M4A to OPUS converter
Convert M4A to OPUS in seconds, free and unlimited. No upload, no sign-up, no watermark: your audio never leaves your device. Re-encodes the audio into OPUS.
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Quick answer: To convert M4A to OPUS, add the M4A file to the iHateFiles M4A to OPUS 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 OPUS.
Should you convert M4A to OPUS?
Do this when OPUS plays somewhere M4A does not. It is a second round of lossy compression, so set the bitrate at or above the original.
Both M4A and OPUS are lossy
M4A (AAC) has already discarded some of the sound, and OPUS (Opus) will discard a little more. The OPUS encoder works from the M4A, 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 OPUS will play
OPUS plays on browsers, Android, WhatsApp and Discord, but not many car stereos or older players.
M4A and OPUS side by side
| M4A | OPUS | |
|---|---|---|
| Inside the file | AAC | Opus |
| Compression | Lossy | Lossy |
| Carries sound | Yes | Yes |
| One minute of stereo | 1 to 1.9 MB | 0.25 to 1 MB |
| Plays on | Apple devices, Android, browsers and most modern players | browsers, Android, WhatsApp and Discord, but not many car stereos or older players |
| Here | Read and write | Read and write |
What usually goes wrong
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.
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.
How to convert M4A to OPUS
- Add your M4A file. It is read from your disk and stays there.
- Check the settings. The output format is already set to OPUS.
- Press convert and the OPUS file is saved back to your device.
Questions
How do I convert M4A to OPUS?
Open this page, add your M4A 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 M4A to OPUS 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 OPUS lose quality?
OPUS 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 M4A files at once?
Yes. Add as many as you like and they are converted one after another, then offered as a single ZIP.