Under recommendation from a number of DSPs we work with, we do not accept .mp3 files due to the way they are compressed. WAV files ensure lossless compression and allow us to deliver your music to streaming sites and digital stores at the best possible quality.
What are the requirements for my .Wav file?
The file needs to be stereo, 16, 24, or 32 bit between 44.1 and 192 kHz, non floating point WAV file.
If your upload fails, we recommend re-outputting it to those specifications from whichever program you originally used to output your file.
If you don't have access to the original software, you might alternatively be able to use a free tool like this one or this one to convert your current file, but it might make your song sound strange, so please listen to it carefully after you convert it to check the sound quality has not been compromised!