What this tool changes
Keep every note start in place and change where the notes end. Use a percentage for a uniform articulation change, or let legato extend each note to the next onset.
Articulation control
MIDI note length editor
Keep every note start in place and change where the notes end. Use a percentage for a uniform articulation change, or let legato extend each note to the next onset.
Local file processing
1 Open2 Edit3 Preview4 Undo if needed5 Download
Open a MIDI file
Stay on-device. Start empty if you have no file, or try a public demo.
Off-grid notes, wild velocities, leftover gaps — the dirty AI-song export producers actually get.
A clean four-bar piano phrase you can transpose, quantize, or reshape immediately.
Drums, bass, and chords on separate tracks for mute, solo, and merge practice.
The same hook after quantize and velocity cleanup — the after shot for the messy export.
Your file stays on this device unless you explicitly use Creator Cloud. After an edit, one local recovery copy is saved in this browser until you replace or clear it.
Creator Cloud
Keep the versions and extend the phrase.
Creator Cloud adds cloud history and reviewed AI MIDI edits a month. The tool you are using stays free.
- 60 reviewed AI MIDI edits each month
- 50 cloud projects with 100 versions each
- Cancel anytime; the free editor stays free
What stays in your MIDI
Events outside the selected operation remain in the low-level timeline. Downloading before any edit returns the exact source bytes.
Drop the export into a DAW
- Download the edited file. The name starts with editmidi- so it is easy to spot in a DAW project.
- In FL Studio, Ableton, or Logic, create or open a MIDI track and import that .mid onto the clip or arrangement.
- Audition the destination instrument. MIDI is instructions, so the sound comes from the synth you attach in the DAW.
Three ways to change note length
Percentage mode multiplies each note’s original length by a value from 10 to 400 percent. A value below 100 shortens notes; a value above 100 sustains them longer. Legato mode moves each note end to the next note start in the same track and channel.
Staccato mode halves each note. In every mode, note starts stay fixed and the editor enforces a minimum length of one tick. The last note in a legato pass keeps its original length because there is no following onset to connect to.
Legato is not the same as sustain
Legato here means connecting one note to the next onset in the event timeline. It can create overlaps between different pitches, which is normal for a legato line but may behave differently in a monophonic synth. Check the destination instrument’s voice mode.
Sustain is a controller message, not a note length. EditMIDI does not rewrite sustain here. If the file relies on controller 64, the note lengths can still be changed, but the receiving instrument may hold the sound longer than the visual note length suggests.
Good uses for a length pass
Shorten mechanical piano chords that ring into each other, lengthen a pad so it fills the bar, or make a bass line more staccato without moving its rhythm. The operation is especially useful after quantize when every note has a clean start position.
Work in short loops and compare before and after with the preview. A uniform percentage is fast; legato is more musical for connected lines. Use one undo to restore the complete previous state if the articulation feels wrong.
Drums, limits, and export
Drum channel 10 is excluded by default because changing a drum hit’s length can alter choking or sample behavior. Enable it only when the percussion part is pitched or you intentionally want longer drum events.
The editor keeps every changed end inside the supported tick range and rejects any result that would create a zero-length note. Download MIDI writes a separate file, and the original source remains unchanged on your device.
Keep the same fileAll EditMIDI tools
Open the full index
Every page runs on the same browser MIDI engine, so you can move between them without uploading or re-importing your file.
- MIDI editor online — edit notes, tracks, and velocity in the browser
- MIDI player online — preview tracks, scrub, and loop without uploading
- Transpose MIDI online — change key without losing tempo or controllers
- Change MIDI BPM online — replace a tempo map with one steady value
- Quantize MIDI online — snap note starts and ends to a musical grid
- MIDI velocity editor — set note dynamics from 1 to 127
- MP3 to MIDI converter — turn a melody into an editable piano roll
- Audio to MIDI — sketch one melody from a local recording
- Suno MIDI cleanup — quantize and fix messy AI exports
- MIDI to MP3 — render a MIDI file to WAV or MP3 in this browser
- Piano roll viewer — see every note, pitch, and length in a .mid file
- WAV to MIDI converter — draft notes from an uncompressed recording
- Vocal to MIDI — turn a hummed or sung line into editable notes
- MIDI key finder — estimate the key, relative key, and Camelot code
- Merge MIDI files — combine two .mid files into one multi-track project
- MIDI file checker — inspect structure, channels, tempo, and compatibility risks
- MIDI duration calculator — read seconds, bars, beats, and tempo points
- MIDI to CSV — export one row per note for a spreadsheet
- MIDI to JSON — export a versioned structured note object for apps and AI
- MIDI to video — record a vertical, square, or widescreen piano-roll clip
- MIDI cover art generator — export a 1500px PNG from the note pattern
- Humanize MIDI — add bounded timing and velocity variation with a repeatable seed
- MIDI velocity curve — reshape dynamics with a gamma curve
- MIDI to WAV — render uncompressed 44.1 or 48 kHz audio locally