Why the files stay on your machine
Most file-conversion sites work by uploading your document to a server, running a command-line tool on it, and mailing you a link. That means your contract, your passport scan and your unreleased deck all sat on someone else's disk — usually with a promise to delete them in an hour.
Browsers no longer need that. Everything here runs as compiled code inside your own tab: the file is read from disk, processed in memory, and handed back. Any tool that genuinely needs a server will be labelled before you choose a file — none of the current tools do.
No account. No upload. No catch.
Bookmark the tool you use most — it opens straight into the drop zone.