OptimFROG is a lossless audio compression program. Its main goal is to reduce at maximum the size of audio files, while permitting bit identical restoration for all input. It is similar with the ZIP compression, but it is highly specialized to compress audio data.

OptimFROG obtains asymptotically the best lossless audio compression ratios. It has Windows, Linux, and Mac versions, fully featured input plug-ins for the Windows Media Player, foobar2000, Winamp2/3/5, dBpowerAMP, XMPlay, QCD, and XMMS audio players (with bitstream error resilience, ID3v1.1 and APEv2 read tagging support, ID3v2 compatible), optimal support for all integer PCM wave formats up to 32 bits and an extensible streamable (error tolerant) compressed format. It is also fast, the default mode encodes CD quality audio data at 12.4x real-time and decodes at 17.4x real-time on AMD Athlon XP 1800+ (the fastest mode encodes at 28.1x real-time and decodes at 24.7x real-time).