Kits AI vs Sinsy

Kits AI provides audio tools for creating and changing voices and working with vocals and music. Its features include voice cloning and conversion, vocal enhancement and removal, stem splitting, AI mastering, harmonies, pitch editing, and key and BPM detection. The voice-changing tools include a library of 100+ royalty-free artists. A Windows desktop app supports drag-and-drop into a DAW or other music production software and simultaneous auditioning of multiple vocal models; Kits AI is also available through a browser and API. The API lists voice conversion, blending, and vocal removal endpoints, while text-to-speech was deprecated from the API as of September 22, 2025. Kits says voices used in its models are licensed and sourced from artists, who benefit through revenue sharing. The free plan includes 15 conversion minutes, no voice slots, and no download minutes. Paid plans start at $10 a month. Submitted and generated audio may be used to improve the services, including related AI and machine learning models.

Sinsy is a free web service that generates singing vocals from musical scores. You upload a MusicXML score, choose a vocal, and adjust settings labeled ALP, VIB, and PIT; Japanese appears as a language option. The system uses DNN- and HMM-based synthesis to model characteristics such as pitch and timbre, rather than accepting vocal input. Sinsy was developed by the Tokuda, Nankaku, and Hashimoto Laboratory. Its version history lists version 5.1 on 2026/05/01, with fixes for parameter-panel and smartphone/tablet behavior. Earlier entries record compressed MusicXML upload support in version 4.4 on 2023/12/25 and the addition of Japanese DNN vocal f01027j_dnn_beta5 in version 4.5 on 2024/12/25. The service is listed for web and Linux. Its Free online synthesis plan costs nothing. The synthesis page says using the service implies agreement to its terms of use. The about page is available in Japanese and describes the research background and version history.