Free online MID to MIDI converter

A notation program, sequencer, or hardware device may require the .midi extension even when your file is named .mid. Because both extensions normally identify the same Standard MIDI File, the usual solution is renaming the file rather than converting its musical data.

What the .mid format is

.mid is a filename extension for a Standard MIDI File (SMF). The file stores performance events such as note numbers, timing, velocity, controller changes, program changes, tempo, tracks, and metadata; it does not contain recorded audio.

Sequencers, digital audio workstations, notation software, karaoke programs, video-game tools, electronic keyboards, and arranger devices use Standard MIDI Files. Older music libraries and files exported from instruments commonly use the shorter .mid extension.

What the .midi format is

MIDI is a musical communication protocol as well as the name used for related file standards. A file named .midi is normally the same Standard MIDI File as one named .mid; the difference is usually only the filename extension.

MIDI files are small because they contain instructions rather than sound. Their events can be edited to change notes, tempo, transposition, tracks, controller data, and instrument assignments. Playback depends on the synthesizer, sound module, virtual instrument, or operating-system sound set used by the destination, so identical MIDI data can produce different audio on different systems.

How to convert .mid to .midi

Rename the extension

1. Keep a backup of the original file.
2. Show filename extensions in the file manager so the existing .mid suffix is visible.
3. Rename song.mid to song.midi. Do not create a double extension such as song.midi.mid.
4. Open the renamed file in the target program or transfer it to the device.

In Windows File Explorer, use View → Show → File name extensions. In macOS Finder, select the file, choose File → Get Info, and edit the value in Name & Extension. Most Linux file managers allow direct renaming; the terminal command is:

mv song.mid song.midi

Renaming changes only the name, not the file contents. It is appropriate when the file is already a valid Standard MIDI File and the receiving software rejects the shorter extension. You can also convert the file for free on 101convert.com without installing software: upload the .mid file, choose MIDI if an output selection is shown, run the conversion, and download the resulting file.

Re-save with MIDI software

Use a MIDI-capable editor or sequencer if renaming fails, the file may be damaged, or you need to change its Standard MIDI File structure. Open the file, then use a command such as File → Export → MIDI or File → Save As, select Standard MIDI File, and save with the .midi extension. MuseScore, REAPER, Cubase, Logic Pro, and similar applications can import and re-save MIDI files, although menu names differ.

Compatibility and quality limits

Changing .mid to .midi does not change notes, tempo, tracks, timing, or instrument assignments. It cannot repair a corrupt file, convert audio, or make a proprietary non-SMF file into a valid MIDI file.

Standard MIDI Files use format 0, 1, or 2. Format 0 stores all events in one track; format 1 stores synchronized parts in multiple tracks; format 2 stores independent patterns and is less widely supported. If a keyboard or application supports only one SMF type, re-export the file using its required format.

Re-saving can alter metadata, track ordering, event details, or unsupported proprietary chunks. Preserve the original when exact byte-level or event-level retention matters, and verify the result by opening it in the destination software or device.