Watermark PDF
Add custom text watermark to PDF files online for free. Set custom text, opacity, and font size.
How to use Watermark PDF
- Upload your PDF document into the watermark tool drop zone.
- Enter custom watermark text or upload a transparent PNG logo image.
- Adjust watermark opacity, font size, rotation angle, and page position settings.
- Click "Execute Watermark PDF" to stamp all document pages.
- Download your watermarked PDF file.
Technical Details & Specifications
Watermarks are rendered as vector text streams or image XObject overlays with custom transformation matrices (opacity, scale, rotation) injected into page content streams via pdf-lib.
Frequently Asked Questions
Can I add both text watermarks and image watermarks on AllPDFTool?
AllPDFTool's Watermark PDF tool supports both custom text watermarks with custom fonts and graphic image logos (PNG, JPG).
Will watermarking overwrite or alter my existing PDF text?
AllPDFTool stamps watermarks onto a separate transparent canvas layer above or behind existing page content without corrupting document text.
Are my document contents kept private when adding watermarks?
AllPDFTool processes all document watermarking locally inside your browser memory without uploading files to remote servers.
Can I adjust watermark transparency and rotation on AllPDFTool?
AllPDFTool provides real-time option sliders allowing you to set watermark opacity percentages and diagonal rotation angles.