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Watermark PDF Online

Apply a diagonal text watermark to every page of a PDF. Type your watermark text, choose the colour and opacity, and PDFKat adds it to each page without uploading your file.

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How to use Watermark PDF Online

  1. 1Upload one PDF file.
  2. 2Enter the watermark text.
  3. 3Choose a colour and adjust the opacity and font size.
  4. 4Select Add Watermark and download the watermarked PDF.

Privacy-first processing

The watermark is applied to your PDF locally in your browser. Files are not uploaded to a PDFKat server.

FAQs

Can I set the opacity of the watermark?

Yes. Use the opacity slider to set how visible the watermark is, from 10% (very faint) to 60% (clearly visible).

Is the watermark on every page?

Yes. The watermark text is placed diagonally at the centre of every page in the PDF.

Can I choose the watermark colour?

Yes. Choose from Grey, Red, Blue, or Black colour presets.

Will the watermark be permanent?

The watermark is embedded into the PDF pages. It can be removed with specialised PDF editing software, but it will appear in all standard PDF viewers.

Related PDF tools

Merge PDFCombine multiple PDF files into one clean document.Rotate PDFTurn pages clockwise and download a corrected PDF.Add Page NumbersStamp page numbers onto every page of a PDF.Protect PDFAdd a password to lock a PDF from unauthorized access.

Best for quick document work

PDFKat is built for simple everyday PDF tasks on desktop and mobile browsers. For best results, use files that are not password-protected or restricted.