PDF Watermark Tool — Add Text Watermarks
Add custom text watermarks to any PDF file directly in your browser. See a live preview of the watermark before you download. Customize text, font size, color, opacity, rotation, and position. 100% private — your files never leave your device.
How to Add a Watermark to PDF
Select your PDF file, type your watermark text (e.g., "CONFIDENTIAL", "DRAFT", "SAMPLE"), choose the font size, opacity, color, angle, and position. A live preview instantly shows how the watermark will look on Page 1 of your PDF — flip through all pages with the navigation buttons. When satisfied, click "Add Watermark & Download" to save the result. Everything happens in your browser using pdf-lib.js — your PDF is never uploaded to any server.
Why Watermark Your PDF Documents
Watermarks protect your documents from unauthorized use and distribution. Mark draft documents as "DRAFT" to prevent premature sharing. Label confidential contracts and reports. Add "SAMPLE" to preview documents. Watermarks make it clear that a document has restrictions or is not the final version, reducing liability and miscommunication.
Privacy-First PDF Watermarking
Most online PDF watermark tools upload your files to their servers, exposing sensitive documents to third parties. This tool is different — pdf-lib.js and PDF.js both run entirely in your browser. Your PDF is read into memory, the watermark is previewed and applied using JavaScript, and the result is downloaded directly. Zero network requests are made with your file data.
Watermark Text Ideas for Different Use Cases
Legal: CONFIDENTIAL, PRIVILEGED, DO NOT COPY. Business: DRAFT, INTERNAL USE ONLY, FOR REVIEW. Education: SAMPLE, PREVIEW, STUDENT COPY. Photography: Your name or studio name as a watermark on PDF portfolios. This tool supports any custom text with full control over appearance.
Getting the Most from This Tool
Use the live preview to experiment with different opacity and rotation settings before downloading. For subtle watermarks, try 15-25% opacity in gray. For clearly visible marks, use 40-60% opacity in red or black. The diagonal (-45°) angle is the industry standard for document watermarks. All processing happens in your browser, so your data stays private and the tool works even without an internet connection after the initial page load.