How to Add a Watermark to a PDF

Quick answer: Overlay text like "CONFIDENTIAL" or "DRAFT" diagonally across every page of a PDF. Open PDF 水印 — everything runs locally in your browser, and files never leave your device.

Steps

1. Upload the PDF to the Watermark tool.
2. Enter the watermark text and pick font size, color, and rotation.
3. Set opacity — 15–25% keeps body text readable underneath.
4. Download the stamped PDF.

Important notes

• Watermarks sit between the background and the text layer, so they never obscure content at reasonable opacity.
• A visible watermark is a deterrent, not protection — it does not encrypt or restrict copying.

Common questions

Can I use an image logo instead of text? Yes, upload a transparent PNG for the cleanest result.

Can I apply it to only some pages? Yes, restrict the watermark to a page range.