Comment by pdfmergely

Author here. Quick note on how the "no upload" claim actually works, since it deserves scrutiny.

There's no upload endpoint to send files to. When you pick a file, the browser hands the app the bytes directly; the work runs in a Web Worker on your device, with WebAssembly for the heavier parts like encryption. The finished PDF is built locally and downloaded. The page is also locked down with a strict CSP so file data has no network path out — you can open the Network tab and confirm nothing leaves while you work. After the first load it works fully offline, which is the easiest proof.

The honest tradeoff: because everything runs on your device, very large files depend on your machine's memory and a phone won't match a desktop. We process a page at a time to keep memory in check.

Tools today: merge, split, reorder, rotate, delete/extract pages, compress, watermark, page numbers, protect/unlock. Free, no sign-up. Would love feedback on what to add next.