Guide

How to make your own SoundFont (SF2)

If you've recorded an instrument, sampled a synth, or have a folder of one-shot drum hits, you can turn it into a SoundFont that plays in any DAW. Here's how to do it with Polyphone, a free editor, from the samples to a finished SF2 file.

By Aiden Shihadeh, developer of simpleSF2 · Updated 28 October 2026

Quick answer

Free tool	Polyphone, on Windows, Mac and Linux
What you need	WAV samples, ideally one every few notes
The three layers	Samples go into instruments, instruments go into presets
Time for a simple instrument	About half an hour once the samples are ready
Test it in	simpleSF2 in your DAW, or the free online MIDI player

simpleSF2 plays your finished SoundFont in any DAW on Windows, macOS and Linux. Download free

How a SoundFont is built

An SF2 file has three layers, and every editor shows them the same way:

Samples are the raw recordings, each with a root key (the note it was recorded at) and, for sustained sounds, a loop.
Instruments spread samples across the keyboard: this sample from C2 to F2, the next from F#2 to B2, and so on. Envelopes, filters and tuning live here.
Presets are what a player shows you. Each one points at one or more instruments and has a bank and program number.

Step 1: Prepare your samples

Format: WAV, 44.1 or 48 kHz, 16- or 24-bit.
How many: one sample every three to six semitones sounds natural. One sample for the whole keyboard works for drums, chiptune and lo-fi sounds.
Trim them: cut the silence before each note so it plays the moment you press a key.
Name them by note, like piano_C3.wav, so you can see each root key at a glance.
For drums, keep one hit per file.

Step 2: Import the samples into Polyphone

Download Polyphone. It's free and open source.
Create a new SoundFont, then drag your WAV files into the Samples section.
Click each sample and check its root key. Polyphone shows its own estimate of the pitch; correct the root key if it's wrong, and use the pitch correction setting if the sample is slightly sharp or flat.
For sustained sounds (strings, pads, organs), set a loop start and end inside the steady part of the note. Polyphone shows how smooth the loop is, so you can nudge the points until there's no click. Drums and plucks don't need a loop.

Step 3: Build an instrument

Create a new instrument and drag your samples onto it.
Set each sample's key range so the ranges sit next to each other with no gaps. Each sample should cover the notes around its own root key.
For drums, give each hit a single key, following the General MIDI layout if you want it to work with drum MIDI files (kick on MIDI note 36, snare on 38, closed hi-hat on 42).
Set the volume envelope: a short attack, and a release long enough that notes don't cut off abruptly.
For sustained sounds, set sample mode to loop so the note holds while the key is down.

Step 4: Make a preset and save

Create a preset, drag your instrument onto it and give it a clear name.
Set its bank and program number. Bank 0, program 0 is fine for a single instrument; use bank 128 for a drum kit.
Save as .sf2. Polyphone can also export SF3 (smaller, compressed) and SFZ, but SF2 works in the most players. simpleSF2 opens SF2 and SFZ, not SF3.

Step 5: Test it in your DAW

Load the file in a SoundFont player such as simpleSF2 and play up and down the keyboard, softly and hard. Listen for notes that jump in tone between two samples, clicks at loop points, and notes that cut off. Fix them in Polyphone, save, and import the file again.

To hear it play a whole song without opening a DAW, pick your SF2 in the free online MIDI player and drop in any MIDI file. A SoundFont with one preset plays every part on that one sound, which is a quick way to check its range from the bass up to the top notes. The MIDI to WAV converter saves the same thing as an audio file, handy for a demo.

If you plan to share or sell your SoundFont, only use samples you recorded yourself or that have a licence allowing it. The best free SoundFonts guide explains the common licences.

Common questions

Can I make a SoundFont from a VST?

Yes, by sampling it. Record the VST playing single notes every few semitones, save each one as a WAV, and build the SoundFont from those. Some samplers can automate the recording, but doing it by hand works fine for one instrument.

SF2 or SFZ?

SF2 is one tidy file that almost every player opens. SFZ is a text file plus a folder of samples, easier to edit by hand. See SF2 vs SFZ.

Is there a SoundFont maker online?

There are some, but a desktop editor like Polyphone gives you far more control over loops, key ranges and envelopes, and it's free.