OPUS to M4A converter
Convert OPUS to M4A in seconds, free and unlimited. No upload, no sign-up, no watermark: your audio never leaves your device. Re-encodes the audio into M4A.
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Quick answer: To convert OPUS to M4A, add the OPUS file to the iHateFiles OPUS to M4A converter and press Convert. The conversion runs in your browser, so the file is never uploaded, and it is free with no sign-up, watermark or size limit. Re-encodes the audio into M4A.
Should you convert OPUS to M4A?
Do this when M4A plays somewhere OPUS does not. It is a second round of lossy compression, so set the bitrate at or above the original.
Both OPUS and M4A are lossy
OPUS (Opus) has already discarded some of the sound, and M4A (AAC) will discard a little more. The M4A encoder works from the OPUS, not the original recording, so pick a bitrate at or above the source. A lower one saves space and costs quality you cannot get back.
Where the M4A will play
M4A plays on Apple devices, Android, browsers and most modern players.
OPUS and M4A side by side
| OPUS | M4A | |
|---|---|---|
| Inside the file | Opus | AAC |
| Compression | Lossy | Lossy |
| Carries sound | Yes | Yes |
| One minute of stereo | 0.25 to 1 MB | 1 to 1.9 MB |
| Plays on | browsers, Android, WhatsApp and Discord, but not many car stereos or older players | Apple devices, Android, browsers and most modern players |
| Here | Read and write | Read and write |
What usually goes wrong
About the OPUS. Opus at 64 kbps sounds better than MP3 at 128, so the bitrate you are used to is roughly double what you need here.
About the M4A. M4A, M4B, M4R and AAC are largely the same thing with different extensions. Renaming usually works, though it is not something to rely on.
How to convert OPUS to M4A
- Add your OPUS file. It is read from your disk and stays there.
- Check the settings. The output format is already set to M4A.
- Press convert and the M4A file is saved back to your device.
Questions
How do I convert OPUS to M4A?
Open this page, add your OPUS file, and press convert. The file is decoded and re-encoded by your own browser and saved back to your device. Nothing is uploaded.
Is this OPUS to M4A converter free?
Yes, completely. There is no account, no sign-in, no watermark and no daily limit, because there is no server doing the work. Your own device does it.
Are my files uploaded anywhere?
No. There is no upload endpoint. The conversion runs inside this browser tab, so your file never leaves your device. You can open your browser's network panel and watch: nothing carrying your file is sent.
Is there a file size limit?
No fixed limit. Because the work happens on your machine there is no server quota. The only ceiling is your own device's memory, which for video means very large files may be slow.
Will converting to M4A lose quality?
M4A is a lossy format, so some detail is discarded. The quality control on this page decides how much. The default is set high enough that most people cannot see the difference.
Can I convert several OPUS files at once?
Yes. Add as many as you like and they are converted one after another, then offered as a single ZIP.