PDF Watermark

This free online PDF watermark tool stamps a custom text watermark — CONFIDENTIAL, DRAFT, SAMPLE, a company name, a client name, anything you type — across every page of a PDF, with a live preview so you see exactly how it will look before committing to anything. It's built for the moment a document is about to leave your hands: a proposal going out for review, a contract draft circulating before signature, a sample deliverable shared with a prospective client, or internal material that needs a clear visual reminder of its status.

Two layouts cover the two real reasons people add a watermark. "Centered" places one large, angled watermark across the middle of each page — bold enough to read at a glance but not so intrusive that the underlying content becomes unreadable, ideal for a simple DRAFT or SAMPLE stamp. "Tiled" repeats the watermark in a grid across the entire page instead, which is what actually deters someone from cropping or screenshotting around a single mark — the standard approach for protecting sensitive or confidential material that shouldn't be copied or redistributed without attribution.

Every visual property is yours to control before export: pick any color with the built-in color picker, dial opacity from a barely-there hint to a bold, unmissable stamp, scale the text size up or down, and set the rotation angle — the classic 45° diagonal or dead flat, whichever reads better against your layout. The live preview updates instantly against your actual first page as you adjust each setting, so there's no guessing and no repeated trial-and-error downloads just to check how it looks.

The watermark is written as real PDF content using pdf-lib, directly onto each page alongside the original text and graphics — not baked into a flattened image, so the underlying document keeps its original text, quality and selectability completely intact underneath the stamp. Rendering the preview and generating the final file both happen entirely in your browser, so the document is never uploaded anywhere, making this a safe option for contracts, financial documents or anything else you'd rather keep private while marking it clearly.