High-quality MP3, WAV, M4A (Apple Lossless Format), FLAC (Free Lossless Audio Codec), OGG, MKA, AAC, AIFF, and WMA are supported for audio, and MP4, M4V, and MKV is supported for video. The mentioned file formats are supported because they have a separate metadata compartment in which we can embed the ISRC. Imagine it like a suitcase with two different compartments: One for your clean clothes, one for your shoes to keep those two items apart. The metadata compartment is separate from the music/video content. We never touch your music/video. Our work is solely in the metadata compartment.
Please note that it is possible to embed ISRCs, artist, title and other data into WAV & OGG files. HOWEVER, the embedded cover art is NOT reliably displayed by all software/hardware players as of yet. (Recently, MAC computers have added this capability and some players (like VLC player on PC) will now display covers embedded in a WAV & OGG.) Therefore, for those clients who value displaying their cover art while playing the file, we recommend adding another file format that does reliably show the cover (like MP3, M4A, FLAC, etc.).
Many in the music industry still ask for WAV files before considering any other format due to a misconception that MP3 files are inferior to WAV quality. This is NOT true any longer. The MP3 format accommodates various levels of quality, called bit rate. If you set this rate too low then you will receive a small file size with low quality audio. However, MP3 files now accommodate bit rates as high as 320, which results in a top quality recording. (In fact, some say that any quality level of 128 or better is sufficient.)
If you are still concerned about the quality of MP3 then feel free to submit your music in the M4A (Apple Lossless) or the FLAC (Free Lossless Audio Codec) or, if universal cover art display does not matter to you, in WAV or OGG format.
If you need help converting (transcoding) your music from one file format to another, please see our instructions on how to convert WAV to MP3 or M4A using iTunes for free or use this convenient (free) online conversion site.
For free WAV to FLAC file format conversion instructions please click here or try this site, since iTunes does not offer this format.