Add a text watermark to a PDF without uploading it
A diagonal DRAFT, CONFIDENTIAL, or COPY stamped across a document tells everyone how to treat it at a glance. This tool draws your chosen text diagonally across every page of a PDF. Semi-transparent and centered, so it is unmistakable without obscuring the content underneath. It uses pdf-lib, pure JavaScript running in your browser, so the document, often a contract or internal report precisely because it needs a CONFIDENTIAL mark, is watermarked locally and never uploaded. The original text and images of the page are preserved; the watermark is drawn on top.
How it works
- Drop your PDF below.
- Type the watermark text. CONFIDENTIAL by default, or anything you like.
- Download the watermarked PDF, stamped on every page.
Frequently asked questions
Where does the watermark appear?
The text is drawn diagonally (at 45°) across the center of every page, sized to the page and made semi-transparent so the underlying content stays readable. Every page in the document gets the same mark.
Can the watermark be removed by whoever receives it?
Honestly, a watermark is a visual deterrent, not tamper-proofing. A determined person with the right software could remove it. It is meant to communicate status (draft, confidential, copy), not to lock the document. To restrict access, encrypt it with the Protect PDF tool.
Is my document uploaded to add the watermark?
No. The watermark is applied by pdf-lib in your browser tab, with no upload step. Documents that warrant a confidential stamp are exactly the ones that should stay on your device, and they do.
Does watermarking change the rest of the page?
No. The existing text, images, and layout are untouched; the watermark is simply drawn over them. Text in the document stays selectable and images keep their resolution.