About this tool
A watermark is a diagonal, semi-transparent stamp — "CONFIDENTIAL", "DRAFT", a company name — printed onto every page of a document so anyone looking at it (or a screenshot, printout or forwarded copy of it) can immediately tell what it is and who it came from. This tool stamps custom text onto every page of a PDF entirely in your browser: pick a file, type the text, tune the opacity, size and rotation angle, optionally tile it across the page instead of a single centered stamp, and download the result. Nothing is uploaded — the PDF is read, modified and saved using pdf-lib, a pure-JavaScript library, right on your device.
Opacity controls how much the watermark fades into the background — low values (0.1–0.2) are subtle enough not to obscure the underlying text, while higher values make a bold, hard-to-miss stamp. The rotation angle defaults to 45° (the classic diagonal watermark look) but can be set to 0° for a straight horizontal stamp or any angle in between. Turning on "repeat" adds smaller copies of the same text tiled across the corners of the page in addition to the centered one, so the mark survives even if part of the page is cropped or covered. Because the stamping happens client-side, this works offline once the page has loaded and imposes no file-size limit beyond what your browser's memory can hold.
Frequently asked questions
Can I remove a watermark I added by mistake?
Not with this tool — the watermark becomes part of the page content once saved, and this tool doesn't have an "undo" or watermark-removal function. Always keep your original, un-watermarked file so you can start over from it if needed.
Can I use an image logo instead of text?
Not currently — this tool only supports a text watermark for now. An image/logo watermark option may be added in a future update; for now, text watermarks like "DRAFT", "CONFIDENTIAL" or a company name cover the most common use cases.