Add Watermark to PDF

A watermark tells every reader what a document is — a draft, a confidential copy, a sample — or who it belongs to. This tool stamps text or your logo onto the pages of one or many PDFs, centred, in a corner or tiled across the page, at the angle, size, colour and transparency you choose. The pages themselves are not re-rendered, so text stays selectable and sharp, and nothing is uploaded: the PDF is edited inside your browser.

How to use this tool

1. Choose one or more PDF files.
2. Pick Text and type the words, or pick Image and choose a PNG, JPG or WebP logo.
3. Set the position, rotation, opacity and size (text size in points, image width as a share of the page).
4. Limit it to certain pages if needed, and choose whether it sits over or under the content.
5. Download the watermarked PDF.

Formula

Each watermark is placed by its centre: the page centre, a corner inset by the edge distance, or a staggered grid for tiling. The rotated box is |w·cos θ| + |h·sin θ| wide and |w·sin θ| + |h·cos θ| tall, which keeps corner watermarks inside the page at any angle.

Opacity is stored as a transparency setting in the PDF, so the page content shows through. Pages that are displayed rotated (for example scanned landscape pages) are detected, so the watermark is upright as you see the page.

Example

Stamping CONFIDENTIAL at 60 pt, 45°, 25% opacity in red on a 12-page A4 report puts one large diagonal word in the middle of all 12 pages; the file grows by only a few kilobytes because the text is drawn with a built-in PDF font. Typing 2-5 in Pages marks only pages 2 to 5.