Turn a MIDI file into a real audio recording. Pick a General MIDI instrument kit or load your own .sf2 SoundFont (played by FluidSynth compiled to WebAssembly), choose 44.1 or 48 kHz and 16-bit, 24-bit or 32-bit float, add reverb and download an uncompressed WAV.
Last updated:
No SoundFont chosen yet. Any General MIDI .sf2 file works, for example GeneralUser GS, FluidR3 GM or Timbres of Heaven. It stays on your device.
Parts
Change an instrument or mute a part before rendering.
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How to use the MIDI to WAV Converter
Drop a .mid file on the box, or keep the Ode to Joy demo to try it out.
Choose a SoundFont: one of the General MIDI kits, the built-in synthesizer, or your own .sf2 file.
Set the WAV format: 44.1 kHz for music and CDs, 48 kHz for video; 16-bit, 24-bit or 32-bit float.
Adjust reverb and parts, then press Convert to WAV.
Listen to the result and press Download WAV.
Choosing a sound source
Option
How it plays
Drums
Good for
FluidR3 GM
Recorded samples for each General MIDI instrument, downloaded per instrument
Built-in drum synth
Balanced, realistic all-round results
MusyngKite
Larger, more detailed sample set
Built-in drum synth
Orchestral and piano pieces
FatBoy
Bright, punchy samples
Built-in drum synth
Pop, rock and game music
Your own .sf2 (FluidSynth)
FluidSynth plays the whole file with your SoundFont, including controllers and effects
From the SoundFont
The most faithful rendering, any sound you like
Built-in synthesizer
Simple oscillators shaped per instrument family
Built-in drum synth
Offline use, quick sketches
WAV size per minute (stereo)
Format
44.1 kHz
48 kHz
16-bit PCM
10.6 MB
11.5 MB
24-bit PCM
15.9 MB
17.3 MB
32-bit float
21.2 MB
23.0 MB
The size follows sample rate × channels × bytes per sample × 60: 44,100 × 2 × 2 × 60 = 10,584,000 bytes for one minute of 16-bit stereo.
Tips for better renders
If a part sounds wrong, the MIDI file may use a different instrument than you expect: change it in the Parts list (sample kits) or try another SoundFont.
Keep reverb around 20–35% for a natural room; set it to 0 if you will add your own effects in an editor.
Normalization raises the loudest peak to −1 dBFS so quiet MIDI files come out at a useful level without clipping.
Type 1 MIDI files with many tracks render faster when unused parts are muted.
Frequently asked questions
Why does a MIDI file need to be rendered?
A MIDI file contains no sound, only instructions such as which note to play, when, how hard and with which instrument. To get audio, a synthesizer must play those instructions using instrument sounds. This page does that in your browser and records the result as a WAV file.
What is a SoundFont?
A SoundFont (.sf2) is a bank of recorded instrument samples plus rules for how to play them at every pitch and velocity. General MIDI SoundFonts contain all 128 standard instruments and a drum kit, so any MIDI file sounds roughly as the composer intended. Different SoundFonts can make the same MIDI file sound very different.
Can I use my own SoundFont?
Yes. Choose 'Your own SoundFont file (.sf2)' and pick the file from your device. It is loaded into FluidSynth, a widely used open-source software synthesizer compiled to WebAssembly, which plays the MIDI file exactly as written, including its own drum kit and effects. The SoundFont is not uploaded.
Should I choose 44.1 kHz or 48 kHz?
Use 44.1 kHz for music, CDs and most streaming services, and 48 kHz when the audio goes into a video project, because video editors and broadcast use 48 kHz. Both cover the full range of human hearing.
Which bit depth should I pick?
16-bit is enough for listening and is what CDs use; this tool adds TPDF dither when writing it. Choose 24-bit or 32-bit float if you will mix, master or process the audio further, because they keep more headroom and a lower noise floor.
Why is a WAV file so large?
WAV stores uncompressed audio. A stereo 16-bit file at 44.1 kHz uses about 10 MB per minute, 24-bit about 16 MB per minute. If you need a smaller file, use the MIDI to MP3 converter instead.
Are my files uploaded?
No. The MIDI file is read and rendered in your browser. Only the instrument samples for the sample kits (or the FluidSynth engine) are downloaded from a public CDN; your files and SoundFonts stay on your device.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.