The Online MIDI Editor Free Online MIDI Editor — Piano Roll, Quantize, No Install Edit .mid files with studio-grade tools — directly in your browser. Drag notes on a professional piano roll , quantize timing, change velocity , transpose, edit per-track, and export a clean .MID — no software install, no upload, no sign-up. Professional piano roll Drag notes to change pitch and length, click to add new notes, zoom in for surgical precision. Grid snap on or off, your call. Smart quantization Snap loose performance timing to a clean rhythmic grid from 1/4 to 1/32 — fix sloppy takes without re-recording. Velocity & dynamics Edit per-note velocity to humanize a part. Drag velocity bars below the piano roll, or paint a curve for dynamic shaping. Transpose & change tempo Move the whole piece up or down by semitones, or override the BPM. Use it to play in a singer's key or speed-up practice loops. Multi-track editing Solo, mute, hide or change the instrument on any track. Each track gets its own visibility, color and channel control. Standard .MID export Round-trip safely: import .mid or .kar, edit, export a clean Type 0 or Type 1 MIDI that opens in every DAW and notation app. 01 Import your MIDI Drag and drop a .mid or .kar file, or click to browse. The file is parsed instantly in your browser — tracks, tempo and key signature appear on the timeline. Import your MIDI Drag and drop a .mid or .kar file, or click to browse. The file is parsed instantly in your browser — tracks, tempo and key signature appear on the timeline. 02 Edit notes on the piano roll Click empty grid cells to add notes. Drag existing notes to move them in pitch or time. Stretch the right edge to change duration. Edit notes on the piano roll Click empty grid cells to add notes. Drag existing notes to move them in pitch or time. Stretch the right edge to change duration. 03 Refine timing & velocity Select a range of notes and hit Quantize to snap to a grid. Drag the velocity lane to add expression — louder hits, quieter passes. Refine timing & velocity Select a range of notes and hit Quantize to snap to a grid. Drag the velocity lane to add expression — louder hits, quieter passes. 04 Edit per track Solo a part to focus, mute the drums, or hide a track to declutter the view. Swap an instrument when you need a different feel.

Solo a part to focus, mute the drums, or hide a track to declutter the view. Swap an instrument when you need a different feel. 05 Export the .MID Click Export. A standard MIDI file is downloaded locally — no watermarks, no account required. Open it in your DAW and keep working. Export the .MID Click Export. A standard MIDI file is downloaded locally — no watermarks, no account required. Open it in your DAW and keep working. Producers sketching ideas Quick fixes before DAW import You bounced a MIDI from a hardware sequencer and need to clean up timing before dropping it in Ableton. Quantize, transpose, export — 90 seconds. Students & teachers Edit practice files Slow down the BPM, transpose to a friendlier key, mute the right hand to play along with the left. Re-export for the next lesson. Composers in a browser You're on a school computer or a friend's laptop. No Logic, no Ableton, no Cubase. Sketch an idea in the piano roll and email yourself the .mid. Game audio & sample makers Hand-edit MIDI for tools that demand it Sample mappers, soundfont players and game audio middleware often expect specific MIDI structures. Use this to surgically reshape a file. DAWs win for full music production. But for surgical MIDI edits — quantize a passage, transpose a section, fix a velocity curve — a browser editor opens the file faster than your DAW launches. Can I edit MIDI files online for free? How do I change the tempo (BPM) of a MIDI file? Is it compatible with iPad and mobile browsers? Do I need to install software? Preview the edited MIDI with BPM and loop controls before exporting to your DAW. Render the edited .mid into MP3 or WAV with a SoundFont — useful for quick demos. Inspect tempo, time signature, key, instruments and duration of any MIDI file. Privacy & licensing All editing happens locally in your browser using WebAudio and IndexedDB. Your MIDI files stay on your device — we have no way to read them. You are responsible for ensuring you have the right to edit, share or redistribute the files you use.