M4A to MP3, without uploading anything

Why you have an M4A at all

Almost nothing sets out to make an M4A. Your phone does. iPhone Voice Memos writes one, Android's recorder often does, WhatsApp exports one, and anything recorded through Apple's stack defaults to it. It is a good format — AAC inside it beats MP3 at the same bitrate — but the world it lands in was built for MP3.

So the reason people arrive here is almost never quality. It is that something refused the file: an old car stereo, a submission form, a transcription service, a DAW, a Windows machine without the right codec, a podcast host that only lists MP3.

What the conversion costs you

Both AAC and MP3 are lossy, so this is a second lossy encode: the MP3 encoder decodes audio that has already been thinned out once and thins it again. At 192 kbps and above, on one pass, almost nobody hears it. It is not free, though, and it stacks if you keep doing it — so convert from the original rather than from a copy of a copy.

The one thing that never helps is asking for more bitrate than the source had. A 128 kbps M4A converted to 320 kbps MP3 is two and a half times the size carrying the same audio, slightly worse. The converter says so when you try it.

The catch nobody mentions: not every M4A is AAC

An .m4a is a container, not a codec. It usually holds AAC, but it can hold Apple Lossless instead, and the extension does not tell you which. The two can differ in size by five times for the same recording.

It matters here because converting Apple Lossless to MP3 is the first lossy step that audio has ever taken, while converting AAC to MP3 is the second. This page reads the codec out of the file and shows it before you commit, so you know which conversation you are having. If it turns out to be Apple Lossless and you want to keep it that way, FLAC is the portable equivalent and this converter writes it.

Tags and album art

Titles, artists, albums, dates and track numbers are carried into the MP3. So is embedded cover art, where the output container can hold it — MP3, M4A, ALAC and FLAC can; a raw .aac stream or a .wav cannot, and there the picture is dropped rather than corrupting the file.

Converting a lot of them

Select as many as you like. They are converted one after another, with the settings you chose applied to all of them, and each result gets its own download link with its original name and the new extension. There is no file-count limit and no daily quota, because nothing is being metered — your own processor is doing the work.

You may not need this page at all

If you have exactly one file and a computer in front of you, there are built-in routes worth knowing. On a Mac, the Music app can make an MP3 version without installing anything. On Windows 11, there is no built-in audio converter, but VLC does it and you may already have it. Both are covered properly in the platform guides: on a Mac, on Windows 11, and without iTunes at all.

This page wins when you have a lot of files, when you are on a machine you cannot install software on, or when you would rather not hand a recording to a stranger's server to get it back thirty seconds later.