Add Watermark to PDF: Complete Guide
Protect your intellectual property, mark documents as confidential, or brand your content with custom text watermarks — all within your browser, free of charge.
What is a PDF Watermark?
A PDF watermark is a semi-transparent text or image that is overlaid on every page of a PDF document. It serves multiple purposes: indicating document status (e.g., "DRAFT", "CONFIDENTIAL"), asserting ownership, or deterring unauthorized distribution. Watermarks are an essential tool for anyone who shares sensitive documents.
Unlike editing the content of a PDF, adding a watermark simply draws text on top of the existing page content. The original text, images, and formatting remain completely untouched — the watermark is an additional visual layer that communicates important metadata at a glance.
Why Watermark Your PDFs?
Protect Ownership
Mark documents with your company name or logo equivalent to deter unauthorized copying and redistribution of proprietary content.
Indicate Status
Clearly mark documents as "DRAFT", "REVIEW", "APPROVED", or "CONFIDENTIAL" so recipients immediately understand the document's purpose.
Prevent Misuse
By visually branding a document, it becomes difficult for anyone to present it as their own or use it outside its intended context.
Customization Options Explained
- Font Size (10–150px): Control how large the watermark text appears. Smaller sizes (20–30px) work well for subtle branding, while larger sizes (80–150px) create a bold visual statement.
- Opacity (5–100%): Adjust how transparent the watermark is. A low opacity (20–30%) keeps the document readable while still visible. Higher opacity (60%+) makes the watermark prominent.
- Color: Choose from five preset colors — gray (subtle), red (urgent), blue (professional), green (approved), or black (formal).
- Rotation: Choose diagonal (45°) for the classic look, horizontal for header-style placement, vertical for side markings, or reverse diagonal.
- Position: Place the watermark at the center, any corner, or tile it across the entire page for maximum coverage.
Privacy & Security
ToolMini processes everything in your browser. When you upload a PDF, it stays on your computer. The pdf-lib library (an open-source JavaScript library) manipulates the document right inside your browser tab. No file is ever sent to any server. This makes our tool:
- 100% Private: We can't see your documents even if we wanted to — the data never reaches us.
- Blazing Fast: No upload/download time means even large files process in seconds.
- Works Offline: Once the page is loaded, you can disconnect your internet and still use the tool.