Turn Opus files into MP3
Drop in an Opus and get an MP3 back. MP3 is the usual choice for music libraries and portable players. Your file never leaves your computer.
Need the other direction? Convert MP3 to Opus
How to convert Opus to MP3
- 1 Drop your Opus .opus file onto the page, or click to browse for it.
- 2 Set the quality, or leave the default, which keeps the file small without anything showing.
- 3 Convert. The work happens on your own machine, so how long it takes depends on your computer and the file.
- 4 Download the MP3, or add more files and do the whole set in one go.
Why convert Opus to MP3
- Plays on every device, browser and stereo ever built.
- All relevant patents have expired, so it is free to use.
- Music libraries and portable players.
- Opus: fewer editing tools handle it directly.
Opus compared with MP3
How the two formats differ on the things that decide whether a conversion is worth making.
| Property | Opus | MP3 |
|---|---|---|
| File extension | .opus | .mp3 |
| Browser support | All current browsers | Every browser |
| Introduced | 2012 | 1993 |
| Developed by | Xiph.Org and IETF | Fraunhofer IIS |
Quality and what changes
Both formats are lossy, so this is a second generation of compression: the Opus is decoded back to pixels that already carry its artefacts, and MP3 then compresses that. The damage compounds rather than cancelling out, which is why repeated round trips visibly degrade an image. Encode at a higher quality than the source used, and convert once from the best copy you have rather than from an already converted file.
- One MP3 limitation to keep in mind: newer formats sound better at the same file size.
Questions about Opus to MP3
Will converting Opus to MP3 lose quality?
A little. Both formats are lossy, so the file is decoded and compressed a second time and the two sets of artefacts add up. At a high quality setting the difference is hard to see, but avoid repeated round trips between lossy formats.
Is my Opus file uploaded anywhere?
No. The whole thing runs inside the browser tab you already have open. Your Opus is read straight from your own disk, converted on your machine and handed back as an MP3. Nothing is sent anywhere, nothing is stored and there is no account.
Is there a file size limit?
There is no server-side limit because no server sees the file. The real ceiling is your device memory, since the input and the output both have to fit in the tab. A few hundred megabytes is usually fine on a desktop machine and considerably less on a phone.
Can I convert several Opus files at once?
Yes. Add as many as you like and they are processed one after another, then offered as separate MP3 downloads or as a single ZIP. Speed depends on your own processor rather than on a queue.
Does the converter work offline?
Yes, after the page has loaded once. The engine is cached by the browser, so you can disconnect, reload and keep converting. That falls out of doing the work locally rather than being a separate mode you switch on.