Add Watermark to PDF Online Free
Stamp a diagonal text watermark on every page of your PDF. Choose the text, colour, and transparency. Free, no signup, files never leave your browser.
🔒 Your file never leaves your browser. All processing is done locally.
How to Add a Watermark to a PDF
- 1
Upload your PDF
Click the upload zone or drag and drop your PDF. Your file stays on your device and is never sent to a server.
- 2
Configure the watermark
Type your watermark text (e.g. CONFIDENTIAL, DRAFT, SAMPLE). Adjust the colour and opacity to your preference.
- 3
Download the watermarked PDF
Click "Add Watermark" and download the PDF. The watermark appears diagonally across every page.
Watermarks communicate the status or confidentiality of a document at a glance — “DRAFT” warns readers the content is not final, “CONFIDENTIAL” signals restricted distribution, and “SAMPLE” marks preview copies. want2convert adds the watermark directly to every page of your PDF in the browser, with no upload or account required.
How it works: The tool uses pdf-lib to load your PDF and render a bold Helvetica text string diagonally across the centre of every page. The text is drawn at 45° with your chosen colour and opacity as a vector element — the original page content is untouched.
Choosing opacity: 20–30% is subtle — the watermark is visible but does not obscure content. 50–70% creates a prominent stamp that is harder to ignore. Try 35% as a starting point for most documents.
For stronger protection combine watermarking with a password using the Protect PDF tool.