Many lossless audio codec comparisons look at only compression ratio and encoding speed. FLAC decoding is the fastest among lossless codecs and its compression is within 3% of even the most complex codecs. Note that the compression ratios of all lossless codecs falls in a quite narrow range; the difference between the very best and very worst is only around 7%, and only 4% for the practical codecs.

feature comparison

The evaluation of lossless codecs typically depends mainly on features other than speed and compression, which is what our first table shows: features like how well it is supported in devices and software, licensing, etc. For more information on this matter, take a look at the comparison at Hydrogenaudio. Additionally, as archiving is one of the main applications for a lossless codec, of chief importance is the ability to use and recover data in the future. FLAC stands out as the most widely supported codec, and the only codec that at once is non-proprietary, is unencumbered by patents, has an open-source reference implementation, has a well documented format and API, and has several other independent implementations.

Codec Source Available? Player Support? Hardware Support? License Cost OS support Last official release*
flac v1.3.0 YES (OSI approved license) YES (see links page) YES (see links page) NONE Linux, Windows, Mac OS X, *BSD, Solaris, OS/2, BeOS, Amiga OS, others 10 Jun 2013
WavPack v4.70.0 YES (OSI approved license) YES (Winamp, XBMC, foobar2000, CorePlayer, lavc1, DS2, more) SOME (with Rockbox firmware, see WavPack website) NONE Linux, Windows, Mac OS X, *BSD, Solaris, others 28 May 2013
Monkey's Audio v4.12 YES (non-OSI license) YES (Winamp, XBMC, MediaJukebox, dBpoweramp, lavc1, DS2) SOME (Cowon, old Philips GoGEAR, QNAP, Synology, with RockBox firmware) NONE Windows 26 Jun 2013
Apple Lossless YES (OSI approved license) YES (iTunes, XBMC, dBpoweramp, foobar2000, lavc1) YES (most iOS-devices, Sonos, Olive One, some RockBox-devices) NONE Windows, Mac OS X ?
Shorten v3.6.1 YES (non-OSI license) YES (Winamp, XBMC, XMMS, lavc1, DS2) SOME (with Rockbox firmware) non-
commercial only
Linux, Windows, Mac OS 9, Mac OS X, *BSD, Solaris, others 19 Mar 2007
The True Audio 3.4.1 YES (OSI approved license) YES (XMMS, Coreplayer, Foobar2000, Winamp, lavc1, DS2) SOME (iconBIT, with RockBox firmware) NONE Windows, Linux 27 Jul 2007
optimFROG 4.910b no YES (Winamp, XMMS foobar2000, DS2) no ? Windows, Linux Windows 12 feb 2011, Other 26 apr 2006
WMA Lossless no YES (lavc1, DS2) SOME (XBox, Zune, few other) ? Windows ?
Real Audio Lossless no FEW (RealPlayer) no ? Windows, Linux, Mac 19 jan 2009
La 0.4 no YES (Winamp, XMMS, foobar2000) no ? Windows, Linux, Mac 8 feb 2004
Tak 2.3.0 no YES (foobar2000, lavc1, DS2) no free for non-commercial use Windows, Linux via Wine 18 Jun 2013
Ogg Squish 0.98 YES (OSI approved license) no (?) no NONE Linux, Windows, other UNIX Discontinued 2003 in favor of FLAC
Bonk 0.5 YES (OSI approved license) FEW (XMMS) no ? Linux, Windows, other UNIX somewhere in 2002 (now recommends FLAC)

*At the time of writing, which is 3 oct 2013
1lavc = libavcodec-based applications
2DS = DirectShow-based application (filter available)

speed comparison

The machine used for running the test has an Intel Core2Duo T9600 with 4GB of RAM and is using Kubuntu 12.10. The tests are run from ramdisk, as the harddisk is a bottleneck in certain cases. For the codecs that only have Windows-support, the binaries are used through WINE. Measured is the so called cpu time used, not the real time used, except for WMA Lossless and Real Audio Lossless which were timed by hand.

The audio corpus currently consists entirely of CD albums. These are 29 CDs whose genres range from rock to pop to metal to classical to world. The following graphs display the results of these tests: the compression ratio as a function of encoding and decoding speed for the currently most used lossless codecs for all their recommended compression modes.

In the graphs below you can see both the compression and decompression performance of all tested codecs by their speed relative to 'playing speed' on the x-axis and their compression relative to WAVE on the y-axis. The connected dots for each codec are its different presets. For more information on the test environment, codecs and settings, please see the exhaustive report here (PDF).

Please keep in mind that the differences considering archieved compression are exaggerated: in fact, the difference between the best and worst compression is a factor 1000 in time, but only about 7% in space used. So, please mind the axes.



The CD's used in this test are listed below, with a very general indication of the kind of music it should represent.

Some other lossless audio codec comparisons can be found here: