What this tool changes
Open the base MIDI file, then add a second .mid with the toolbar. The incoming tracks join the same project, and both files stay on this device.
Combine two files
Merge MIDI files online
Open the base MIDI file, then add a second .mid with the toolbar. The incoming tracks join the same project, and both files stay on this device.
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.
What merging two MIDI files actually does
The first file is the base. Its PPQ value becomes the shared timing grid. Tracks from the second file are copied into the project and their event ticks are scaled when the two files use different PPQ values. The result is written as a Type 1 file.
Notes, controllers, programs, pitch bend, track names, and tempo events from the incoming file remain in the timeline. A conductor-only track at the start of the second file is skipped when that file has other musical tracks, which avoids stacking a second empty conductor lane.
Choose the base file deliberately
Start with the file whose tempo map and track layout you trust. The merge keeps the base structure and appends incoming tracks; it does not try to reconcile two different arrangements or choose a winner when both files contain tempo changes.
If both files have tempo events, inspect the merged tempo map before export. Most DAWs follow one conductor map, and two competing maps can make the result sound different from either source. Use the tempo tool first when you need one clear BPM.
A practical merge checklist
Open the base, merge the second file, and look at the track list before downloading. Rename tracks so the source is obvious, mute or remove duplicates, and check the piano roll where the two arrangements overlap. Then preview short sections around the join.
The file checker can flag invalid channels, missing End of Track events, and range problems. It cannot know whether the destination synth maps program 40 to the same instrument as the source, so audition the result in the software that will play it.
Track and event limits
Merging is bounded by the same editor limits as every other operation: up to 64 tracks, 20,000 events, and 5 MB per opened file. If the combined project would exceed a limit, the merge stops with a clear error instead of producing a partial file.
The original files are not modified. One Undo restores the project before the merge, and Download MIDI writes a separate file with a name that starts with editmidi-. The merge runs locally, so no MIDI content is uploaded.
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
- 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 note length editor — make notes shorter, legato, or staccato
- MIDI to WAV — render uncompressed 44.1 or 48 kHz audio locally