FLAC is a Free Lossless Audio Codec. It can encode audio with a PCM bit resolution up to 32 bits per sample and sampling rates up to 640 kHz. FLAC-encoded audio is usually found either in a native container (which has the extension
.flac), or in an Ogg container (when it's known as OggFLAC).
The format is open and royalty-free. The reference implementation is cross-platform and dual-licensed, command-line utilities (e.g. encoder, decoder and metadata editor) use GNU GPL and code libraries use BSD.
FLAC is suitable for archiving for many reasons:
- open format
- support for metadata tagging
- lossless (no generation loss if you need to convert to another format)
- disk size effective (audio is typically reduced to 50-60% of original size)
- data integrity
- error resistant (bit faults are contained within a frame, typically a fraction of a second)
When FLAC is used as a file format, it begins with the ASCII signature "
In rare cases, this signature may appear following an ID3v2 segment; see ID3#Identification.
Many home stereo and portable hardware music players support the FLAC format. See the FLAC links page for an up-to-date list.
A number of popular audio players support the FLAC format, including:
- Amarok (cross-platform, open source)
- foobar2000 (Windows, non-commercial)
- MediaMonkey (Windows, commercial)
- Songbird (cross-platform, open source)
- VLC (cross-platform, open source)
- Winamp (Windows, commercial)
FLAC is also natively supported by Mozilla's Firefox browser, starting from Firefox 51. For more software products which support FLAC, see the FLAC links page