Watermark PDF
Add a text watermark to every page of a PDF online for free, diagonal, centred, tiled, or footer layout with custom opacity and colour. No uploads.
About This Tool
Mark a document as a draft, a copy or confidential in seconds. Type your text, pick a layout, and it is stamped onto every page at the opacity you choose. Diagonal and tiled layouts sit behind the eye without hiding the content, while the footer layout keeps a discreet line at the bottom of each page. Everything runs inside your browser, the PDF is never uploaded.
How To Use
- Drop your PDF into the upload zone or click to select it.
- Type the watermark text and choose a layout, size, opacity and colour.
- Click "Add Watermark" and download the stamped PDF.
How It Works
A watermark is drawn as ordinary PDF text content on top of each page. Because it is real text rather than a flattened image, the rest of the page, selectable text, links and vector graphics, stays exactly as it was, and the file grows by only a few hundred bytes.
The diagonal layout measures the page and shrinks the type until the line fits across the diagonal, so short and long phrases both sit neatly inside the page. The tiled layout repeats the text on a grid at a shallow angle, which is much harder to crop out of a screenshot. Opacity is applied through the PDF graphics state, so the text stays crisp at any zoom level instead of being blended into the page.
All of this happens in a Web Worker on your own device using pdf-lib. Nothing is uploaded, and the original file on your disk is left untouched.
Frequently Asked Questions
Can the watermark be removed?
A watermark drawn on top of a page can be removed by someone with the right PDF editor, it is a visual deterrent, not encryption. If you need to control access, use the Protect PDF tool to add a password as well.
Will it cover my content?
At the default 20% opacity the text sits behind your content visually and stays readable. Lower the opacity for a lighter mark, or use the footer layout to keep the page completely clear.
Can I use an image or logo?
Not yet, this tool stamps text only. For a logo, add it to your document before exporting to PDF.
Which characters are supported?
Standard Latin characters. Accented letters are supported, but non-Latin scripts such as Arabic or Chinese cannot be drawn with the built-in PDF fonts.
Does it work on scanned PDFs?
Yes. The watermark is drawn over the page image just like any other page content.