(Invoking related search suggestions.)
OpenUTAU is a modern, open-source re-imagining of UTAU. It supports many free, high-quality community voicebanks that are compatible with the .UST format.
Yamaha occasionally runs marketing campaigns where buying certain hardware (like the Korg keyboard) or subscribing to a music magazine in Japan includes a code for a free, stripped-down voicebank. Keep an eye on for such events, though they are regional (Japan/Asia often).
: A modern AI-based singing software available for free on Windows and macOS. It includes the default voice library Chis-A and supports VSTi/AU plugins for professional use.
There is no permanently free, full-featured, legal Vocaloid voicebank you can download today.
allows you to create your own voicebanks or download thousands of free ones created by other users, such as Kasane Teto (UTAU version).