Add a Watermark to a PDF
Stamp a diagonal text watermark across every page of a PDF, with a live preview. Runs entirely in your browser.
Click to upload or drag and drop
Select a PDF file
How it works
The text is drawn diagonally across the center of every page at the opacity you choose, sized from the page's shorter side, so a short word fits both portrait and landscape documents. The preview shows an approximation of the final placement and opacity.
Common uses
- Marking draft documents as "DRAFT" or "CONFIDENTIAL" before sharing
- Adding a company or copyright notice across sample documents
Size and placement, by the numbers
The text is Helvetica Bold in a fixed dark red, sized at one tenth of the page's shorter side, and turned 45° counter-clockwise. It starts at x = width ÷ 2 − textWidth ÷ 2 and y = height ÷ 2, and the rotation pivots on that starting point. On US Letter portrait (612 × 792), the size is 61.2 points. "DRAFT" is 207.3 points wide and runs from about (202, 396) up to (349, 543). "CONFIDENTIAL" is 455.6 points wide and runs from about (78, 396) to (400, 718), which still fits.
When the text is too long
Because the turn pivots on the start of the text rather than its middle, the stamp sits up and to the left of the exact page center, and text is neither wrapped nor shrunk. On a Letter landscape page (792 × 612), "CONFIDENTIAL" ends at about y = 628, above the 612-point top edge, so its last letters are cut off. A 35-character phrase such as FOR INTERNAL USE ONLY - DO NOT COPY measures about 1,258 points on Letter and is cut off at both ends. Short words such as DRAFT are the safe choice.
Options and limits
Opacity runs from 10% to 80% with a default of 30%, and the text can be up to 40 characters with a default of CONFIDENTIAL. The same stamp goes on every page. There is no color, angle, font, position or page-range setting. The download is named watermarked.pdf.
Frequently asked questions
Can I use an image as a watermark instead of text?
Not currently — this tool adds text watermarks only.
Can the watermark be removed later?
It becomes part of the page content, the same as any other PDF editing tool's watermark, so it isn't designed to be removed afterward.
Why are the ends of my watermark cut off?
The text is a single unwrapped line turned 45° from its starting point, so long text, or even a long word on a landscape page, can run past the page edge. Use a shorter word.
Can I change the watermark's color or angle?
No. The color is a fixed dark red and the angle is always 45°. Only the text and the opacity (10% to 80%) can be changed.
How long can the watermark text be?
Up to 40 characters, though far fewer fit. On a Letter portrait page, CONFIDENTIAL (12 letters) is already about 456 points long, and a 35-character phrase is about 1,258 points.