen while a song plays — that is MIDI.

How to Edit MIDI Files Online

1. Open a file — click Open MIDI File or drag a .mid file anywhere on this page. You can also click Create Blank Project to start from nothing.
2. Pick a track — the left sidebar shows all tracks. Click one to make it active; new notes go into the active track.
3. Select a tool — the toolbar gives you Pencil (add notes), Select (multi-select, move, transpose), Eraser (delete), and Velocity (change how loud a note is).
4. Draw and edit — click on empty cells to add notes, drag note bodies to move them, drag the right edge to resize. Hold the mouse button to draw a custom-length note.
5. Play it back — click the Play button in the transport bar. The first click loads the audio engine and starts playback. Adjust tempo, volume, and loop region while it runs.
6. Export — click Export to download the result as a standard .mid file that any DAW can open.

All editing is fully undoable with Ctrl/Cmd+Z. Your work auto-saves to your browser so you can come back later without losing progress.

MIDI Editor Features

This free MIDI editor runs entirely in your browser and includes everything you need to create, edit, and export MIDI files.

Who Uses a MIDI Editor?

MIDI editors are used across music production, education, game development, and creative coding.

• Music producers and composers sketch melodies, build chord progressions, and arrange multi-track compositions before committing to a full DAW session.
• Beginners and students learn music theory by visualizing notes on the grid. Seeing intervals, chords, and scales laid out spatially builds intuition faster than notation alone.
• Game developers create adaptive soundtracks and chiptune music. MIDI files are tiny and can be rendered at runtime with different instruments, making them ideal for interactive media.
• Music teachers prepare exercises, demonstrate concepts, and share editable MIDI files with students who can open them in any editor or DAW.

Piano Roll Basics

A piano roll is a grid where horizontal position represents time and vertical position represents pitch. Each note is drawn as a rectangle: its x-position is when the note starts, its y-position is the pitch, its width is the duration, and its opacity reflects the velocity (how hard the key was hit). The column of piano keys on the left is a visual reference — click any key to hear that pitch through the current track's synth.

MIDI vs Audio Files

Use MIDI while you are composing — it gives you maximum flexibility. Render to audio only at the end for distribution.

Keyboard Shortcuts