Vocal Separator is an online audio tool for recordings you own or have permission to process. It splits a song into vocals and instrumental WAV files, and has a four-stem splitter for vocals, drums, bass and other. Inputs are MP3, WAV, FLAC, M4A and OGG, and it works in modern desktop and mobile browsers. The page says it does not accept YouTube, Spotify or other streaming links.
Free use needs no account, email or payment, with files up to 10 minutes and 100 MB and up to 2 jobs per browser per UTC day, shared with the stem splitter. Downloads expire 55 minutes after processing and uploads are auto-deleted. An experimental no-upload local separator is available on desktop (5 minutes, 50 MB), and a pricing page covers paid plans.
Vocal Separator is a free tool for splitting vocals from the music you own or are allowed to work with.