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100% Client-Side Privacy
pdf-lib (Client-Side)
Add Watermark to PDF
Protect your documents by overlaying customizable watermark text such as "CONFIDENTIAL", "DRAFT", or your company name diagonally or horizontally with adjustable transparency.
Select or drop your PDF document here
Processed locally in your browser. 100% private.
Browse Fileor Paste (Ctrl+V)
Supported: .pdf, application/pdf (Max 80 MB)
How to Use Add Watermark to PDF
Follow these easy steps to process your file right in your browser.
1Step 1
Upload your PDF document
Select the PDF document you wish to watermark.
Instant local processing
2Step 2
Configure watermark text and style
Type your custom watermark text (e.g. "CONFIDENTIAL"), adjust font size, angle (45° diagonal or horizontal), and opacity (10% - 80%).
Instant local processing
3Step 3
Apply watermark
Click "Apply Watermark". The vector text layer is drawn across all pages.
Instant local processing
4Step 4
Download watermarked PDF
Save your protected PDF document.
Instant local processing
Frequently Asked Questions
Common questions about Add Watermark to PDF and browser processing.
No, because the opacity is adjustable (default 25%), the underlying text remains readable while clearly displaying the stamp.
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