Add Watermark to PDF

Overlay a diagonal text watermark — like "CONFIDENTIAL" or "DRAFT" — across every page of a PDF. Adjust the opacity and size, then download the watermarked file.

Click or drag & drop a PDF file

Supported: PDF files

Watermark Text

Opacity: 30%

Font Size: 48px

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Why use Add Watermark to PDF?

This tool overlays a diagonal text watermark across every page of a PDF using pdf-lib, entirely in your browser. Adjust the opacity so the watermark is visible without obscuring the underlying content, and choose a font size that fits your document.

Key benefits

Adjustable opacity so the watermark doesn't obscure content
Applied to every page automatically
Processed entirely in your browser

Features

Diagonal 45° text watermark
Adjustable opacity and font size
Applies to all pages in one pass

Popular use cases

Marking a document as DRAFT or CONFIDENTIAL before sharing
Adding a company name across shared PDFs

How to use Add Watermark to PDF

1
Upload a PDF
Click or drag a PDF file into the upload area.
2
Enter watermark text
Type the text you want overlaid, such as "CONFIDENTIAL" or "DRAFT".
3
Adjust opacity and size
Use the sliders to set how visible and how large the watermark appears.
4
Download the watermarked PDF
Click Add Watermark to download the result.

Frequently asked questions

Can I add an image or logo watermark instead of text?

This version supports text watermarks only. For a logo watermark, consider overlaying it with a PDF editor after adding your text watermark.

Will the watermark cover important content?

The watermark is placed at reduced opacity by default so the underlying content stays readable — adjust the opacity slider to your preference.

Is my file uploaded anywhere?

No. The watermark is applied entirely in your browser using pdf-lib.

Last reviewed: July 2026

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