Audio Format
What Is Opus?
Opus is a modern, royalty-free lossy audio codec standardised by the IETF in 2012. It handles both voice and music efficiently across a wide bitrate range — from 6 kbps for voice up to 510 kbps for high-quality music. It is the audio codec behind Discord, WhatsApp voice messages, and most WebRTC applications including Zoom and Google Meet.
Key facts
- Type
- Lossy compressed (royalty-free)
- File extensions
- .opus, .ogg
- Standardised by
- IETF (RFC 6716, 2012)
- Typical bitrates
- 32 / 64 / 96 / 128 kbps
- Bitrate range
- 6 – 510 kbps
- Output support
- MP3, WAV, M4A, AAC, OGG
How Opus works
Opus combines two underlying encoding technologies: SILK (optimised for voice, derived from the codec Skype developed) and CELT (optimised for music, based on work from the Xiph.Org Foundation). The encoder automatically switches between them — and blends them as needed — based on the content and bitrate.
The result is a single codec that outperforms voice-specialised codecs at voice bitrates and competes with AAC for music at higher bitrates. A 24 kbps Opus stream handles voice well and manages music adequately; at 96–128 kbps Opus matches or exceeds AAC at 192 kbps for music quality.
Where Opus is used
- Discord:All voice channels and video calls. Voice quality at 64 kbps is notably better than older VoIP codecs at the same bitrate.
- WhatsApp & Telegram:Voice messages and calls are Opus inside an OGG container — the .ogg files WhatsApp sends are Opus streams.
- Zoom, Google Meet, Microsoft Teams:WebRTC-based video conferencing uses Opus for audio transmission.
- YouTube:Opus is one of the default audio codecs used for video delivery.
- Browsers:Supported in Chrome, Firefox, Edge, and Safari (on recent versions).
Strengths and weaknesses
Strengths
- Best-in-class quality at low bitrates
- Royalty-free and fully open
- Low latency — ideal for real-time audio
- Single codec handles both voice and music
- Native browser support (WebRTC standard)
Weaknesses
- Not supported on most legacy hardware
- iOS only added support in iOS 17 (2023)
- Many DAWs still prefer WAV or AIFF
- Older car stereos and MP3 players cannot play it
When to convert from Opus
- To MP3 — if you need to play a WhatsApp voice message or Discord recording on a device that does not support Opus (older car stereo, legacy MP3 player, some Bluetooth devices).
- To WAV — if you need to import a voice message or podcast recording into an audio editor that does not accept Opus input.
- To M4A — if you want good quality in a container Apple devices handle natively without third-party apps.
Frequently asked questions
Is Opus better than MP3?
At any bitrate below 128 kbps, Opus sounds measurably better than MP3 — often dramatically so at low bitrates. At 96 kbps, Opus is comparable to MP3 at 192 kbps. MP3 only has one advantage: older hardware support.
Why can’t I play .opus files on my iPhone?
iOS added native Opus support in iOS 17 (2023). On older versions, Opus files need a third-party player like VLC. For maximum compatibility with any Apple device, convert Opus to M4A or MP3.
Are WhatsApp voice messages Opus files?
Yes. WhatsApp sends voice messages as .ogg files that contain Opus-encoded audio. If you need to convert them for a device that does not support Opus, convert the .ogg file — the tool treats it as an Opus-in-OGG stream.
What is the difference between .opus and .ogg?
.opus is a file with a raw Opus stream. .ogg is an OGG container that can hold Opus or Vorbis audio. For practical purposes, both can contain Opus audio; most platforms handle them identically.
Should I convert Opus to MP3 for distribution?
Only if you need compatibility with older hardware (car stereos, legacy MP3 players). For any modern device — phones, laptops, smart speakers — Opus plays natively and sounds better at the same file size. Converting to MP3 discards quality.
Convert Opus
Last updated: April 21, 2026