Show HN: PDFMergely – In-browser PDF tools that never upload your files

To me, it looks like a design generated by AI. It had exactly the same vibe as those kinds of sites I see all the time.

Why is it that everyone now duplicates/vibe-codes PDF tool websites? It seems that there is one new each week for about half a year now with none providing any outstanding features over the others.

Which library did you compile to WASM for this? I doubt this is a from scratch implementation of full PDF

Where is the company registered? None of these details are on your website.

Love the idea, but would help trustworthiness if the design looked a little less vibe-coded.

Question about merging: How do you handle merging multiple pdf that have forms? Are the form fields renamed to prevent form field name clashes?

And what pdf toolkit do you use?

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.