Inspect before you import
MIDI file checker
Open a .mid file and read its format, tracks, channels, programs, controllers, tempo points, duration, and structural warnings before you send it to a DAW.
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 the checker looks for
The checker reads the parsed event timeline rather than trusting the filename. It reports the SMF type, PPQ, track count, event count, channels, programs, controller types, tempo points, time signatures, and the latest event tick.
Structural checks catch invalid channel numbers, note or velocity values outside the MIDI range, and tracks that do not contain exactly one End of Track event. Errors would block a valid export; warnings are worth checking before the file leaves the browser.
Why a file can open but still import badly
A DAW may accept a file and still map a program to a different instrument, ignore a controller, or interpret a tempo map differently from the source. MIDI carries instructions, not sound. The checker can verify the instructions are structurally readable; it cannot verify that your destination synth agrees with them.
That is why the report includes the actual channels and programs. A track on channel 10 is percussion by General MIDI convention, while the same note on channel 1 is a pitched note. A missing program change can leave the destination on whatever patch it used last.
Use the report before sharing a file
Run the checker before sending a MIDI to a collaborator, uploading it to a marketplace, or importing it into a new DAW. If an error appears, open the full editor and fix the event; if only a warning appears, audition the track in the destination first.
Download the JSON report when you need a record of what was inspected. The report contains the structural summary, duration, key estimate, and compatibility issues, but no audio and no uploaded copy of the file.
Honest limits of a structural check
This is not a virus scanner, a copyright check, or a guarantee that every plugin will reproduce the intended sound. It also does not repair a file automatically. It gives you a clear map of the structure and the specific issues that are visible in the event data.
Files up to 5 MB, 64 tracks, and 20,000 events are supported. Type 2 sequences and SMPTE time division are rejected with an explanation because the editor cannot safely represent them as one PPQ timeline.
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 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