To add a watermark to a PDF, open a browser-based watermark tool, type your text (such as CONFIDENTIAL or DRAFT), set its colour, opacity, and angle with a live preview, and download the file — the watermark is stamped on every page. It runs on your device, so the PDF is never uploaded, with no sign-up. The watermark becomes part of the exported file, so keep an unmarked original.
A watermark marks a document’s status or ownership — CONFIDENTIAL, DRAFT, a company name — across every page. Here is how to add one without uploading the file, and what to keep in mind before you download.
The watermark is stamped on your device and applied to every page, auto-sized to each page.
The watermark becomes part of the exported file — it cannot be removed from the output afterwards — so always keep an unmarked copy of the original. This tool adds a text watermark; image or logo watermarks are not supported yet. A password-protected PDF must be unlocked first.
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A watermark like CONFIDENTIAL usually goes on a sensitive document — which is exactly the kind you should not upload. A browser-based watermark tool stamps the file on your device, so it is never sent to a server. You can confirm nothing is uploaded with the browser Network-tab test.