Skip to main content
KioTools
  • +100 Tools
  • 100% Free
  • 0 Pop-up Ads
  • No Sign-up
  • Runs locally

Related Tools

Add Page Numbers to PDF

Stamp page numbers with a live preview.

Crop PDF

Trim margins off every page, by hand or automatically.

Dark Mode PDF

Invert a PDF's colours for comfortable night reading.

PDF Watermark

What is this tool?

A PDF watermarker built on pdf-lib. It draws your text or image, centred and turned 45°, onto every page or just the pages you pick, with adjustable size and opacity. The watermark is written into the page content, so it shows in any viewer.

When to use it

  • Marking a document as DRAFT, SAMPLE or CONFIDENTIAL before it circulates
  • Putting a company name or copyright notice across a report
  • Stamping a logo on every page of a proposal
  • Watermarking only some pages, such as the appendix
  • Making it clear which copy of a document is the official one

How to use it

  1. 1Drop in a PDF
  2. 2Choose a text or image watermark and set its size and opacity
  3. 3Pick the pages to stamp — click thumbnails, or leave the range blank for all pages
  4. 4Click Apply Watermark
  5. 5Download the watermarked file

Frequently asked questions

Can I use my logo instead of text?

Yes — switch to Image, upload a PNG or JPG, and set the stamp width.

Can I watermark only some pages?

Yes — click the page thumbnails or enter a range like 1, 3-4. Leave it blank to stamp every page.

Can the watermark be removed afterwards?

It is drawn into the page content, so a PDF editor can remove it. A watermark deters casual reuse; it is not a security feature.

Is my PDF uploaded?

No — it's processed entirely in your browser.