The app
Where splits run
This machine first. A server only when you ask or the machine is slow.
The fast split runs in the browser. Cleaner split on our server, or the Settings override Always on the server, sends the job to the worker instead. A slow computer is sent there automatically.
The worker runs Demucs (htdemucs), an open neural model, and takes about a minute for a song. The parts appear in the mix as one undo step when it finishes. Server splits count against the plan: 2 a month on Free, 150 on the monthly plan.
That is why a split you run today is honest about what it is: parts you can balance, from a filter, on the machine in front of you unless you sent it away. Spend is where a server job would show up.