Free PDF Watermark Tool
Stamp text like CONFIDENTIAL or DRAFT diagonally across every page — free for 3 files per day; nothing is stored.
How a watermark actually gets stamped onto a page
This tool generates a brand-new, blank PDF page sized to exactly match each source page's dimensions, draws your watermark text diagonally across it, and then merges that overlay directly into the original page's content — a standard PDF technique for stamping content on top of an existing page without touching what's already there. Because the overlay is generated fresh for every page based on that page's own size, it works correctly even across a document with mixed page sizes, and because it operates purely on the page's visual layer, it doesn't care whether the underlying content is live text or a flattened scanned image.
Choosing opacity is mostly a legibility trade-off: low opacity (10–20%) keeps the underlying document easy to read with the watermark as a subtle background cue, while higher opacity (50%+) makes the watermark impossible to miss — closer to a true "do not distribute" stamp than a background mark.
Frequently Asked Questions
Where does the watermark appear on the page?
It's stamped diagonally across the center of every page, the classic "CONFIDENTIAL" or "DRAFT" look. Position and rotation aren't customizable yet — opacity and font size are.
Can I remove a watermark this tool added?
Not currently — the watermark is merged directly into the page content, the same way any PDF watermark works. Keep your original file if you might need an unwatermarked copy later.
Will it work on scanned or image-only PDFs?
Yes — the watermark is stamped on top of the page as a separate layer, so it works regardless of whether the underlying page is text or a scanned image.
What opacity should I use?
Lower opacity (10–20%) keeps the underlying document easy to read with the watermark as a subtle background cue. Higher opacity (50% and up) makes it much more prominent — closer to an unmissable "do not distribute" stamp than a background mark.
Is my document kept on the server?
No. The file exists in server memory only for the moment it takes to process, then it's discarded. Nothing is retained or shared.