Windows 10 will support FLAC audio file format out of the box. FLAC (Free Lossless Audio Codec) is an open audio coding format for lossless compression of digital audio. Digital audio compressed by FLAC's algorithm can be reduced to 50–60% of its original size and decompressed to an identical copy of the original audio data. Windows Media Player in Windows 10 will support MKV videos too without any additional codec.