Add Watermark to PDF

Stamp a text watermark — CONFIDENTIAL, DRAFT, your company name — across every page of a PDF. Pick the opacity, size and angle, and download the stamped file. The document is processed on your device and never uploaded.

On-device — downloads its library once PDF Free · no signup

Network notice: Your PDF never leaves your device. The open-source processing library (pdf-lib, MIT license) is fetched from the cdnjs CDN the first time you use the tool.

How to use

Drop a PDF onto the drop zone or click to browse.
Type the watermark text and pick opacity (subtle to strong), size, and whether it runs diagonally.
Click “Add watermark & download” — every page gets the stamp.

Supported formats

Input: standard (unencrypted) PDF files up to 200 MB.
Watermark: gray text, centered on each page, diagonal or horizontal.

Privacy

Your input is processed in your browser and is never uploaded. The first time you use the tool, your browser downloads its open-source processing library from cdnjs.cloudflare.com — the library is downloaded, your data is not sent. Privacy policy.

Limitations

Watermark text is limited to Latin characters (a limitation of the built-in PDF fonts).
The watermark is drawn over the page content; it is a deterrent, not an irremovable protection.

FAQ

Will the watermark appear on every page?

Yes — the same stamp is placed on all pages at the chosen opacity and angle.

Is my document uploaded to add the watermark?

No. Stamping runs in your browser with the open-source pdf-lib library; the file never leaves your device.

Can a watermark be removed?

A determined person with editing tools can remove any visual watermark. Treat it as labeling, not security — for secrecy, control who gets the file.