Add watermark to PDF
Type your text, pick a strength, and stamp every page. Nothing is uploaded.
Your files never leave your device
Drop files here
or click to choose files
How it works
This tool stamps a large diagonal text watermark across every page of your PDF — the classic CONFIDENTIAL, DRAFT, or COPY treatment, in three visibility levels. Because the text is rendered with your device's own fonts, it works in any language: Chinese, Japanese, Arabic, emoji — anything you can type — with no font files added to your document.
Watermarks are most often applied to exactly the documents you least want to upload: contracts going out for review, unpaid invoices, ID copies sent to agents. Here the stamping happens in your browser, so the document never touches a server — no retention policy, no account, no per-file fees, and you can confirm in the network tab that nothing is transmitted.
The watermark is placed behind a translucency layer at your chosen strength, angled across the page and sized to the page's diagonal, and it respects rotated pages — a landscape scan gets a correctly angled stamp too. The original file on your device is never modified; you always get a new copy.
Frequently asked questions
Can the watermark text be in Chinese or other non-Latin scripts?
Yes — any text you can type works, because the watermark is rendered with your device's fonts rather than fonts embedded in the PDF. 机密, DRAFT, or both together are all fine.
Can someone remove the watermark?
The watermark becomes part of each page's content, so casual removal is not possible in a normal PDF reader. Like all visible watermarks (including those from paid tools), it is a deterrent, not cryptographic protection.
Will the watermark cover important content?
It is stamped at low opacity behind your chosen strength, so underlying text remains readable. Use Light for dense documents and Strong when visibility matters more than subtlety.