This tool bundles libbitsub 1.13.0 (MIT), Tesseract.js 7.0.0 (Apache-2.0), Tesseract.js Core 7.0.0 (Apache-2.0), and the English tessdata_fast model from tesseract-ocr (Apache-2.0).
Sources: https://github.com/altqx/libbitsub ; https://github.com/naptha/tesseract.js ; https://github.com/naptha/tesseract.js-core ; https://github.com/tesseract-ocr/tessdata_fast
All model and runtime files are served from cueconvert.com. Subtitle files remain on the visitor's device.