An OPUS file is an audio file created in the Opus format. Also called Ogg Opus, this audio format is used for Internet streaming. The OPUS file uses both SILK (used by Skype) and CELT (from Xiph.Org) codecs, and supports variable bit rates from 6 kb/s to 510 kb/s.
An OPUS file can be opened with shareware media players such as VLC that support desktop, Android, and iOS versions.