PDF Watermark
Stamp CONFIDENTIAL, DRAFT or your own text across the pages of a PDF. Set the opacity, angle and colour. Runs in your browser — the file is never uploaded.
- Free, no sign-up
- REST + MCP
- Updated
- Reviewed by Olgun Ozoktas
Why Use Our PDF Watermark Tool?
A watermark is text drawn on top of a page at low opacity, rotated so it crosses the content. That is all it is, and knowing that tells you what it is good for.
It is good at signalling. A reader who opens a page stamped DRAFT knows immediately not to treat it as final, and a page stamped CONFIDENTIAL carries its handling instruction with it wherever it is forwarded. That signal survives printing, screenshotting and forwarding, which is more than can be said for an email footer.
It is not good at preventing anything. The original content is untouched underneath — that is the point of drawing over it rather than rewriting it — so the text stays selectable and the page stays intact. A watermark can be removed by anyone with a tool like this one. Treat it as a label, never as a lock.
The default size is computed rather than fixed: the text is scaled so it spans the page's diagonal. A mixed document of portrait and landscape pages therefore gets a mark that looks deliberate on both, instead of one that is right on A4 and comically wrong on a wide sheet.
How it compares
Most online watermark tools upload the PDF. A document you are about to mark CONFIDENTIAL is precisely the one that should not be sent to a third party to have the label applied. This page never sends it anywhere.
Desktop editors do this and much more, at the cost of an install and often a subscription. If you also need to sign or redact, PDF Editor has the full annotation toolkit, and PDF Page Numbers is the other common finishing step before a document goes out.
PDF Watermark Tips
- Low opacity is usually right. Around 0.15 marks the page clearly and still lets the text underneath be read.
- The default 45 degree angle spans the page diagonally, which is harder to crop out than a horizontal line.
- Leave the size at its default and the text is scaled to the page, so it looks the same on every sheet whatever their sizes.
- Leave Pages empty to stamp everything. Name pages when only a section needs marking.
- The text is drawn over the existing content, so the page underneath is unchanged and still selectable.