Opus to MP3

This page converts .opus files to MP3 in your browser: drop the file, choose a bitrate, download. Opus to MP3 is mostly about compatibility, and the audio stays on your device the whole time.

How it works

  1. 1.Drop the .opus files

    Voice notes, call recordings and other .opus files, up to 15 per batch.

  2. 2.Choose a bitrate

    For speech, 128 kbps is more than enough; music sounds better at 192 kbps or above.

  3. 3.Convert

    This Opus to MP3 converter decodes the Opus stream and re-encodes it as MP3 with a WebAssembly build of FFmpeg in your tab.

  4. 4.Download

    Grab the files one at a time or as a ZIP; names stay the same apart from the extension.

Options

  • MP3 bitrate: 128, 192, 256 or 320 kbps, per batch or per file.
  • Start at / Stop at, to cut silence or chatter from the beginning and end of a voice note.
  • Match loudness, so notes recorded on different phones end up at a similar level.
  • Artist, album and year tags for the MP3s.

Why Opus files need converting

Opus is an open, royalty-free codec standardised by the IETF in 2012 as RFC 6716. It was built for both speech and music at low bitrates and with very little delay.

That makes it the codec of real-time audio on the web — WebRTC calls use it — and WhatsApp stores voice notes as .opus files.

Opus always decodes at 48 kHz, so the MP3 you get comes out at 48 kHz too.

Opus packs speech into fewer bytes than MP3, but far fewer players and apps can open a raw .opus file. Converting trades a little size for a format practically everything understands.

Private by design

Voice notes are often personal, so it matters that nothing here is uploaded. The file is read by your browser, decoded and encoded on your device, and the MP3 is handed straight back as a download.

On a computer you can add up to 15 Opus files at once, 200 MB each and 500 MB in total. Phones get 50 MB per file and 120 MB per batch, because a mobile tab has far less memory to work with.

Related converters

OGG to MP3 handles .ogg files, including Telegram voice messages. To keep converted voice notes small, run them through Compress MP3 at 64 kbps, and iPhone recordings in .m4a go through M4A to MP3.