Free Add Watermark to PDF
Add custom text watermarks to every page of your PDF — CONFIDENTIAL, DRAFT, or any text. No upload.
Text watermarks mark documents as CONFIDENTIAL, DRAFT, SAMPLE or any custom label, making it visually clear that a document is preliminary or restricted. The watermark text is embedded directly into the page content using pdf-lib — it is part of the PDF structure, not a floating overlay — making it persistent across all PDF viewers. Choose colour, opacity, size and position.
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How it works
Select PDF
Click or drag & drop. Stays on your device.
Set options
Adjust settings — browser processes locally.
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What Is a PDF Watermark Used For?
PDF watermarks are used to mark documents as confidential, draft versions, samples, or internal use only. They appear across the page content, making it clear that the document is not final or should not be distributed. Businesses use watermarks on contracts, legal documents, reports and presentation drafts.
OneConvert adds the watermark text directly to the PDF page structure using pdf-lib — entirely in your browser. No upload, no server processing. Your document stays private.
A Watermark Is a Visual Mark, Not Protection
This tool draws text onto each page as part of the page content — a real drawing operation in the content stream, positioned and rotated, usually with reduced opacity so the underlying text stays readable. That is the same mechanism a word processor uses when it stamps DRAFT across a document.
Because the mark becomes ordinary page content, it survives printing, screenshotting and conversion to images, and it cannot be toggled off in a viewer the way an annotation layer can. Anyone opening the file sees it. For its intended purpose — signalling status, marking a copy as confidential, discouraging casual redistribution — that is exactly right.
It is not a security control, and it is worth being clear about that. The watermark is a drawing instruction sitting alongside every other drawing instruction in the content stream; someone with a PDF editor can locate and remove it. Nor does it encrypt, restrict copying, or prevent editing. If you need the document itself protected, that requires PDF encryption with permissions set by a full PDF application. Use a watermark to communicate intent, not to enforce it.