OPUS file format (.opus)
Best quality per kilobyte, especially for speech.
Last updated
What is an OPUS file?
In short: An OPUS file (.opus) is an audio file in the OPUS format. Opus is the best general purpose audio codec available, and it is free. It can be converted to MP3, WAV or FLAC for free in a web browser with iHateFiles, without uploading it.
Standardised by the IETF in 2012, combining work from Xiph.Org and Skype.
Opus is the best general purpose audio codec available, and it is free. It handles everything from 6 kbps speech to full transparent music, switching approach automatically, with latency low enough for live conversation. Every voice and video call you make almost certainly uses it.
What OPUS is good at
- Better than MP3, AAC and Vorbis at essentially every bitrate
- Latency low enough for real-time conversation
- Free of patents and royalties
Where OPUS falls short
- Older hardware players do not support it
- Apple support arrived late and is still partial in places
- Less recognised by non-technical users
When to use OPUS
Use Opus for voice recordings, podcasts and anything streamed, where its efficiency shows most clearly.
How to open a OPUS file
Every browser, Android, Windows, VLC, and every modern messaging app.
| Windows | VLC or foobar2000. Windows Media Player does not support Opus. |
|---|---|
| macOS | VLC. The Music app will not import it. |
| Linux | Native — Opus is the default voice codec across the open-source stack. |
| Phone | Android plays Opus natively. iOS needs VLC. |
| In a browser | Every modern browser plays Opus, usually inside a WebM or Ogg container. |
The thing that usually goes wrong
Opus at 64 kbps sounds better than MP3 at 128, so the bitrate you are used to is roughly double what you need here.
Questions
What is a OPUS file?
Best quality per kilobyte, especially for speech. Files use the .opus extension.
How do I open a OPUS file?
Most audio software opens OPUS directly. If yours does not, convert it here to something more common. It takes a few seconds and nothing is uploaded.
Can I convert OPUS for free?
Yes. Every conversion here is free and unlimited, because your own device does the work rather than a server we have to pay for.
Is OPUS lossless?
No. OPUS is a lossy format, so saving discards some detail to save space.