Free online MIDI to MID converter

Some keyboards, sequencers, notation programs, and older websites accept only the .mid extension, so a file named .midi may need to be renamed before it can be opened or uploaded. For a standard MIDI file, this is an extension change rather than a data conversion.

What the MIDI format is

MIDI is event data, not recorded audio. A Standard MIDI File stores note numbers, durations, velocity, tempo, program changes, controller movements, time signatures, lyrics, and track information; it does not contain the sound of a piano, synthesizer, or other instrument.

Digital audio workstations, notation software, composition tools, hardware sequencers, electronic keyboards, and educational applications use MIDI files. Playback depends on the receiving system's synthesizer, soundfont, plug-ins, or connected MIDI hardware, so the same file can sound different on different devices.

Standard MIDI Files commonly use either .mid or .midi. The extension does not identify a different MIDI encoding. The file itself normally begins with a Standard MIDI File header, and its internal format can be Type 0, Type 1, or Type 2. Type 0 stores all events in one track, Type 1 stores synchronized tracks, and Type 2 stores independent sequences; Type 0 and Type 1 are the formats most commonly supported by consumer hardware and software.

What the MID format is

.mid is the shorter filename extension for a Standard MIDI File, not a separate format from .midi. It remains common on older systems and devices that expect a three-letter extension, including some keyboards, sequencers, media players, and web upload forms.

Renaming song.midi to song.mid changes only the filename. It does not change notes, timing, tracks, channels, tempo, controllers, lyrics, MIDI file type, or other file contents.

How to change MIDI to MID

Rename a valid Standard MIDI File when the receiving program only requires the other extension:

1. Make a backup copy of the original file.
2. Show filename extensions in the file manager. In Windows File Explorer, select View → Show → File name extensions.
3. Rename song.midi to song.mid and confirm the extension-change warning.
4. Open the renamed file in the target application or transfer it to the MIDI device.

On macOS or Linux, a terminal command such as mv song.midi song.mid performs the same filename change. In Windows PowerShell, use Rename-Item song.midi song.mid. Make sure extensions are visible; otherwise, a hidden extension can produce a filename such as song.mid.midi.

If the file is not a Standard MIDI File, or the target requires a particular internal structure, open it in MIDI-capable desktop software such as MuseScore, REAPER, or Ableton Live and use its MIDI export command, for example File → Export or File → Save As. Set the output filename to end in .mid. If the software offers a MIDI file type, choose Type 0 for devices that require one track, or Type 1 when separate synchronized tracks must be preserved. Exporting can also be useful when the source is a project file rather than an actual MIDI file.

You can also use the converter on 101convert.com for free without installing software: upload the .midi file, choose MID if a format selector is provided, run the conversion, and download the result.

Quality and compatibility limits

Renaming is lossless because it does not rewrite the file. A real export may merge tracks, change Type 0 or Type 1 structure, omit unsupported metadata or proprietary events, and alter tempo, controller, or lyric data depending on the application.

A file that is rejected after renaming may be an audio file, notation or sequencer project, proprietary device file, corrupted file, or a valid Standard MIDI File whose Type 1 or Type 2 structure the device does not support. Check the target device's documentation before exporting, and do not expect either extension to preserve recorded audio: MIDI contains performance instructions, while audio formats contain sound.