Upload the highest quality version of your audio that you have. If you have a lossless master (WAV, AIFF, or FLAC), use that.
A few guidelines:
- Lossless is best - WAV, AIFF, and FLAC preserve the full quality of your recording and give listeners the option to download in any format
- 24-bit is preferred over 16-bit if you have the choice - it's the standard for high-quality digital audio
- Don't upsample - if your recording was made at 16-bit/44.1kHz, upload at that resolution rather than converting it to a higher bit depth. Upsampling doesn't add quality and can introduce artifacts
- MP3 uploads are supported but we recommend lossless where possible
If you're not sure what format your files are in, check with whoever mixed or mastered your release.