How to check a converter's "no upload" claim yourself
Any tool can put "no upload" in its marketing copy. The way to verify it takes about 30 seconds: open your browser's DevTools (F12), switch to the Network tab, clear the log, and then run a conversion. If your file's bytes appear anywhere in an outbound request, it was uploaded — no matter what the page says.
Running that check against PrivaPDF shows exactly two small local requests (the Web Worker script and the WebAssembly binary, both cached after your first visit) and nothing carrying your document's content, because the conversion genuinely happens inside the browser tab rather than on a server somewhere.