How to Stamp a PDF Without Adobe Acrobat (Free, Online)

Acrobat can stamp a PDF, but the useful parts — custom stamps, batch placement, flattened output — sit behind an Acrobat Pro subscription, and uploading contracts to random "free PDF stamp" websites is a privacy decision you shouldn't make casually. There's a simpler path: a stamping tool that runs entirely in your browser, so the PDF never leaves your machine.

The 3-minute workflow

The free PDF stamping tool works like this:

1. Open your PDF. It renders locally — nothing uploads.
2. Add your stamp. Upload a transparent PNG of your seal, pick one you made in the seal generator, or send one over from the stamp digitizer with one click.
3. Place it. Drag to position, resize, rotate, and set opacity so the ink looks pressed rather than printed.
4. Choose scope. Stamp just one page, every page in the same corner, or apply a perforation seal (riding seal) — the tool splits the stamp across page edges automatically, the way multi-page contracts are stamped in East Asia.
5. Export. The seal is flattened into the PDF so it can't be casually dragged off in another viewer.

Because the whole pipeline is client-side, it's as private as stamping the file on your own desk.

Why not the common workarounds?

The Word round-trip — convert PDF to Word, insert the image, convert back — mangles layout in any document with tables or forms, and both conversions often happen on someone's server.

Print, stamp, scan produces a legible but degraded document, kills text search, and takes longer than the digital route every single time.

Acrobat's built-in stamp tool works if you already pay for Pro, but custom image stamps are buried in menus, perforation seals across pages aren't supported at all, and annotations that aren't flattened can be deleted by the recipient in one click.

Getting the stamp image right

The stamp itself should be a transparent PNG — a white box around the seal will cover the text underneath and instantly look fake. If you only have a paper stamp, run a scan or photo through the background remover first; if you're starting from scratch, design one in the online seal generator and use the "Use in PDF stamp tool" button. Placement details for Word and other formats are in how to add a seal to a PDF or Word document.

Does a stamped PDF have legal force?

The stamp image makes the document look properly executed; it does not by itself prove who applied it or when. For many internal workflows, quotes, and invoices that's exactly enough. For contracts where enforceability matters, pair the visual stamp with a compliant e-signature service — electronic seal vs. electronic signature explains where the legal line sits, and are image seals legally valid? covers the question in depth.

Quick answers

Can I stamp every page at once? Yes — choose the all-pages mode and the stamp lands in the same spot on each page.

Can I do a cross-page (perforation) seal? Yes, that's a built-in mode: the seal is split into slices across the stack of page edges.

Is there a file size limit? Processing is local, so the practical limit is your browser's memory — typical contracts are nowhere near it.

Do I need an account? No. Open the tool, stamp, download.