Add a Watermark to PDF

Adding a watermark to a PDF communicates the document's status at a glance — "DRAFT", "CONFIDENTIAL", "SAMPLE", or any custom text you choose. This tool stamps a diagonal text watermark across every page of your PDF.

Configure the watermark text, font size, and opacity. A semi-transparent watermark (40–60% opacity) is visible enough to serve its purpose without obscuring the document content behind it.

The watermark is applied using pdf-lib running in your browser. No file is uploaded to any server. This is important for confidential documents where even a watermark reveals the existence of sensitive content — your files stay on your device throughout the process.

The resulting PDF preserves all original text, images, and formatting, with the watermark layer added on top.