Is M4A the same as AAC?

M4A is the container; AAC is the codec inside. We write AAC-LC in an M4A file.

Does this work in Firefox?

Yes — we fall back to a local AAC encoder when the browser lacks WebCodecs AAC.

No. Encoding stays on your device.

128 or 192 kbps is plenty. Use 96 if you need a tiny file.

Turn a WAV into an AAC M4A for Apple devices and voice apps. Runs in your browser. Your file never leaves this device.

Choose a WAV file (any audio file works)
Pick a quality (default High, 192 kbps AAC); set an exact bitrate under Advanced settings
Click Convert and wait for encoding
Preview, then download the M4A