Confidential stamp
Stamp a diagonal "CONFIDENTIAL" watermark on every page.
Confidential stamp is a free tool that runs entirely in your browser. Stamp a diagonal "CONFIDENTIAL" watermark on every page. Marking and protecting documents helps you control how they’re shared, printed and reused. Because everything happens locally with pdf-lib and pdf.js, your files are never uploaded to a server — Confidential stamp works instantly, even offline, and keeps every document completely private, with no account, no watermarks and no file-size limits.
How to use Confidential stamp
- 1Open the Confidential stamp tool and drop in your PDF, or click to choose it.
- 2Press Run — there are no settings to fuss with.
- 3Download your result. The whole thing happens on your device, so your PDF never leave your browser.
100% private — nothing is uploaded
Unlike most online PDF tools, Confidential stamp never sends your PDF to a server. Everything is computed locally in your browser with JavaScript, so your documents stay on your device. There's no account, no watermark and no file-size limit — and it even keeps working with your Wi-Fi switched off.