Add a watermark to your PDF

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Add a diagonal text watermark to every page of your PDF — ideal for marking drafts, confidential documents, or proofs before sharing.

Frequently asked questions

Can I customise the watermark text?

Yes — enter any text, adjust font size, and Smash applies it diagonally across every page.

Can I control the watermark colour or opacity?

The watermark uses a semi-transparent grey by default, readable on both light and dark page backgrounds.

Can I add an image watermark instead of text?

Text watermarks only for now. Image watermarks are a planned feature.

Will the watermark significantly increase file size?

Minimally — text watermarks add only a small amount of PDF vector content per page.

Can someone remove the watermark?

A user with PDF editing software could attempt removal. For stronger protection, combine watermarking with password encryption.