ThePDFNinja

Watermark PDF files

Stamp text or an image watermark on your PDF. Control opacity, position, and typography — mark your document as yours.

Select PDF files

or drop PDFs here

✓ 100% Free
✓ No signup required
✓ No email required
✓ Works in browser — no install
✓ Files deleted in 1 hour
✓ 256-bit SSL encrypted
✓ Works on Mac, Windows, iPhone, Android
✓ No watermark
✓ Unlimited conversions

How to watermark pdf online free

1

Step 1

Use CONFIDENTIAL, DRAFT, or your company name

2

Step 2

Lower opacity (0.1-0.3) gives a subtle watermark

3

Step 3

The watermark appears on every page

Frequently Asked Questions

Is this watermark pdf tool free?

Yes, ThePDFNinja's watermark pdf tool is 100% free to use. There are no hidden fees, subscriptions, or credit cards required.

How do I watermark pdf for free?

Simply upload your document using the box above, configure any necessary options, and our servers will instantly process your file for free.

Do you store my files?

No. All files uploaded to ThePDFNinja are strictly confidential and are automatically and permanently deleted from our servers after 1 hour.

Does this work on Mac, iPhone, and Android?

Yes, as a web-based tool, it works flawlessly across all operating systems and devices, including Mac, Windows, iOS (iPhone/iPad), Android, and Linux.

Will there be a watermark on my file?

Absolutely not. We never add watermarks to your documents.

Why use ThePDFNinja to watermark pdf?

ThePDFNinja provides the fastest, most reliable way to watermark pdf online. Unlike other tools that force you to create accounts, pay subscription fees, or deal with heavy watermarks, our Watermark PDF tool is completely free and accessible directly from your browser.

We prioritize your privacy above all else. Every document uploaded for watermark pdf is processed in an isolated environment using AES-256 SSL encryption. Once your task is complete, the original and processed files are permanently deleted from our servers within 24 hours. We guarantee that your data is never read, analyzed, or shared with third parties.

Whether you are working from a desktop PC, a Mac, or a mobile device, you can easily watermark pdf anywhere, anytime, without installing any software.