SFZ (file format)

SFZ is a plain text file format that stores instrument data for software synthesizers. The SFZ format was developed by René Ceballos (founder of RGC Audio)[1] and is now maintained by Cakewalk. SFZ is a royalty-free format and can be used by software developers for both free and commercial purposes. The SFZ Format is widely accepted as the open standard to define the behavior of a musical instrument from a bare set of sound recordings.

SFZ file format

Filename extension	.sfz
Developed by	Rene Ceballos
Type of format	Markup language

Similar file formats are the proprietary standards of Native Instruments Kontakt .nki, .nkm.

A simple example of an SFZ file:

<group>
lovel=0
hivel=127

<region> trigger=attack  pitch_keycenter=60 lokey=30 hikey=61 sample=SubDir/01C4.wav
<region> trigger=attack  pitch_keycenter=62 lokey=62 hikey=63 sample=SubDir/02D4.wav
<region> trigger=attack  pitch_keycenter=64 lokey=64 hikey=64 sample=SubDir/03E4.wav
<region> trigger=attack  pitch_keycenter=65 lokey=65 hikey=66 sample=SubDir/04F4.wav
<region> trigger=attack  pitch_keycenter=67 lokey=67 hikey=68 sample=SubDir/05G4.wav
<region> trigger=attack  pitch_keycenter=69 lokey=69 hikey=70 sample=SubDir/06A4.wav
<region> trigger=attack  pitch_keycenter=71 lokey=71 hikey=71 sample=SubDir/07B4.wav
<region> trigger=attack  pitch_keycenter=72 lokey=72 hikey=73 sample=SubDir/08C5.wav
<region> trigger=attack  pitch_keycenter=74 lokey=74 hikey=75 sample=SubDir/09D5.wav
<region> trigger=attack  pitch_keycenter=76 lokey=76 hikey=108 sample=SubDir/10E5.wav

The SFZ format isn't maintained by a single company or group, and supported features can vary between individual synthesizers. The official page at the Cakewalk web-site is no longer available, however descriptions of the SFZ opcodes can be found on various websites.

Applications exist that provide a point-and-click GUI for creating SFZ files, as an alternative to editing the text directly.