Most file tools on the internet work like this: upload, process on a server, download. The moment you upload a contract, a design file, or a video, a copy of it exists on someone else's infrastructure. Data privacy is not a feature add-on — it is a design decision.
Source: [Dev.to](https://dev.to/anyfyle/why-your-files-should-never-leave-your-device-browser-based-file-processing-pn)