How to Add a Watermark to PDF
Upload your PDF file and enter your watermark text. Our tool overlays this text across all pages using your chosen settings—font size, opacity, rotation angle, and color. The watermark appears centered on each page, positioned diagonally for maximum visibility without obscuring content.
Adjust the opacity slider to balance visibility against readability. A 30% opacity creates a subtle background watermark, while 80% makes the text prominently visible. The rotation angle (typically 45°) positions text diagonally, a common convention for document watermarks. Choose colors that complement or contrast with your document content.
Processing completes in seconds for most documents. The watermarked PDF downloads with your text embedded on every page. Unlike some tools that add watermarks as separate layers, our overlay method integrates the text directly into the page content for reliable display across all PDF viewers.
Why Add Watermarks to PDFs?
Watermarks serve multiple purposes: copyright protection, document status indication, and brand visibility. A 'CONFIDENTIAL' watermark signals restricted distribution. A 'DRAFT' label prevents confusion with final versions. Company logos or names reinforce brand presence on shared documents.
Legal documents, contracts, and intellectual property benefit from visible ownership markers. Marketing materials and presentations can carry brand watermarks for consistency. Academic papers often use watermarks to indicate pre-publication status. Any document requiring identification or protection can benefit from a clear watermark.
Common Watermark Use Cases
Businesses watermark internal documents with 'CONFIDENTIAL' or 'INTERNAL USE ONLY' to control distribution. Publishers add copyright notices to preview copies. Photographers watermark portfolio PDFs to deter unauthorized use. Real estate agents watermark property documents with their branding.
Legal teams use 'DRAFT' watermarks during document review. HR departments watermark policy documents for version control. Architects and engineers mark preliminary drawings with status indicators. Event organizers watermark tickets and passes for authenticity.
Consider watermark placement carefully—visible enough to serve its purpose, but not so prominent that it interferes with document readability. Our opacity and size controls help you find the right balance for your specific needs.
Key Features of Our PDF Watermark Tool
- Custom text watermarks with adjustable font size (12-200pt)
- Opacity control from subtle (10%) to prominent (100%)
- Rotation angle for diagonal or horizontal placement (-90° to 90°)
- Full color customization with color picker
- Applies watermark to all pages in the document
Technical Details: PDF Watermarking
Our watermarking uses Apache PDFBox to render text directly onto PDF pages. The text is drawn using Helvetica Bold font with configurable size and color. An extended graphics state controls opacity (alpha transparency), allowing the watermark to blend with underlying content rather than completely obscure it.
The watermark applies a transformation matrix for rotation and centering. Each page receives the same watermark treatment, positioned relative to the page's media box dimensions. This ensures consistent appearance across pages of different sizes within the same document. The resulting PDF maintains full compatibility with standard PDF viewers.
Related PDF Tools
- Compress PDF — reduce file size after watermarking
- Merge PDF Files Online — combine multiple PDFs before watermarking
- Split PDF — extract pages to watermark separately
- Edit PDF — add text and annotations alongside watermarks
- Unlock PDF — remove restrictions before watermarking