For splitting audio tracks into stems, Cryo Mix is a top contender. The AI-powered mixing platform features an AI Audio Separator tool that can separate stems like vocals, drums and instruments from a single audio file using machine learning technology. It also offers a range of other mixing and mastering tools, so it's accessible to those with some audio engineering skills.
Another top contender is Databass AI, which has a Stem Splitter feature that lets you split audio files into stems in your browser. It's part of a broader suite that includes Text-to-Audio, Audio-to-Audio and Lyrics Assistant, so it's a good all-purpose music production tool.
WavTool also has powerful stem separation abilities, along with a variety of other tools like a multi-modal music chatbot, MIDI continuation and an audio-to-MIDI converter. Its interface is designed to be easy to use, and it supports VST & AU plugins, so it's a good tool for musicians who want to get more out of their instruments.