RAW files (ORF, CR2, NEF, ARW…) are decoded experimentally. Browsers have no built-in RAW codec, so on convert this loads a WebAssembly build of LibRaw once, into this tab, and decodes the file on your device — still nothing uploaded anywhere. It can be slow on large files and won't cover every camera model; if a file fails, it'll say so instead of downloading something broken.
Nothing uploaded yet — your converted files will never touch a server.