✦ Free · No Upload · Browser-Based
Add Watermark to PDF — Free Online, No Upload
Stamp any text as a diagonal watermark across every page. Customise the text, opacity, and size to suit your document.
✓ 100% Free
✓ No file uploads
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⚡ Works instantly
40%
How to Add a Watermark to a PDF
Watermarking PDF documents is important for protecting your work, marking drafts, or branding documents before sharing them. PDFZen4u adds diagonal text watermarks to every page of your PDF, with full control over the wording, transparency, and font size.
1
Upload Your PDF
Drop your PDF into the upload area.
2
Set Your Watermark
Type your watermark text (e.g. CONFIDENTIAL, DRAFT, DO NOT COPY), set the opacity percentage, and adjust the font size to suit your document's proportions.
3
Download Watermarked PDF
Click Add Watermark and the stamped PDF downloads immediately with the watermark applied to every page.
Frequently Asked Questions
For a subtle background watermark, 20–30% opacity works well. For a more prominent mark that's clearly visible, try 40–60%. For a very light draft mark, 10–15% is appropriate.
PDFZen4u embeds the watermark as a standard PDF text element. Removing it would require PDF editing software. For security, consider using higher opacity to make removal more difficult.