Watermark PDF
Stamp a diagonal text watermark (like "COPY" or "CONFIDENTIAL") across every page.
This tool stays free by showing a short ad for larger files: 20 pages or fewer is free, 21-50 pages = 1 ad, 51-100 pages = 2 ads, 100+ pages = 3 ads.
How it works
The text is drawn diagonally across the center of every page at the opacity you choose, without re-rendering the page content.
Is my file uploaded anywhere?
No — everything happens locally in your browser. Your PDF never leaves your device.