Convert MIDI to AIFF — Free Online Converter
Convert Standard MIDI File (.midi) to Audio Interchange File Format (.aiff) online for free. Fast, secure audio conversion with no watermarks or regis...
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Upload your .midi file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .aiff file when it's ready.
About MIDI to AIFF Conversion
MIDI (.midi) files serve as the digital equivalent of sheet music for computers — encoding every musical decision (pitch, rhythm, dynamics, instrumentation) as discrete events that any compatible synthesizer can interpret. The .midi extension is the full spelling of the Standard MIDI File format, prevalent on Linux-based music workstations and in academic music computing environments where file extensions are not abbreviated by convention.
AIFF (Audio Interchange File Format) was developed by Apple in 1988 based on Electronic Arts' IFF specification. It stores uncompressed PCM audio in big-endian byte order, making it the native professional audio format on macOS. Converting MIDI to AIFF renders the symbolic score into an uncompressed audio master — the starting point for any professional audio production workflow on Apple hardware.
Why Convert MIDI to AIFF?
Academic music departments and research institutions frequently work with .midi files for computational musicology, algorithmic composition, and music information retrieval research. When these compositions need to be presented, performed, or archived as audio, AIFF provides the uncompressed standard expected by institutional audio archives and Apple-based recording studios.
Film composers who sketch ideas as MIDI before orchestral recording sessions need high-fidelity audio previews for directors and producers. AIFF provides the uncompressed quality that professional review workflows demand, and integrates directly with Logic Pro, Pro Tools on macOS, and Apple's broader professional audio ecosystem.
Common Use Cases
- Rendering algorithmic MIDI compositions to AIFF for academic music research presentations
- Creating uncompressed audio previews from MIDI film score sketches for director review sessions
- Archiving computational musicology MIDI outputs as AIFF for institutional audio repositories
- Preparing MIDI-rendered audio for Logic Pro production sessions requiring AIFF input
- Converting MIDI-based music therapy compositions to AIFF for clinical documentation archives
How It Works
FFmpeg's MIDI decoder extracts tempo, time signature, and key signature meta-events alongside the note and controller data. The synthesis engine processes the event stream chronologically: tempo meta-events set the microseconds-per-beat clock, program change events load instrument patches from the SoundFont bank, and note events trigger sample playback with velocity-to-amplitude curves. The engine sums all active voices across 16 MIDI channels into a stereo PCM bus, which is written to an AIFF container in big-endian format with a FORM/AIFF chunk structure containing COMM (format) and SSND (audio data) chunks.
Quality & Performance
AIFF captures every PCM sample from the synthesizer without modification — bit-for-bit identical to the raw synthesis output. This makes it the ideal format for evaluating SoundFont quality in isolation, without any codec coloring. The synthesis quality depends on the SoundFont's sample content: a SoundFont recorded from Bosendorfer piano at 96 kHz with 127 velocity layers produces near-indistinguishable-from-real results; a basic GM SoundFont with single-velocity 22 kHz samples sounds noticeably artificial. AIFF faithfully exposes both extremes.
Device Compatibility
| Device | MIDI | AIFF |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Partial |
| Linux | Partial | Partial |
| Web Browser | No | No |
Recommended Settings by Platform
Spotify
Resolution: N/A
Bitrate: 320 kbps
OGG Vorbis preferred
Apple Music
Resolution: N/A
Bitrate: 256 kbps
AAC format required
SoundCloud
Resolution: N/A
Bitrate: 128 kbps
Lossless FLAC/WAV for best quality
Podcast
Resolution: N/A
Bitrate: 128 kbps
MP3 mono for spoken word
Tips for Best Results
- 1Render at 48 kHz 24-bit for maximum production flexibility in Logic Pro or Pro Tools on macOS
- 2Use a SoundFont that matches the intended genre — orchestral SoundFonts for film scoring, jazz kits for jazz MIDI compositions
- 3Add the original .midi file as metadata or a companion file alongside the AIFF for future re-rendering with improved SoundFonts
- 4Check the MIDI for orphaned note-on events (missing note-off) before conversion — stuck notes produce continuous tones in the AIFF output
- 5Use AIFF for Apple-ecosystem workflows and WAV when the audio will move to Windows or Linux systems for further processing
MIDI to AIFF delivers uncompressed audio masters from symbolic music data, serving academic, film scoring, and Apple-ecosystem professional workflows where PCM purity is required.