Add Watermark to PDF

Add a watermark to a PDF for free, entirely in your browser. Type the text you want — DRAFT, CONFIDENTIAL, your name — set the size and opacity, and it's stamped diagonally across every page. The file is processed on your device and never uploaded.

Drop a PDF to start editing

Everything runs in your browser — your file is never uploaded.

100% private. Your PDF is opened, edited, and exported right here in your browser — it is never uploaded.

Need OCR, redaction, signing, or to edit text? Get the free DocLab desktop app →

Add Watermark to PDF — how it works

Open your PDF. Drag a PDF onto the page or click Choose a PDF; it loads with a thumbnail of every page.
Open the Watermark tool. Pick Watermark, type your text, and adjust the font size and opacity to taste.
Apply and download. Apply stamps the watermark onto every page, then Download saves the watermarked PDF to your device.

Your files never leave your browser

Watermarking runs on your own machine. Your PDF is read into the browser, the watermark text is drawn onto each page locally, and the result is handed back as a download — there is no upload and no server that ever sees the document. A strict Content-Security-Policy blocks the page from sending your file anywhere, and once it has loaded the tool keeps working offline. Because the web tools are open source, you can confirm the watermark is added on-device and nothing is transmitted. That makes it safe for stamping CONFIDENTIAL or DRAFT onto sensitive contracts without handing them to a third party. Read the privacy policy →

Why use DocLab

Free with no account, sign-up, or DocLab watermark of its own
Choose the text, size, and opacity
Applies to every page in one step
Files never leave your device — nothing is uploaded
No page or file-size limits
Works on Windows, Mac, Linux, ChromeOS, and mobile

Frequently asked questions

Are my files uploaded when I add a watermark?

No. The watermark is drawn onto your PDF locally in your browser; the file is never sent to a server or stored anywhere.

Is it free, and do I need an account?

Yes, it's completely free with no account or sign-up, and no DocLab branding is added — only the watermark text you choose.

Can I control where the watermark appears?

You set the text, size, and opacity, and it is tiled/centered across every page. For per-page placement or image watermarks, use the full editor or the desktop app.

Does it work offline and on mobile?

Yes. It runs in any modern browser on Windows, Mac, Linux, ChromeOS, and phones, and keeps working with no connection once the page has loaded.

Can the watermark be removed later?

It is drawn into the page content, so it is not a one-click toggle to remove. Keep your original file if you need an unmarked copy.