Convert OPUS files to M4A free in your browser — no signup, no install, and the file is never uploaded to a server. M4A opens almost anywhere, so the result works where OPUS did not.
Add your OPUS file
Drag the OPUS file onto the drop area above, or click it to pick a file from your device. You can add several files at once.
Confirm M4A as the output
M4A is already selected as the output format on this page. You can pick the bitrate — higher keeps more of the sound, lower makes a smaller file.
Run the conversion
Press the convert button. Audio decodes and re-encodes in your browser — a normal song finishes in a few seconds.
Download the M4A file
When it finishes, download the M4A file. Converting multiple files gives you the option to download them together as a ZIP.
A modern codec offering the best efficiency available today for both speech and music. Discord, WhatsApp, and other real-time voice services use it.
An audio file in an MPEG-4 container, usually compressed with AAC. iPhone voice memos and iTunes purchases use this format.
Yes. OPUS to M4A conversion is completely free with no signup, no watermark, and no daily limit on the free plan for ordinary use.
No. The conversion runs entirely inside your browser using WebAssembly, so the OPUS file never leaves your device. That is also why it works without an internet connection once the page has loaded.
The free plan handles files up to 200MB. Because processing happens on your own device, very large files depend on your computer's memory rather than a server quota.
Audio converter
What each file format is, what it is used for, and which formats it can be converted to.
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