so-vits-svc

so-vits-svc (SoftVC VITS Singing Voice Conversion) is an open-source, offline toolkit for training and running singing-voice conversion models. Rather than synthesising speech from text, it transforms an existing vocal recording so it takes on a different singer's timbre while preserving the source pitch, phrasing and intonation. Under the hood it feeds SoftVC-encoded content features directly into a VITS backbone and swaps the standard vocoder for NSF-HiFiGAN, which cleans up the characteristic 'electronic' artifacts of earlier SVC systems. The 4.1-stable branch adds shallow-diffusion post-processing, multiple pluggable content encoders (ContentVec, HuBERT-Soft, Whisper-PPG, WavLM), static and dynamic speaker mixing, a feature-retrieval / clustering module for stronger timbre control, and ONNX export for downstream deployment. The project is aimed at researchers, vocal-synthesis hobbyists, indie producers and VTuber / virtual-character creators who want full control over a locally-trained voice model — dataset curation, preprocessing (f0 extraction, resampling, chunking), training loop, checkpoint management and inference all live on your own machine. There is no hosted service and no one-click UI in the repo itself; the community typically pairs it with third-party WebUI wrappers. Note: the upstream repo was archived on 2023-11-11, so it is feature-frozen — bug fixes and new encoders now come from forks. The maintainers explicitly frame the project as intended for fictional / consented voices only and disclaim liability for misuse.