PDFs & Documents · Add Watermark to PDF
Stamp CONFIDENTIAL or DRAFT on a PDF on your computer
Quick answer
Open Toolfox → Add Watermark to PDF, drop your PDFs, type the text (CONFIDENTIAL by default), choose position, direction, color and opacity, and click Add Watermark. The text is added as new page content, so nothing is re-encoded and bookmarks, links and form fields are kept. It runs entirely on your computer (Mac, Windows or Linux). Files are never uploaded.
How to do it
- Open Add Watermark to PDF and drop one or more PDFs.
- Type the text and choose center, top, bottom or tiled across the page.
- Set diagonal or horizontal, font size, color, opacity, and over or under the content.
- Optionally list pages like 1-3, 5, then click Add Watermark.
Options you can set
- Text
- Position
- Direction
- Font size
- Color
- Opacity
- Layer
- Pages
Good to know
- Uses the built-in Helvetica Bold font, so the text must use Latin characters (accents such as é or ü are fine; scripts like Chinese or Arabic aren't).
- The watermark is added as new page content; existing content isn't re-encoded, and bookmarks, links and form fields are kept.
- A watermark can be removed by someone with a PDF editor. Form fields and comments are drawn above it.
- Password-protected PDFs need Unlock PDF first.
Add Watermark to PDF FAQ
Can a PDF watermark be removed?
Yes, by someone with a PDF editor. It marks a document clearly but isn't a security feature.
Can I use accents or other alphabets?
Accented Latin letters such as é or ü are fine. The built-in Helvetica Bold font can't draw scripts like Chinese or Arabic.
Why can't I see the watermark on a scanned PDF?
With “Under the content”, an opaque page background such as a scan hides it. Choose “Over the content” instead.
Is Add Watermark to PDF in Toolfox free?
Yes. Add Watermark to PDF is one of 57 tools in Toolfox, a free app for Mac, Windows and Linux with no account, ads, limits or watermarks.
Does Add Watermark to PDF upload my files?
No. Toolfox processes files on your own computer and works offline; your files are never uploaded.
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Updated 2026-10-18 · Toolfox v0.2.1