Convert MP3 to Opus
Free online converter for MP3 files. Low-latency codec with excellent quality at low bitrates. Nothing to install, no watermark, and every file is deleted automatically.
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Upload a MP3 file to convert it to Opus. Up to 3 files at once, 100 MB each.
Free · up to 3 files · 100 MB each · files deleted automatically after 1 hour.
About MP3 and OPUS
MP3 .mp3
The format that made digital music portable. Lossy, thirty years old, and still the safest choice when you have no idea what will play the file.
Good for
- Plays on essentially every device ever made
- Small files at listenable quality
- Patents long expired, so support is everywhere
Trade-offs
- Lossy — detail is gone permanently
- Beaten by AAC and Opus at the same bitrate
- No transparency about what was discarded
audio/mpeg
Opus .opus
The current state of the art in lossy audio, standardised by the IETF. It outperforms MP3 and AAC across the range and is dramatically better at low bitrates.
Good for
- Best quality per byte of any format here
- Excellent for speech as well as music
- Open, royalty-free, and low latency
Trade-offs
- Lossy
- Older devices and some players will not open it
- Less familiar, so people distrust the file extension
audio/opus
MP3 and OPUS side by side
| MP3 | OPUS | |
|---|---|---|
| Compression | Lossy | Lossy |
| Typically used for | Music, podcasts, anything that must simply play | Voice, streaming, bandwidth-limited audio |
What changes when you convert MP3 to OPUS
This is a re-encode, not a repackage
Some tools can move a stream into a different container untouched when the codecs happen to line up. We do not — every job here is decoded and encoded again, so the conversion takes time in proportion to the length of the file and costs a small amount of quality even where a repackage would have been possible. In exchange the output is predictable: it plays everywhere, rather than inheriting whatever the source happened to contain.
What your OPUS will contain
The output is Opus — encoded with Vorbis at 192 kbps by default. Vorbis is royalty-free and holds up slightly better than MP3 at the same bitrate, though Opus has largely superseded it for new work.
Re-encoding costs a little quality
Both formats are lossy, so this decodes MP3 and compresses again as OPUS. That second pass loses a small amount on top of what was already gone. It is barely audible once, and it accumulates if a file is converted repeatedly — so convert from the original rather than from a previous conversion.
Tags may not survive intact
MP3 stores its metadata as ID3, and OPUS uses Vorbis comments. Standard fields such as title, artist and album normally map across. Anything without an equivalent on the other side — unusual custom fields, some ratings and play counts, occasionally embedded artwork — has nowhere to go. Check the tags before deleting the original if your library depends on them.