Watermark
Lay text across every page at the angle and opacity you want.
About Watermark
Watermark lays text diagonally across every page at the opacity, size and angle you set. Typically used to mark a document as DRAFT, CONFIDENTIAL or with a recipient’s name so a leaked copy can be traced. The text is drawn into the page itself rather than added as an annotation, so it survives flattening and printing.
How to use it
- Drop in the PDF.
- Type the watermark text and set opacity, size and angle. Around 15% opacity stays readable underneath.
- Click Add watermark.
Questions
Does a watermark protect my document?
Only as a deterrent. It marks a copy visibly but does not encrypt or lock anything — a determined person can cover or crop it. Real protection needs encryption, which pdf-lib cannot do.
What opacity should I use?
10–20% is the usual range: clearly visible without making the text underneath hard to read. Go higher only if deterrence matters more than legibility.
Can I use an image or a logo instead of text?
Not currently — this tool draws text only.
Watermark is free and runs entirely in your browser. No account, no upload, no watermark, no limit on use.