Boneyard Tools

Add a Watermark to a PDF

Stamp a diagonal text watermark such as CONFIDENTIAL or DRAFT across every page of a PDF. Pick the text, opacity, font size, color, and angle, then download the marked file. Everything runs in your browser with pdf-lib, so the PDF never leaves your device.

How to watermark a PDF

  1. Drop a PDF in, or click to browse.
  2. Type the watermark text and adjust opacity, size, color, and angle.
  3. Click add watermark and download the marked PDF.

Examples

Mark a contract as confidential

A 12-page contract, text CONFIDENTIAL at 30% opacity, 45 degrees
The same PDF with a translucent diagonal stamp on every page

Frequently asked questions

Is my PDF uploaded anywhere?

No. The watermark is drawn entirely in your browser with pdf-lib. The PDF never leaves your device, so confidential documents stay private.

What text and styling can I use?

Type any single line of text, then set its opacity, font size, color, and angle. A diagonal 45 degree stamp is the classic look, but you can also lay it flat at 0 degrees.

Does the watermark go on every page?

Yes. The same text is stamped, centered, on every page of the document in one pass. There is no per-page configuration.

Can the watermark be removed later?

It is drawn into the page content, not stored as a separate layer, so it is not a one-click removal. It is meant to mark a document, not to encrypt or lock it.

What if my PDF is password protected?

If a PDF opens without a password in your viewer, it will watermark here. Documents that require a password to open are not supported.

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