Watermark PDF

Watermark a PDF without uploading a thing

Add one PDF, choose a text or logo watermark, and download the result. Everything happens on your device: the pdf-lib library loads from this site — never a third-party CDN — the first time you add a PDF, reads how many pages it has, and stamps the watermark locally. There is no account, no forced watermark of our own, and no page cap. You can open this page, disconnect from the internet, and it still works.

A text watermark is the classic case — a word like CONFIDENTIAL or DRAFT laid across the page. Pick from a small set of built-in fonts, set the size and color, and choose how strong it shows. An image watermark stamps a PNG or JPEG logo instead, scaled to a share of the page width. Both share the same placement controls, so a company mark and a status stamp behave the same way.

Text or logo, placed the way you want

Position the watermark in the center, in any corner, or tiled in a repeating grid across the whole page. Opacity runs from faint to solid, so the mark reads without hiding the text underneath, and rotation lets you set the familiar diagonal look. You can stamp every page or only a range you type, such as 1-3, 5, 8-10. A live preview line states exactly what you will get — which word or logo, how many pages, the position, the angle, and the opacity — before you build anything. The watermark is drawn on top of each page's existing content, which is the standard, readable-through watermark look.

What is honest about this tool

This version uses the standard built-in PDF fonts, so custom or handwriting typefaces are not available yet. A password-protected PDF cannot be read without its password, so it must be unlocked before it can be watermarked; the tool says so plainly rather than failing quietly. The watermark sits over the page rather than behind it, and the source file's document properties — title, author, and the like — are not carried into the watermarked copy. The full source code is public on GitHub (AGPL-3.0), and the privacy panel in the footer lists everything this page loads.

Questions

How do I watermark a PDF without uploading it?

Add your PDF, set the text or logo and its position, then choose Apply and download. The watermark is drawn in your browser using JavaScript this page loads from its own site. You can verify it: open your browser's DevTools Network tab while applying — no PDF data leaves your device.

How do I add a CONFIDENTIAL stamp to a PDF?

Keep the type on Text, type CONFIDENTIAL (it is the default), and pick a position — Center or Tile with a rotation of about 45 degrees gives the classic diagonal stamp. Set the opacity so the mark shows without hiding the content, then apply.

Can I use my own logo as a watermark?

Yes. Switch the type to Image, choose a PNG or JPEG logo, and set its width as a share of the page. The logo is embedded directly into the PDF; SVG logos are not supported in this version, so export your mark to PNG or JPEG first.

Can I watermark only specific pages?

Yes. Under Apply to, choose Page range and type the pages you want, like 1-3, 5, 8-10. Only those pages are stamped; the rest are copied through untouched.

Are my PDFs uploaded to a server?

No. Nothing is uploaded and no copy is kept. Your PDF and any logo stay in your browser's memory only while the page is open, and the watermarked file is built and downloaded entirely on your device.

Related tools

Merge PDF — combine PDF files in any order. Split PDF — extract pages or cut one PDF into pieces. Image to PDF — combine JPG, PNG, and WebP images into a single PDF. Photo Editor — crop, resize, redact, and batch-edit images.