Watermark PDF

Drag and drop, or click to upload a PDF

Watermark PDF stamps your text diagonally across every page of a PDF at a light opacity - no Adobe Acrobat or other software required. It runs on pdf-lib entirely inside this browser tab; the file you upload is never uploaded to a server.

How to use it

  1. Drag and drop, or click to upload a PDF.
  2. Type the watermark text, like CONFIDENTIAL or DRAFT.
  3. Click "Add Watermark & Download" to save a copy with the watermark on every page.

Frequently asked questions

Is my PDF uploaded to a server?

No - the watermark is drawn entirely in your browser using pdf-lib. The file you upload never leaves your device.

Where does the watermark appear?

Diagonally across the center of every page, at a light opacity so the original content stays readable underneath.

Can I use an image or logo instead of text?

Not yet - this tool only adds a text watermark.

Can I change the watermark's color, size, or angle?

Not yet - it's a fixed gray, 45-degree, semi-transparent watermark. Only the text itself is customizable.

Does adding a watermark reduce PDF quality?

No - pdf-lib draws the watermark text directly onto each existing page without re-rendering or recompressing anything else on it.

What's the watermarked file called?

Your original filename with -watermarked added, like report-watermarked.pdf.