Whether you are just starting out in the world of digital music by ripping your original CD collection, or want to make sure that you have perfect copies of all your originals in case disaster strikes (like a scratched CD), building up a lossless digital music library is the ultimate way to go.
The list below showcases audio formats that are able to encode audio and compress it in a lossless way ensuring your music is perfectly preserved in digital form.
The FLAC format (short for Free Lossless Audio Codec) is probably the most popular lossless encoding system which is becoming more widely supported on hardware devices such as MP3 players, smartphones, tablets, and home entertainment systems. It is developed by the non-profit Xiph.Org Foundation and is also open source. Music stored in this format is typically reduced between 30 - 50% of its original size.
Common routes to rip audio CDs to FLAC include software media players (like Winamp for Windows) or dedicated utilities -- Max for example is a good one for Mac OS X.
Apple initially developed their ALAC format as a proprietary project, but since 2011 has made it open source. Audio is encoded using a lossless algorithm which is stored in an MP4 container. Incidentally, ALAC files have the same .m4a file extension as AAC, so this naming convention can lead to confusion.
ALAC isn't as popular as FLAC, but could be the ideal choice if your preferred software media player is iTunes and you use Apple hardware such as the iPhone, iPod, iPad, etc.
The Monkey's Audio format isn't as well supported as other competing lossless systems such as FLAC and ALAC, but on average has better compression resulting in smaller file sizes. It isn't an open source project, but is still free to use. Files that are encoded in the Monkey's Audio format have the humorous .ape extension!
Even though most software media players don't have out-of-the-box support for playing files in the Monkey's Audio format, there is a good selection of plug-ins now available for: Windows Media Player, Foobar2000, Winamp, Media Player Classic, and others.
4. WMA Lossless (Windows Media Audio Lossless)
WMA Lossless which is developed by Microsoft is a propriety format that can be used to rip your original music CDs without any loss of audio definition. Depending on various factors, a typical audio CD will be compressed between 206 - 411 MB using a spread of bit rates in the range of 470 - 940 kbps. The resultant file that is produced confusingly has the .WMA extension which is identical to files that are also in the standard (lossy) WMA format.
WMA Lossless is probably the least well supported of the formats in this toplist, but could still be the one you choose especially if you use Windows Media Player and have a hardware device that supports it such as a Windows phone for example.
The WAV format isn't thought of as the ideal choice when choosing a digital audio system for preserving your audio CDs, but still remains a lossless option. However, the files produced will be larger than the other formats in this article because there isn't any compression involved.
That said, if storage space isn't an issue then the WAV format has some clear advantages. It has widespread support with both hardware and software. Much lower CPU processing time is required when converting to other formats because WAV files are already uncompressed -- they don't need to be uncompressed before conversion. You can also directly manipulating WAV files (using audio editing software for instance) without having to wait for a de-compression/re-compression cycle in order to update your changes.