Traditional online PDF editors are server applications: your file travels to their data center, gets processed, and travels back. That means your document exists — at least temporarily — on infrastructure you don't control, subject to their retention policies and breach risk.
EditFreePDF works like a desktop app that happens to be delivered through a URL. The editor code (built on the open-source pdf.js, pdf-lib, qpdf and Tesseract engines, compiled to JavaScript and WebAssembly) downloads to your browser once. Your PDF is opened with the browser's file picker and processed in local memory. The “Download” button saves from that memory to your disk. At no point does the document leave your machine — a claim you can verify yourself: open a PDF, switch off Wi-Fi, and every editing tool keeps working.