Vorbis and Opus: two codecs, one container
Vorbis and Opus both come from the Xiph.Org community and can both live in an Ogg container. Vorbis is the older codec from 2000; Opus was standardised by the IETF in 2012 and is more efficient, especially at low bitrates. It is the codec behind WhatsApp voice notes, Discord, video calls in the browser and many web streams.
Check the codec column first. If your .ogg file already contains Opus (Telegram voice messages do), you do not need to re-encode it: renaming the file to .opus is often enough for software that wants that extension.
When converting OGG to Opus makes sense
- Speech and podcasts. Opus at 24–32 kbps sounds clearer than Vorbis at the same rate, so long recordings shrink a lot.
- Web and apps. Opus is supported by all modern browsers and many chat and game engines.
- Saving space. Music at 96–128 kbps Opus often sounds close to 160 kbps Vorbis.
Bitrate guide
| Use | Opus bitrate | Size per minute |
|---|---|---|
| Voice, mono | 24–32 kbps | 0.18–0.24 MB |
| Podcast or audiobook | 48–64 kbps | 0.36–0.48 MB |
| Music, stereo | 96–128 kbps | 0.72–0.96 MB |
Keep in mind that this is a lossy-to-lossy conversion. At very low bitrates, the artefacts of the Vorbis source and the new Opus encode add up. For music, do not go below 96 kbps.
About 48 kHz and tags
Opus files store metadata as Vorbis comments, exactly like OGG Vorbis, so title, artist, album and track number move across unchanged. Your music player will show the same information as before.
Opus always works internally at 48 kHz. A 44.1 kHz Vorbis file is resampled during conversion, which is normal and inaudible. Players report the output as 48 kHz. Older Apple devices, many car stereos and some Windows programs do not play Opus; for those, OGG to MP3 or OGG to M4A is safer. You can also reverse the process later with Opus to OGG.