Add a text watermark to PDF — offline & private

Stamp CONFIDENTIAL, DRAFT, or your brand name across every page — with full control of angle, opacity, color, and font size, and a live visual preview before you commit. Watermarking runs locally in your browser with pdf-lib, so your file never leaves your device.

How to Add a text watermark to PDF — offline & private

1. Step 1. Upload your PDF (it stays on your device).
2. Step 2. Type your watermark text (e.g. CONFIDENTIAL or DRAFT).
3. Step 3. Tune the angle, opacity, color, and font size using the live preview.
4. Step 4. Execute — the stamp is applied locally in your browser — then download the watermarked PDF.

Frequently asked questions

Is the watermark applied to every page?

Yes — the text is stamped across all pages of the document in a single operation, generated entirely in your browser.

Can I make the watermark diagonal and semi-transparent?

Yes — angle and opacity are both adjustable; the classic look is 45° at 25% opacity.

Is my file uploaded to a server when watermarking?

No. Watermarking is 100% offline — the PDF is processed in your browser memory and never sent anywhere. Encrypted files are skipped with a warning.

Can I use an image logo instead of text?

This tool stamps text. For logo watermarking, place your logo in a PDF and use the Overlay / Stamp tool.