OomTools

Add Watermark to PDF

Stamp custom text across every page of a document, with control over colour, size, opacity and rotation. It uses pdf-lib in your browser, so the file never leaves it — perfect for marking something DRAFT, CONFIDENTIAL, or with your own brand.

  • 100% free
  • Private & safe
  • Runs in your browser

Your files are processed securely in your browser and are not uploaded to our servers.

Why use Add Watermark to PDF?

Add Watermark to PDF works on your documents locally, so you get the result in seconds with no watermarks, no sign-up and no files leaving your device.

  • 100% private: files are processed in your browser and never uploaded.
  • Completely free, with no account, no watermarks and no usage limits.
  • Handles PDF (.pdf); Text watermark on all pages.
  • Add a PDF file.
  • Works on any device — desktop, tablet and phone — and is fully keyboard accessible.

How to use Add Watermark to PDF

  1. Add a PDF file.
  2. Enter the watermark text and choose colour, size, opacity and rotation.
  3. The watermark is applied to every page.
  4. Download the watermarked PDF.

Examples

  • Marking a contract draft as 'CONFIDENTIAL'.
  • Adding a diagonal 'SAMPLE' across a preview document.

Supported formats & limits

  • PDF (.pdf)
  • Text watermark on all pages

Limitations

  • Only text watermarks are supported (no image/logo).
  • The watermark is drawn over existing content and becomes part of the page.
  • Encrypted PDFs must be unlocked first.

Frequently asked questions

Does the watermark go on every page?

Yes. The text is stamped on all pages of the document.

Can I use a logo image?

This tool adds text watermarks; image overlays are not supported here.

Is my PDF uploaded?

No — the watermark is applied locally in your browser.

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