Upload a WMA file and get a M4A back. No signup, no watermark, no limit on how many.
WMA is Microsoft's lossy format from the Windows Media era, and it is the reason a great many CD collections ripped between 2000 and 2010 are now awkward to play.
Where you run into it: Old Windows Media Player rips, corporate archives, CDs backed up on a PC two laptops ago.
What it costs you: Support outside Windows ranges from poor to none: phones, Macs and car stereos mostly will not open it, which is why it is nearly always a source and never a destination.
M4A is an MPEG-4 container holding AAC audio — the same codec as a bare .aac file, wrapped so that players, tags and cover art all behave.
Where you run into it: iTunes and Apple Music purchases, voice memos, Zoom and Teams recordings, most phone-recorded audio.
What it costs you: Outside Apple's ecosystem support is good but not universal, and a few older tools still refuse the extension on sight.
This is a transcode between two lossy formats, so it is a second generation: WMA already discarded detail to get small, and M4A now encodes what is left and discards a little more. On a 320 kbps source you are unlikely to hear it. On something already thin — a voice note, a 96 kbps download — you may. Convert from the best copy you have, never from a copy of a copy.
Yes, entirely, and there is no cap on how many files you convert. No account, no watermark, no trial.
A little, in principle. WMA is already a lossy format and M4A is another one, so the audio is encoded a second time and a small amount more is discarded. From a good source it is very hard to hear; from an already-thin file it can be audible. Always convert from the best copy you have.
Roughly comparable, depending on the quality you pick. At the same bitrate the two files land within a few percent of each other; drop the bitrate and the M4A gets proportionally smaller.
Not here. WMA can be read but not written by this converter — ffmpeg decodes it happily, and encoding back to it would mean a format almost nothing plays. If you need the original WMA, keep it rather than recreating it.
The file is uploaded to do the conversion — nothing here runs in your browser — and both your upload and the converted result are deleted the moment the file is sent back. Nothing is stored and nothing is logged beyond the request itself.