PDF Watermark

Add a text watermark to your PDF

Click or drop a PDF here

About PDF Watermark

PDF Watermark stamps a diagonal, semi-transparent text watermark across the center of every page, using the pdf-lib library entirely in your browser — your file is never uploaded to a server. You can customize the text and its opacity; there's no image watermark option, and the rotation (45°), color (gray), and position (page center) are fixed.

How to use PDF Watermark

  1. 1Click the upload area and select a PDF file from your device.
  2. 2Type the watermark text (defaults to "CONFIDENTIAL").
  3. 3Adjust the opacity slider to your preference.
  4. 4Click 'Add Watermark', then 'Download' to save the result.

Frequently Asked Questions

Is PDF Watermark free to use?

Yes, it's completely free with no signup required.

Can I add an image watermark, like a logo?

No — only text watermarks are supported; there's no option to upload an image.

Can I change the watermark's color, angle, or position?

No — the watermark is always gray, rotated 45°, and centered on the page. Only the text and opacity are adjustable.

Can I watermark multiple PDFs at once?

No, only one file at a time — upload and process additional files separately.

Tips & Tricks

  • Lower opacity values (around 20-30%) keep the underlying content easy to read while still visibly marking the page.
  • Since the position and angle are fixed, try a few different lengths of watermark text to see what looks best on your document.
  • The font size automatically scales to the page dimensions, so the watermark looks proportionate across different page sizes.
  • For a logo or image watermark, you'll need a different tool, since only text is supported here.