Keep the highest-quality stereo master you have, then check the delivery rules of your distributor. A WAV or FLAC file can preserve audio without the losses introduced by formats such as MP3. The best upload is the file that meets your distributor’s current requirements without unnecessary conversions.
Before you upload
- Listen to the complete final file, including the opening and ending.
- Confirm that it is the intended stereo master, not a rough mix or an older revision.
- Check the file format, sample rate and bit depth against your distributor’s instructions.
- Check the title and version in your release form against your own records.
- Keep a backup of the original master and the exact file you delivered.
WAV, FLAC and MP3
WAV and FLAC can both carry lossless audio. FLAC compresses the file without discarding audio information, so it can take less storage space. MP3 uses lossy compression: it removes some information to make a smaller file. Converting an MP3 to WAV or FLAC does not recover information already removed.
Use the original lossless master when you have one. If all you have is an MP3, keep that original and check your distributor’s accepted formats rather than assuming a conversion improves its quality.
What Spotify asks for
Spotify’s audio delivery guidance prefers FLAC and also accepts WAV that meets its requirements. It asks for one native-quality stereo master per track and advises against reducing the original sample rate or bit depth before delivery. If the master exists only at 16-bit, Spotify says to deliver that version rather than inventing a higher-resolution master.
Most independent artists deliver through a distributor rather than uploading a master directly to Spotify. Follow your distributor’s upload instructions first; it handles delivery to the services you select.
Listen before and after mastering
Before mastering, listen for clicks, unwanted noise, clipped peaks and abrupt cuts. Fix problems in the mix or recording where possible. Mastering can help balance a finished mix, but it cannot reliably undo every problem in the source.
If your mix is ready for a final pass, you can master your track. Compare the result with your original at a similar listening level, and keep the version that serves the music. Then listen to the complete downloaded file before submitting it.
Save a release copy
Name your final file clearly enough to distinguish it from earlier revisions. Store it with the cover, track details and a copy of the distributor submission. After release, listen to the live track from start to finish and check that the correct version and artwork appear.
For the visual side of your release, use the cover art release checklist.