What this app does
This tool cleans up MIDI performances by merging near-duplicate notes and removing very short "ghost" notes,
while letting you visually and audibly compare the original and simplified versions side by side.
1. Loading a MIDI file
- Drag and drop a .mid / .midi file onto the drop area, or use the file picker.
2. Simplification settings
- Max gap between notes – notes of the same pitch closer than this gap are merged into a single sustained note.
- Max velocity difference – only notes with similar velocities are merged.
- Min note duration – notes shorter than this are removed instead of kept.
3. Visual comparison
- Original shows the raw MIDI performance.
- Simplified shows the cleaned-up version after processing.
4. Preview-only settings
- BPM – changes the preview speed, not the exported MIDI file.
- Volume, Timbre, Octave – change how the preview sounds only.
- Loop – restarts the preview automatically when it reaches the end.
5. Playing and scrubbing
- Use the Play buttons under each piano roll to audition the original and simplified clips independently.
6. Exporting the cleaned MIDI
- When you are happy with the simplification settings, click Download Cleaned MIDI.
- The exported .mid file contains the simplified version only.
- Preview-only settings never change the exported file.