Add Watermark to PDF Online - Text Watermark Free
Add custom text watermarks to your PDF files online. Customize opacity, angle, color, and font size. 100% free and secure.
Select PDF file to watermark
Stamp custom text across all pages
How to Watermark PDF Online in 3 Easy Steps
Fast, simple, and processed right inside your browser without queue times.
Upload PDF Document
Select the document you want to stamp with a watermark.
Customize Watermark
Type your text (e.g., CONFIDENTIAL, DRAFT, SAMPLE) and adjust angle & opacity.
Apply & Download
Click Add Watermark to download your branded PDF.
Why Use MergPDFOnline for Watermark PDF?
Customizable Transparency
Set opacity from light subtle stamps to bold prominent security markings.
Diagonal & Position Controls
Rotate stamps at 45 degrees across the entire page for maximum protection.
Protect Your Intellectual Property
Watermarking documents is standard practice for drafts, contracts, proposals, and proprietary research to mark ownership and confidentiality.
Frequently Asked Questions
100% Privacy Guarantee
Files never leave your device. All computations happen in your web browser.