TTA is an extension specific to files that store digital audio material. The content of TTA files is lossless compressed based on the Free Lossless True Audio (TTA) codec. The data compression ratio in such files can vary from 30% to even 70%. Thanks to lossless compression, after unpacking, the data is identical to the original data without loss of sound quality.

Compression to TTA format is done in real time. Most often, these files are generated based on data from WAV files saved in various bit resolutions.