Add Watermark to PDF

Stamping a watermark across a document is one of the simplest ways to communicate a document's status at a glance — "CONFIDENTIAL" across an internal report, "DRAFT" across a contract that hasn't been signed yet, or a company name across pages shared with a client before a deal closes. Most free watermarking tools online require uploading the document to a server first, which is an awkward tradeoff for exactly the kind of files people watermark — drafts, contracts, and internal reports that are sensitive by definition.

This tool reads your PDF directly in the browser and stamps your chosen text onto every page using the same in-memory PDF engine used by the rest of AllCoreKit's PDF tools — no upload before you configure the watermark, and no upload after you download the result. The text is drawn directly into the page content, not layered on as an image, so it stays sharp at any zoom level and the file size barely changes.

You control the text, its position (any of nine anchor points across the page, from a corner to dead-center), font size, color, opacity, and rotation angle — the classic diagonal 45° "CONFIDENTIAL" look is the default, but a horizontal footer-style stamp or a subtle corner mark work just as well. A live preview shows exactly how the watermark will sit on the page as you adjust each setting, so there's no guessing and no repeated trial-and-error downloads.

Once the settings look right, one click stamps every page of the document and hands you back a new PDF — the original file is never modified, and nothing about the process ever touches a network request.