Why your files are never uploaded

Every tool on this site is implemented in JavaScript and WebAssembly that runs in your browser. When you select a file, it is read into browser memory with the File API. Processing happens in a web worker on your machine. The result is written back to a download stream. At no point is the file transmitted to a server, and there is no backend to transmit it to: this is a static site with no application server, no database and no file storage.

You do not have to take that on trust. Open your browser developer tools, switch to the Network tab, and process a file. You will see requests for the page, the stylesheet, the scripts and nothing else. There is no request containing your document, and no upload endpoint to send one to.

Compare that with the common alternative. On most free PDF services the free tier is deliberately constrained — two operations per hour, a watermark stamped across the content, mandatory sign-up, files retained for a period, and a subscription upsell to remove the limits. Those constraints only exist because files are being processed on someone else's hardware. Local processing removes both the cost and the incentive.

The trade-off is honest and worth stating. Browser-side processing is bounded by your device memory, so a very large scanned document on an old phone may be slow. Some server-side features cannot be replicated locally at all, notably high-fidelity PDF to Word layout reconstruction and optical character recognition on poor scans. Where that is the case, this site does not pretend otherwise and does not list the feature.