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What is an Opus file?

Opus gives you the best sound for the size of any common audio format, and handles speech and music equally well. Voice and video calls run on it. Older players will not open one, so MP3 is the safer thing to send. You can convert Opus files here, both into the format and out of it.

Specification

Opus format specifications
Full nameOpus Interactive Audio Codec
Extensions.opus
Media typeaudio/opus
CompressionLossy
Transparency
Animation
Multiple pages
Colour depth
Size limits
Introduced2012
Developed byXiph.Org and IETF
StandardOpen
Browser supportAll current browsers

What Opus is used for

  • Voice and video calls, WebRTC and game chat
  • Podcasts, where speech still sounds excellent in a small file
  • Streaming audio on constrained connections
  • Audio tracks in WebM video

Strengths and limitations

What Opus does well

  • The best sound for the size of any widely supported format
  • Latency as low as 5 ms, suitable for real time
  • Completely royalty free and an IETF standard

Where Opus falls short

  • Car stereos and standalone players mostly will not open it
  • Fewer editing tools handle it directly
  • Detail is still thrown away, so it is not the format to archive in

Convert Opus to

Every target this format can be written out as, each on its own page.

Convert to Opus

Everything that can be turned into a Opus file.

Tools that accept Opus

Questions about Opus

What is a .opus file?

Opus gives you the best sound for the size of any common audio format, and handles speech and music equally well. The extension .opus identifies it, and its media type is audio/opus.

How do I open an Opus file?

Any current browser will open it directly, so dragging the file into a tab is usually enough. Most operating systems also preview it without extra software.

Is Opus lossy or lossless?

Lossy. That means detail is discarded during encoding and each re-save compounds the loss, so keep an untouched master where quality matters.

What is Opus good for?

The best sound for the size of any widely supported format. Latency as low as 5 ms, suitable for real time. Completely royalty free and an IETF standard. In practice that makes it a good fit for voice and video calls, WebRTC and game chat, and Podcasts, where speech still sounds excellent in a small file.

What are the drawbacks of Opus?

Car stereos and standalone players mostly will not open it. Fewer editing tools handle it directly. Detail is still thrown away, so it is not the format to archive in.

Other audio formats

Audio converter or the full format reference