Implementations

FLAC playback hard- and software

There is a quite extensive list of hardware vendors selling devices capable of playing back FLAC files at the homepage of the FLAC project.
For a (non-exhaustive) list of playback hardware and software tested against this set of FLAC test files see this page at the Hydrogenaud.io wiki.
For of a list of web browsers capable of playing FLAC files, see caniuse.
As the list of devices and software would grow too large, the rest of this page only deals with decoder libraries, library wrappers, encoders and analysis tools.

Name of library/SDK	Operating system	Remarks
Media Foundation	Windows 10 and later, XBox	Encoding and decoding, details
Core Audio	MacOS 10.15+, iOS 13+, others	Encoding and decoding, details
MediaPlayer MediaCodec MediaExtractor MediaRecorder ExoPlayer	Android	Decoding since 3.1, encoding since 4.1, FLAC-in-MP4 since 10, details
libAudio	SerenityOS	Decoding only, open-source implementation (BSD), details

Name	Programming language	License	Container support	Remarks
libFLAC	C and C++	3-clause BSD	FLAC, OGG	Reference implementation
libavcodec	C	LGPL	FLAC, OGG, MKV, MP4
dr_flac	C	public domain or MIT no attribution	FLAC, OGG	Header-only library
libfoxenflac	C	GPL 2.0	FLAC	Focus on low resource usage, embedded use
flac	Go	Unlicense	FLAC
FLAC-library-Java	Java	GPL 3.0	FLAC
Claxon	Rust	Apache 2.0	FLAC, OGG, MP4	No seeking support
Symphonia	Rust	MPL 2.0	FLAC, OGG, MKV, MP4

Name	Programming language	License	Container support	Remarks	Limitations
libFLAC	C and C++	3-clause BSD	FLAC, OGG	Reference implementation	Produces only fixed blocksize streams Using rice escape code is implemented but disabled
libavcodec	C	LGPL	FLAC, OGG, MKV, MP4	Based on libflake	Produces only fixed blocksize streams Using rice escape code is not implemented Does not mix verbatim, fixed predictor and linear predictor subframes in a stream
libflake	C	LGPL	FLAC	First implementation of variable blocksize encoding, partly merged into libavcodec, development has stalled	At most 24 bits per sample Using rice escape code is not implemented Sample rate limited to 655350Hz Does not mix verbatim, fixed predictor and linear predictor subframes in a stream
FLAC-library-Java	Java	GPL	FLAC		Rather slow
FLACCL	C#	GPL	FLAC	Not a library, uses OpenCL acceleration	Not yet checked

This is a non-exhaustive list of wrappers available for libraries capable of decoding and/or encoding from/to FLAC.

Name	Wraps	Programming language	License	Remarks
libsndfile	libFLAC	C	LGPL
avcpp	libavcodec	C++	LGPL or BSD
flac	libFLAC	Haskell	3-clause BSD
hsndfile	libFLAC	Haskell	LGPL	wraps libFLAC through libsndfile
ExoPlayer	libFLAC	Java (Android)	Apache 2.0
Klipspringer FLAC library	libFLAC	Java	GPL
libflacjs	libFLAC	Javascript/WASM	MIT
libsndfile	libFLAC	Julia	MIT	wraps libFLAC through libsndfile
audioread and audiowrite	libFLAC	MATLAB	N/A
PyAV	libavcodec	Python	3-clause BSD
pyFLAC	libFLAC	Python	Apache 2.0
pysndfile	libFLAC	Python	LGPL	wraps libFLAC through libsndfile
pyminiaudio	dr_flac	Python	MIT	decoding only
libvlc	libFLAC or libavcodec	C++, C#, Swift, Java, Python, Rust, Go	LGPL

Name	Remarks
libfoxenflac	C library capable of running on bare-metal (no runtime necessary)
ESP8266Audio	Library for ESP8266, ESP32 and RP2040 chips
VS1053 and VS1063	FLAC decoder IC. 1053 with software plugin, 1063 without modification

flac, tool usually bundled with libFLAC to encode from and decode to uncompressed file formats like WAV and AIFF. It also has an analysis mode to represent a FLAC file in human-readable form
metaflac, tool usually bundled with libFLAC to view and modify the file-level metadata of FLAC files
fq, tool to help analyse a FLAC file (among other file formats) by representing it in human-readable form
flac.tcl, tool that decodes a FLAC file with a very verbose human-readable analysis of it