Convert M4A to Opus
Free M4A to Opus converter that runs entirely in your browser. No uploads, no signup required.
Drop M4A files here
or browse your device. Free, no signup required, no watermarks.
Files are processed on your device, never uploaded
Media conversions run on a full FFmpeg engine compiled to WebAssembly. The engine (~31 MB) downloads once on your first conversion, then everything runs locally.
Three steps
How to convert M4A to Opus
Add your files
Drop M4A files into the box above, or click it to browse. Add several to batch convert.
Convert
Opus is already selected as the output. Hit Convert. Your browser does the work locally.
Download
Save each converted Opus file. Pro ZIPs whole batches in one click.
MPEG-4 audio
M4A
M4A is Apple's audio container for AAC, used by iTunes, Voice Memos, and most iPhone recordings.
Opus audio
Opus
Opus is the most efficient audio codec ever standardized, powering WhatsApp voice notes and Discord calls.
Why convert M4A to Opus?
M4A is Apple's audio container for AAC, used by iTunes, Voice Memos, and most iPhone recordings. Opus is the most efficient audio codec ever standardized, powering WhatsApp voice notes and Discord calls. Converting from M4A to Opus gets you the best of the target format wherever M4A falls short, whether that's compatibility, file size, or what your apps and devices can open. With FormatFusion the switch takes seconds and your files stay on your device the whole time.
Questions
M4A to Opus: common questions
Is this M4A to Opus converter free?
Yes. It is completely free with no watermarks and no account required, for files up to 1 GB each. Convert one file or a hundred.
Is it safe to convert M4A files here?
Safer than any upload-based converter. The conversion runs locally in your browser, so your M4A files are never sent over the internet and never touch a server.
Will I lose quality converting M4A to Opus?
Opus is a lossy format, but we encode at high bitrate (up to 192 kbps), which is transparent for normal listening.
Can I convert multiple M4A files at once?
Yes. Free converts up to three M4A files at a time. FormatFusion Pro batches without limits and downloads whole runs as a single ZIP.
Does it work on iPhone and Android?
Yes. FormatFusion runs in any modern mobile or desktop browser. No app install needed.