Step 1: Supply your MP3 files using the button above or by haul and lay.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Get your converted Opus files.
MP3 to Opus Conversion FAQ
Is the MP3 to OPUS conversion reversible?
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You can convert the OPUS back to MP3 on this site. If either format involved is lossy, the round-trip is not bit-perfect even though it is visually or audibly close.
What output quality should I expect from MP3 to OPUS?
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Default settings target broadcast / web quality — visually identical to the source for most viewers. For archival use, pick the highest quality option in the converter settings.
Is converting MP3 to OPUS a second round of lossy compression?
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Yes, and it is worth planning around. Both formats are lossy, so the OPUS encoder is working from audio that has already been through one psychoacoustic pass, and its own decisions compound the first set. At 192 kbps or above the result is still transparent for most listening. If you have a lossless master anywhere, encoding the OPUS from that instead avoids the double pass entirely. MP3 is lossy: a psychoacoustic model discards frequencies the ear is unlikely to notice, typically at 128 to 320 kbps. Opus scales from 6 kbps mono speech to 510 kbps stereo music in the same bitstream and switches modes automatically.
What exactly is an OPUS file?
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A container with the audio inside it, rather than the audio on its own. That extra layer is where the length, the seek index and whatever metadata the format defines are kept, so a player knows how long an OPUS is before decoding a single frame instead of scanning the whole file to find out. It also means the extension does not always settle what is inside: several containers of this kind are allowed to hold more than one sort of audio, which is why two OPUS files can behave differently while looking identical from outside.
Will the OPUS play in my car or on older hardware?
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Often not. MP3 is decoded by essentially everything, including car head units and elderly players; OPUS needs software that knows the codec, which standalone hardware frequently does not have. If the destination is a car stereo or a portable player, that is a strong argument for staying on MP3. Opus is almost never supported by standalone hardware — assume software playback only, and expect car stereos to ignore it.
Is MP3 free to use and distribute?
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Yes, without conditions worth worrying about. The specification is public, anyone can implement an encoder or decoder without asking or paying, and nobody can change those terms later — which is why it turns up in open-source tooling, in game engines and anywhere a licence negotiation would have killed the project. Converting away from it does not undo that; the files you already have stay exactly as usable as they were.
Is OPUS too new for the things I need to play it on?
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That is the one real risk with it. OPUS is a recent codec and it is genuinely better than the older ones at the same bitrate — noticeably so below 96 kbps — but "better" is not "supported", and a car head unit, a standalone player or a television from before it existed will simply not recognise the file. Browsers, phones and computers are fine. Check the oldest device that has to play it and choose on that, not on the numbers.
Is there a file-size limit when converting MP3 to OPUS?
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Free conversions have a size limit per file, set by the type of file, and the page tells you when a file is over it. A paid plan removes that limit, so much larger files can be converted.
Can I batch-convert several MP3 files to OPUS at once?
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Several files in one job need a paid plan. Free use is one file per conversion, one conversion an hour. On a paid plan you can add several files to one job, then download each result on its own or all of them in one ZIP.
What happens to my MP3 files after the conversion?
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Uploaded files are processed on our own conversion servers, nobody looks at them, and they are not shared. The upload and the converted file are both deleted automatically about 24 hours after the conversion, which leaves time to download the result. See /privacy/ for the full policy.
What apps can play a OPUS file?
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OPUS plays in most music players, browsers, and media libraries. iTunes / Apple Music, VLC, Foobar2000, and phone media apps handle it natively.
Do I need to install software to convert MP3 to OPUS?
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No. The converter runs entirely in your browser plus our cloud — no plugin, no install, no admin rights. It works on Windows, macOS, Linux, ChromeOS, iOS, and Android.
