Skip to content
All audio conversions

MP3 to OPUS converter

Convert MP3 to OPUS in your browser. No upload and no account: the file never leaves your device, so the only size limit is your device’s memory.

I want OPUS
Advanced 4
sec

Leave both at 0 for the whole file.

sec
Channels

Bytes of your files sent anywhere: 0 B

Related conversions

Need it the other way round? Convert OPUS to MP3

Other ways to convert MP3

Convert other formats to OPUS

Read more about the MP3 format and the OPUS format, or see every audio tool and all audio conversions.

Should you convert MP3 to OPUS?

You want the smallest possible voice or podcast files for chat apps or low-bandwidth streaming.

Fine when a player or app needs OPUS. Converting between two lossy formats compresses the sound a second time, so match or exceed the original bitrate to keep the loss inaudible.

MP3 is the most compatible lossy audio format ever made; OPUS is the most efficient audio codec in common use, especially for speech. Use Opus for speech and streaming where small size matters more than compatibility.

MP3 and OPUS compared
Property MP3 OPUS
Compression Lossy Lossy
Typical quality 128–320 kbps 24–128 kbps
Support Opens everywhere Has patchy support
Best for Music and voice that has to play on anything Voice notes, calls and streaming at low bitrates
Introduced 1993 2012

How to convert MP3 to OPUS

  1. 01

    Add your MP3

    Drop your MP3 file onto the box, or click to choose it. It is read from your disk and stays there.

  2. 02

    Check the settings

    The output is already set to OPUS. Change the bitrate if you want to; the defaults suit most files.

  3. 03

    Save the OPUS

    Press convert and save the OPUS. Several files come back together as a ZIP.

What changes when MP3 becomes OPUS

Two rounds of compression

Each lossy encode throws away a little more. A MP3 at 128 kbps converted to OPUS at 192 kbps sounds like the original; converted at 96 kbps it can turn swirly and dull.

Opus runs at 48 kHz

Opus always works at 48 kHz internally, so other sample rates are converted. It sounds excellent at low bitrates, especially for voice.

Expect a smaller file

OPUS usually stores the same content in less space than MP3. MP3: About 1 MB a minute at 128 kbps, 2.4 MB at 320 kbps. OPUS: A minute of voice note is often under 200 KB.

This page is put together from our notes on each format, choosing only what is true of MP3 and OPUS, so every pairing states the same facts the same way. How these pages are made.

Why it doesn’t upload

Recordings are often private: interviews, voice notes, unreleased music. Your browser can decode and encode audio itself, so there is no reason to send it anywhere.

How to check for yourself

Worth knowing

  • About the MP3. Converting a low-bitrate MP3 to 320 kbps makes it bigger without making it sound any better; what was thrown away is gone.
  • About the OPUS. WhatsApp voice notes exported from a phone are Opus files, sometimes named .ogg, which many players and transcription services refuse.
  • MP3, WAV, M4A, OGG, Opus and FLAC are converted by your browser directly. WMA, AMR, APE, AC3 and the other specialist formats use the FFmpeg engine, a one-time 31 MB download.

Questions

Does converting MP3 to OPUS lose quality?

OPUS is lossy, so a little is discarded, but at the default bitrate the difference is inaudible for nearly everyone.

Will an OPUS play in my car or on my phone?

OPUS has patchy support: browsers, Android and chat apps; many media players, editors and forms can’t open .opus files.

Read more about this

Other tools