5 free PDF tools that don't upload your files to unknown servers

Most free PDF tools online have the same problem. You upload your document, it goes to a server somewhere, gets processed, and you download the result. You have no idea what happens to your file after that.
For most documents that's fine. For contracts, medical records, tax documents, or anything sensitive — it's a real concern.
Here are five tools worth knowing about, and what actually happens to your files when you use them.

1. FoldPDF Most tools run entirely in your browser. Merge, split, rotate, watermark, sign, protect — your file never leaves your device. Four tools (compress, PDF to Word, PDF to PowerPoint, PowerPoint to PDF) use a secure server but delete files immediately after download. Free, no account needed. foldpdf.online
2. PDF24 Browser-based processing for most tools. Been around for years and has a good reputation for privacy.
3. Stirling PDF Open source, self-hostable. If you want full control, you run it yourself on your own machine.
4. LibreOffice Desktop software. Nothing goes anywhere because it runs locally on your computer.
5. Your browser's print function Underrated. For converting a webpage to PDF, File → Print → Save as PDF works perfectly and involves zero third-party tools.