Add Watermark

A watermark stamps text such as "CONFIDENTIAL", "DRAFT" or your company name across every page of a PDF. It deters unauthorised copying, marks the status of a document, and reinforces ownership.

ColaPDF lets you set the watermark text, position, opacity, size and rotation, then applies it to all pages at once — without uploading the file. The semi-transparent overlay sits over the content while keeping the underlying text readable.

How it works

1. Upload your PDF
2. Type your watermark text and choose position, size and opacity
3. Preview the watermark in the live preview panel
4. Click Add Watermark and download

Tips

• Lower the opacity so the watermark is visible but does not obscure the text underneath.
• A diagonal 45-degree angle is the classic, hard-to-remove watermark style.
• Use a light grey colour for a subtle mark, or red for a strong "DRAFT"/"CONFIDENTIAL" stamp.

Frequently asked questions

Can I control the watermark opacity?

Yes — use the opacity slider to make it as subtle or bold as you want.

Can I position the watermark anywhere?

Yes — choose from diagonal, centre, tile, or specific corners.

Are files uploaded?

No. Everything runs in your browser.

Can I add an image watermark instead of text?

For image stamps use the Add Image Stamp tool.