What is a .opus file?
Opus Audio · Audio · Xiph.Org Foundation / IETF · 2012
Opus is a modern, open, royalty-free audio codec that beats MP3 and AAC at low bitrates, which is why voice chat, streaming and the web rely on it. Files usually end in .opus inside an Ogg container.
What is a .opus file used for?
Opus was standardised by the IETF (RFC 6716) to be one codec that does everything, from low-latency voice to high-quality music, all royalty-free.
It is what Discord, WhatsApp and WebRTC use for voice, and YouTube uses for much of its audio, because it sounds better than the alternatives at the low bitrates those uses demand.
An .opus file is Opus audio wrapped in an Ogg container. VLC and most browsers play it directly.
Older hardware and some Apple software may not support Opus natively, in which case converting to MP3 or AAC is the fix.
How to open a .opus file
The .opus format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list.
Windows
- VLC
- foobar2000
macOS
- VLC
- Music (recent macOS)
Linux
- VLC
- mpv
- Rhythmbox
Web
- Most modern browsers
How to convert a .opus file
You can convert a .opus file to MP3, AAC, WAV, OGG using a conversion tool or the export menu of an app that opens it.
.opus file signature (magic bytes)
Programs recognise a .opus file by the bytes at the start of the file, not by its name. These are the signatures for Opus. For a full breakdown, see the Opus file signature page.
| Hex signature | Offset | Note |
|---|---|---|
| 4F 67 67 53 | 0 | 'OggS'; Opus audio is carried inside an Ogg container |
See the full magic-numbers reference for every format.
Frequently asked questions
What is a .opus file?
Opus is a modern, open, royalty-free audio codec that beats MP3 and AAC at low bitrates, which is why voice chat, streaming and the web rely on it. Files usually end in .opus inside an Ogg container.
How do I open an .opus file?
Play it in VLC or drag it into most modern browsers. On a device that does not support Opus, convert it to MP3 or AAC first.
Is Opus better than MP3?
At the same bitrate, yes, especially at low bitrates, where Opus sounds noticeably clearer. MP3 still wins on universal device support, so convert to MP3 if compatibility matters more than size.
Related formats
Sources
Details on this page were checked against authoritative references: