Watermark PDF
Stamp text or a logo across pages.
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About Watermark PDF
Watermark PDF stamps custom text across every page of your PDF. Upload a file, type your watermark, then dial in the font size, opacity, and position — a diagonal 45° mark through the center, or a horizontal band along the top or bottom. Download the finished, watermarked PDF in a click.
It's completely free with no sign-up, no watermarks of ours, and no limits. Every step happens right inside your browser, so your document is processed on your own device and never uploaded to any server.
Frequently asked questions
- Is the Watermark PDF tool free?
- Yes, it's 100% free with no account, no sign-up, and no usage limits. You can watermark as many PDFs as you like.
- Is my PDF uploaded to a server?
- No. The tool runs entirely in your browser using JavaScript, so your PDF is opened, stamped, and saved locally on your own device. Nothing is ever uploaded, stored, or seen by us.
- How do I add a watermark to my PDF?
- Upload your PDF, type the watermark text, then adjust the font size, opacity, and position. Click Add watermark and download the finished file. The text is applied to every page automatically.
- Can I control how faint or bold the watermark looks?
- Yes. Use the opacity slider (0 to 100%) to make the mark subtle or prominent, and set any font size you like. Lower opacity works well for a background stamp; higher opacity and larger size create a bold overlay.
- Where can the watermark be placed on the page?
- You can choose a diagonal watermark angled 45° through the center of the page, or a horizontal watermark along the top or bottom. The chosen position is applied to every page in the PDF.
- Does it change the rest of my PDF content?
- No. The tool only draws your text on top of the existing pages using pdf-lib. The original text, images, and layout are preserved — the watermark is simply added over each page.