Launching swipemerge — a free PDF merger that runs 100% in the browser

Hey IH 👋

We just shipped swipemerge — a free PDF merger that runs entirely in the browser. No upload, no signup, no email. Drop your PDFs, swipe to reorder, hit download. Done.

Why we built it: every time someone on our team needed to glue two PDFs together, they ended up on a sketchy ad-laden site that wanted an email address before letting them do anything — and uploaded their bank statements to who-knows-where. That's a pretty broken default for a task that should take five seconds.

Key points: 100% client-side via pdf-lib + WebAssembly (files never leave the browser), no accounts or watermarks or page limits or premium tier, free forever.

Stack: Next.js (App Router) on Cloudflare Pages, pdf-lib for the actual merging, a custom swipe-to-reorder UI that took way more iterations than expected to feel natural on both touch and mouse, and Plausible for analytics (no cookies, no PII).

Business model: none. It's a side project from our team at swipesign (we build eIDAS-compliant electronic signatures). swipemerge is purely a give-back — the kind of tool we wished existed when we needed it.

What's next: PDF split (same UX, reverse direction), page reordering inside a single document, and compression — all still client-side.

Looking for feedback on three things. Is the name "swipemerge" memorable or weird? Does the swipe interaction feel right on your device? Anything obviously missing from your PDF workflow we should add?

Link: https://www.swipemerge.com

Happy to answer anything about the implementation, the privacy model, or why we don't monetize.