Convert OPUS to M4A

Tested on Windows 11, 24 October 2026

Convert OPUS audio to M4A in your browser or in the Filoshi app for Windows. M4A is lossy: Filoshi uses a high-quality setting, and you can choose the bitrate. Nothing is uploaded.

Get Filoshi · $29Many files at once, no size limit, on Windows.

How to convert OPUS to M4A in your browser

  1. 1
    Drop your OPUS file
    Drag it onto Filoshi above, or press Choose your OPUS file to pick it on your computer.
  2. 2
    Filoshi converts it
    M4A is chosen already. FFmpeg, compiled to WebAssembly, converts it inside this browser tab.
  3. 3
    Save your M4A file
    Download it when it is ready. Nothing was sent to a server.
Source format

What is OPUS?

Opus Audio (.opus). Opus is an open, royalty-free codec standardised by the IETF in 2012. It sounds very good at low bitrates for both speech and music, and it is the codec of WebRTC video calls and many voice-message apps.

Common use: Voice messages, calls, streaming, podcasts

Output format

What is M4A?

MPEG-4 Audio (.m4a). M4A is an MP4 file that holds only audio, normally AAC (sometimes Apple Lossless). It is what iTunes, Apple Music downloads without DRM and iPhone voice memos use.

Common use: Apple Music and iTunes, voice memos, podcasts

Questions about OPUS to M4A

Is converting OPUS to M4A free?
Yes, one file at a time: the converter on this page runs in your browser, files up to 100 MB, no sign-up. The Filoshi desktop app ($29 once, for Windows) converts many files at once and has no size limit.
Does converting OPUS to M4A lose quality?
Yes, a little. M4A is a lossy format, so some detail is thrown away when the file is saved. Filoshi uses a high-quality setting by default, and you can choose the bitrate in the file viewer. OPUS is lossy too, so this is a second round of compression; convert from the original, not from earlier conversions.
Is my OPUS file uploaded anywhere?
No. The converter on this page runs in your browser with FFmpeg compiled to WebAssembly; your OPUS file is read and converted on your device and never sent to a server. The desktop app works the same way, offline.
Has OPUS to M4A been tested?
Yes. OPUS to M4A is one of the 1,841 conversions that passed Filoshi's automated test matrix on Windows 11.
Can I convert many OPUS files at once?
Yes, in the desktop app. Drop as many OPUS files as you like on the window, pick M4A once for all of them, and each file shows its own progress. The new files appear next to the originals, which are never changed.

Related conversions

Other OPUS conversions

OPUS to MP3OPUS to AACOPUS to OGGOPUS to FLACOPUS to AIFFOPUS to AC3OPUS to AUOPUS to CAF

Convert to M4A

MP3 to M4AWAV to M4AAAC to M4AOGG to M4AFLAC to M4AWMA to M4AAIFF to M4AALAC to M4A

Need OPUS to M4A for many files?

The browser converter handles one file at a time. The Filoshi app for Windows converts as many as you drop, runs offline, and has 1,841 tested conversions.

Get Filoshi · $29