An audio conversion app (also known as an audio converter) transcodes one audio file format into another; for example, from FLAC into MP3. It may allow selection of encoding parameters for each of the output file to optimize its quality and size. An audio converter uses at least two sets of audio codecs to decode the source file format and to encode the destination file. Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source code is openly shared so that people are encouraged to voluntarily improve the design of the software. This is in contrast to proprietary software, where the software is under restrictive copyright licensing and the source code is usually hidden from the users.
Audio converters include:
- AIMP
- Audacity
- Brasero
- CDex
- Exact Audio Copy
- EZ CD Audio Converter
- FFmpeg
- FL Studio
- foobar2000
- FormatFactory
- Freemake Audio Converter
- Free Studio
- fre:ac
- iTunes
- k3b
- MediaCoder
- MediaHuman Audio Converter
- MediaMonkey
- SoX
- VLC Media Player
- Winamp
- WMA Convert
- XMedia Recode
 transcodes one audio file format into another; for example, from FLAC into MP3.){kind=link}