◈ Watermark PDF
Protect your documents with a diagonal text watermark. Set the text and opacity.
Drop a file here or click to browse
PDF · processed privately on your device
Watermark PDF stamps a diagonal text mark across every page — think DRAFT, CONFIDENTIAL, or your company name. Set the words and opacity, and Slate overlays them locally so your branding or warning travels with the file. No uploads, no watermark from us.
How to watermark pdf
- Drop in your PDF.
- Type your watermark text and pick an opacity.
- Download the watermarked PDF.
Frequently asked questions
Can I control how visible the watermark is?
Yes. Choose an opacity from 10% for a subtle mark up to 50% for a bold one.
Does the watermark appear on every page?
Yes. The diagonal text is stamped across all pages for consistent protection.
Are my files uploaded to a server?
No. Slate processes your PDF entirely in your browser. Your files never leave your device, which is faster and far more private than typical online tools.
Is Watermark PDF really free?
Yes. Watermark PDF is completely free with no signup and no limits. Slate is funded by unobtrusive ads, not subscriptions.