Most tools on this site (PDF tools, image tools, calculators, QR/barcode/password generators) process everything locally in your browser using JavaScript. Your files are never uploaded or stored on any server.
A few tools (Speed Test, What Is My IP, DNS Lookup) need to talk to the network by nature — they query your public IP and run network measurements using your browser, the same way any diagnostics site does. We don't log or store the results.