Convert MID to FLAC — Free Online Converter
Convert Standard MIDI (.mid) to Free Lossless Audio Codec (.flac) online for free. Fast, secure audio conversion with no watermarks or registration....
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How to Convert
Upload your .mid 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 .flac file when it's ready.
About MID to FLAC Conversion
MID (Standard MIDI File) is a 1983 music notation standard that stores performance instructions — note pitches, velocities, timing, channel and instrument assignments — without any audio content. MIDI files are tiny (10-100 KB) because they describe what to play, not the sound itself. The audible result depends entirely on the synthesizer interpreting these instructions.
FLAC (Free Lossless Audio Codec) compresses audio without discarding any data — every sample is perfectly preserved upon decoding. Converting MID to FLAC renders the MIDI performance using a software synthesizer and SoundFont, then losslessly compresses the resulting PCM audio. This is the ideal format for archiving MIDI renders with zero quality loss and broad cross-platform support.
Why Convert MID to FLAC?
MIDI playback is inherently inconsistent — every synthesizer produces different results. Converting to FLAC captures a specific rendering permanently, with bit-perfect audio preservation. Unlike AAC or MP3, FLAC discards nothing, making it the gold standard for archival and professional use.
FLAC is supported on Windows, macOS, Linux, Android, and most modern audio players. It compresses audio to roughly 50-70% of uncompressed PCM size without any quality penalty. For MIDI renders that may be used as source material for further production, FLAC preserves maximum flexibility while saving storage space.
Common Use Cases
- Archiving MIDI composition renders in lossless format for long-term preservation
- Rendering MIDI arrangements as FLAC source files for mixing and mastering engineers
- Building a lossless sample library from synthesized MIDI instrument patches
- Creating high-fidelity audio previews of MIDI scores for ensemble rehearsal reference
- Storing MIDI soundtrack renders for video production where lossless source audio is required
How It Works
FFmpeg decodes the MIDI file using its built-in SMF parser and routes events to a software synthesizer with a loaded SoundFont. The synthesizer interprets note-on/off events with velocity-scaled amplitude, applies instrument envelopes (ADSR), processes control changes (volume, pan, expression, sustain), and mixes all channels to stereo PCM. This PCM stream is then encoded using the FLAC codec with linear prediction, residual coding, and Rice entropy coding. FLAC compression level (0-12) trades encoding speed for file size with no quality difference.
Quality & Performance
FLAC encoding is mathematically lossless — the decoded PCM is bit-identical to the encoder input. Quality is determined solely by the SoundFont and synthesizer. A premium SoundFont with multi-velocity samples, release triggers, and natural room ambience produces results approaching a real recording. The default GM bank sounds functional but obviously synthetic. FLAC preserves whatever the synthesizer produces, including all nuances and artifacts.
Device Compatibility
| Device | MID | FLAC |
|---|---|---|
| Windows PC | Partial | Partial |
| macOS | Partial | Partial |
| iPhone/iPad | Partial | Partial |
| Android | Partial | Native |
| Linux | Partial | Native |
| 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
- 1Use FLAC compression level 5 (default) for the best balance of encoding speed and file size — higher levels save minimal space
- 2Render at 48 kHz 24-bit for production use or 44.1 kHz 16-bit for distribution
- 3Tag the FLAC file with proper metadata since MIDI titles and track names rarely transfer automatically
- 4Keep the original MIDI alongside the FLAC render — MIDI can be re-rendered with better SoundFonts as they become available
- 5Verify the synthesis output before committing to a batch render by converting a single representative MIDI file first
MID to FLAC combines the universal MIDI instruction format with lossless audio archival. Invest in SoundFont quality for better musical results — FLAC preserves them perfectly.