M4A is the audio format of the Apple ecosystem — the container iTunes, iPhones, and Voice Memos use, built on the modern AAC codec. At the same bitrate it sounds noticeably better than MP3, which makes it a good default for music and podcasts alike. This tool produces a standard M4A from nearly any source, in your browser.
Common reasons to use it: converting old MP3 or WAV files for an Apple-centric library, shrinking large recordings without audible loss, or standardizing mixed-format collections onto one modern codec.
The conversion happens inside your browser via WebAssembly FFmpeg. Your files are never uploaded, logged, or stored anywhere else.
Practically, yes: M4A is an MP4 container holding AAC audio. Apple software prefers the .m4a extension, but the audio inside is standard AAC that most modern players understand.
Yes. Drop in any common video (MP4, MOV, WebM, MKV and more) and its audio track is extracted and converted automatically; the video stream is simply discarded.
No. The conversion is performed by a WebAssembly build of FFmpeg running inside your browser tab. The file never leaves your device, and closing the tab removes it from memory.