Watermark PDF

Stamp custom text — DRAFT, CONFIDENTIAL, your name — across every page, with control over opacity, size, and angle. Runs entirely in your browser.

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Quick Answer

Type any watermark text, then tune opacity, size, and angle. The watermark is drawn on every page of a copy of your PDF — your original file is never modified. Everything runs locally in your browser.

Key Facts

  • Custom text watermark on every page
  • Opacity, font size, and 45° diagonal or flat
  • Grey default or pick a lighter shade
  • Original file untouched — you download a new copy
  • 100% in-browser: no upload, no watermark on the watermark (it is your text)

Frequently Asked Questions

How do I add a watermark to a PDF for free?

Upload the PDF, type your watermark text (e.g. DRAFT or CONFIDENTIAL), adjust opacity and size, and download the watermarked copy. This tool draws the text on every page with the open-source pdf-lib engine directly in your browser — no upload to any server, no signup, no page limits.

Can I make the watermark lighter or darker?

Yes — drag the opacity slider. 15–30% is typical for a subtle background stamp; 50%+ reads as a bold overlay. You can also change the font size and switch between a 45° diagonal (classic draft stamp) and flat horizontal text.

Does the watermark go on every page?

Yes, it is centered on every page of the document. Because page sizes can vary, the position is computed per page so it stays centered even on mixed portrait/landscape documents.

Is this safe for confidential documents?

The file never leaves your device — the tool is a static web page and all processing happens in your browser's memory. There is no server upload step at all, which is exactly what you want for confidential material.