Add Watermark to PDF Online Free (Text or Image)
Stamp text or logo watermarks across all or selected pages of your PDF documents.
How it works step by step
- 01Select the PDF file you want to watermark.
- 02Choose text (e.g., CONFIDENTIAL, DRAFT) or upload a logo, and adjust opacity and angle.
- 03Click Apply Watermark and download your protected PDF instantly.
Technical specs & privacy
Text or Image Logo Watermarks
Add legal notices like CONFIDENTIAL or DRAFT, or stamp your company PNG logo with transparency.
Diagonal Center or Full Tiled Grid
Position a classic 45° diagonal stamp across the page or tile repeated watermarks across the entire sheet.
Customizable opacity & page ranges
Fine-tune opacity so your original text stays easy to read, and choose whether to stamp all pages or a custom range.
| Supported input formats | 1 PDF FILE |
|---|---|
| Output target format | WATERMARKED PDF |
| Conversion engine | pdf-lib & PDF.js 2x Canvas (in-browser local) |
| Storage & Privacy | 100% Local · Files never leave your device |
Frequently asked questions
How do I add a watermark to a PDF for free?
Upload your PDF, enter your watermark text or upload a logo, select your preferred rotation and opacity, then click Download.
Will the watermark obscure the original text?
No, you can set a subtle opacity (such as 15% or 25%) so the background watermark protects the file without hindering readability.
Can I apply the watermark only to specific pages?
Yes, you can choose all pages or specify custom ranges like "1-3, 5".
Is my document private and secure?
Yes, 123FileTools processes your PDF entirely within your browser. Your files are never uploaded to any server.
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