Add Watermark to PDF

Stamp a text watermark like "CONFIDENTIAL" or "DRAFT" across every page. Runs entirely in your browser.

Watermark your PDF

Upload a PDF, choose your watermark text and style, then stamp it across every page.

Drag & drop a PDF file here, or click to browse
Choose one PDF to add a watermark to.

    Watermarked file ready

    Watermarked PDF
    0 pages
    Your files are processed locally in this browser tab using JavaScript. They are never uploaded to Calcooo or any server.

    How to use this tool

    1. Drag and drop your PDF file into the box above, or click to browse and select it.
    2. Type the watermark text you want and adjust the font size, angle, opacity and color to taste.
    3. Press Add watermark to stamp the text across every page of the PDF.
    4. Click Download watermarked.pdf to save the result to your device.

    FAQ

    Frequently asked questions

    Is my PDF uploaded anywhere when I add a watermark?

    No. The watermark is stamped entirely inside your browser using JavaScript (pdf-lib). Your file never leaves your device.

    Can I control how see-through the watermark is?

    Yes. Use the opacity slider to set how see-through the watermark is — lower values make it more subtle.

    Can I angle the watermark diagonally?

    Yes. The angle field defaults to 45° for a classic diagonal stamp, but accepts any value from -90 to 90 degrees.

    Will the watermark appear on every page?

    Yes. The watermark text is applied to every page in the document, using the same size, angle, opacity and color.