pdfcosmos

Add Watermark

Stamp text or an image watermark across your PDFs: set the opacity, angle, position, and pages.

Free, fast, and privacy-first.

Add a watermark to your PDFs

or drag & drop files here

PDF files onlyup to 30 filesup to 100 MB each300 MB total

Add a watermark to a PDF: text or logo, free and private

Stamp a PDF with “Confidential”, “Draft”, your name, or your logo, to mark ownership, status, or a review copy. pdfcosmos adds the watermark entirely in your browser, so your document (and your logo image) never leave your device.

Use text or an image, then dial in the opacity, angle (45° gives the classic diagonal), and position (nine spots, or tiled to repeat across the page) and choose which pages get it. Watermark up to 30 PDFs with the same settings at once. One downloads as a PDF and several as a ZIP.

  • Text or your own logo

    Type a watermark or upload an image. A transparent PNG works best.

  • Full control of the look

    Opacity, angle, nine positions or tiled, plus font, size, and color for text.

  • Choose the pages

    Every page, first, last, or a custom range like 1-3, 5, applied per file.

  • Nothing is uploaded

    Watermarks are added in your browser. Your files and logo never leave your device.

How to add a watermark to a PDF

  1. Add your PDF(s)

    Drop one file (or up to 30) into the upload area.

  2. Set up the watermark

    Type your text or upload an image, then adjust the opacity, angle, position, and which pages get it.

  3. Download

    Click the button to stamp the watermark. One file downloads as a PDF, several as a ZIP.

Frequently asked questions

Are my PDF files uploaded to a server?
No. Watermarks are added entirely in your browser using pdf-lib. Your files (and your watermark image) never leave your device. You can confirm it in your browser's Network tab: no file data is sent.
Can I use my own logo or an image as the watermark?
Yes. Switch the watermark type to “Image” and choose a PNG or JPG (a PNG with a transparent background works best). You can set its size, opacity, angle, and position, or tile it across the page.
Which pages get the watermark?
Your choice: every page, the first page only, the last page only, or a custom range like “1-3, 5”. The range is applied to each file, so “last page” is the last page of each PDF in a batch.
Can I control how the watermark looks?
Yes. Set the opacity (how see-through it is), the rotation angle (45° gives the classic diagonal), the position (nine spots, or tiled to repeat across the page), and, for text, the font, size, and color.
Can I watermark several PDFs at once, and rotate them?
Yes. Add up to 30 PDFs and the same watermark settings apply to each. One file downloads as a PDF, two or more download together as a ZIP. Each file card also has a rotate button (↻) to turn its pages first.
Is Add Watermark free?
Yes, it's completely free to use, with no sign-up and nothing to install.