M4A to WAV
Nothing is uploaded. The conversion runs here, on this device.
All conversions
What this does
M4A is an MP4 container carrying audio and nothing else — an iPhone voice memo, an iTunes purchase, an Apple Lossless rip. WAV is its opposite in every way: no container cleverness, no compression, just samples written out one after another. This is the conversion editors, DAWs and DJ software ask for when they refuse the M4A outright.
M4A is what an iPhone voice memo and most iTunes audio are saved as. Software that will not read it almost always wants uncompressed audio instead.
Whether anything is recovered depends on what is inside
An M4A holds either AAC, which is lossy, or ALAC, which is Apple’s lossless codec — the same extension for two different things. That distinction decides what this conversion is worth. From ALAC, the WAV is bit for bit the audio that was there before Apple compressed it, and nothing at all has been lost. From AAC, the WAV is uncompressed but not restored: it contains exactly what the AAC contained, at roughly ten times the size. Either way the result is what an editor wants, because further processing no longer stacks compression on compression. You do not have to work out which one you have; the converter reads both.
Nothing is uploaded
The conversion happens inside this page. Your file is read by the browser, converted here, and saved straight back to your downloads. It is never sent to a server, so there is no upload wait and no size cap beyond what your own device can hold.
Open your browser’s developer tools, switch to the network panel, and convert a file. You will see the converter itself download once, and no upload of your audio at all. That is the whole difference between this and a site that converts on a server, and what that difference actually means is worth a read.
The first conversion is slower
The converter is about 32 MB and downloads the first time you use it, which is the one moment this page is not instant. After that it is cached, and later conversions start immediately, even offline. So do later visits.
Questions
Does converting to WAV improve the quality?
Only if the M4A held ALAC. Then the WAV is a bit-perfect copy of the original and genuinely loses nothing. If it held AAC — the usual case for an iTunes download or a voice memo — nothing the AAC discarded comes back, and no converter can bring it back.
How can I tell whether my M4A is AAC or ALAC?
By size. For the same length, an ALAC file is roughly half of what the WAV will be; an AAC file is nearer a tenth of it. A three-minute track around 15 MB is ALAC; the same track at 3 MB is AAC.
Will the track name and artist survive?
Mostly not. WAV was designed to carry samples and very little else, so the tags an M4A stores — title, artist, album, artwork — have nowhere to go in it. Keep the M4A if you need the metadata; the WAV is the working copy.