Add SAMPLE Watermark to PDF

"SAMPLE" watermarks are used in proposals, portfolios, and previews to indicate that the document is provided for evaluation only and does not represent a final or deliverable version. This tool stamps a diagonal "SAMPLE" watermark across every page of your PDF.

This is common practice for freelancers and agencies sharing work with prospective clients before payment: the client can evaluate the content and layout, but the watermark signals that the final deliverable will be provided after the project is confirmed.

The watermark text, size, and opacity are configurable. A semi-transparent gray or red watermark is the most common style. The watermark text can also be customized — use "PREVIEW", "PROOF", or any text that fits your workflow.

All processing is local using pdf-lib. No files are uploaded to any server.