Quick answer: Open your PDF, type your text or choose an image, adjust opacity and angle, then press Save watermarked PDF. A watermark marks a document as a draft, confidential or yours. It discourages reuse but is not copy protection.
Text watermarks and logo watermarks
- Text: CONFIDENTIAL, DRAFT, SAMPLE or a client name. Written as real text, so it stays sharp at any zoom.
- Image or logo: for branded proposals and price lists. A transparent PNG looks cleanest; width is set as a percentage of the page.
Opacity, angle and layout
| Setting | Recommendation |
|---|---|
| Opacity | 15 – 30% keeps text readable while the mark stays obvious |
| Angle | Diagonal is classic and hardest to crop out |
| Layout | Centred once, or tiled so no clean area is left for screenshots |
Choose which pages get it
Mark every page, the first page only, odd or even pages, or a range such as 1-3, 7. Sideways pages are handled correctly: the watermark is placed relative to how the page appears on screen.
How to watermark a PDF
- Add your PDF. A CONFIDENTIAL preview appears on every page.
- Set the text or logo.
- Adjust the look: size, colour, opacity, angle, layout and pages.
- Save watermarked PDF. A new copy downloads; your original is unchanged.
What a watermark does and does not do
It labels the file and makes a leaked copy obviously a leaked copy. It does not lock the file or add a password.
Not copy protection: Share sensitive files through a system with access control, and permanently remove content that must not be quoted with redaction in the PDF editor.
How the browser-based watermarker works
The file opens with PDF.js for the preview, and the watermark is written with pdf-lib, both in your browser. Text is embedded as a standard font at your opacity, and a logo is embedded once and reused, so tiling does not multiply file size. You can also add page numbers or sign in the same session.
Privacy
Your PDF is opened and changed entirely in your browser, not uploaded or stored, with no account needed. Site analytics are covered in our privacy policy.
Frequently asked questions
Is the watermark tool free?
Yes, with no signup or limit, and it adds no watermark of its own.
Is my PDF uploaded?
No. The file is read and watermarked inside your browser tab.
Can I use my logo as a watermark?
Yes. Choose a PNG or JPG; a transparent PNG gives the cleanest result.
What opacity should a watermark be?
About 15 to 30% for most documents. Tiled marks usually look better a little fainter.
Can I watermark only some pages?
Yes: all pages, first page, odd, even, or a custom range such as 1-3, 7.
Does a watermark reduce quality?
No. Existing page content is copied through unchanged; the mark is drawn on top.
Can a watermark be removed?
With enough effort, yes. It labels a document but is not copy protection; redact content that must not be seen.
Can I watermark a password-protected PDF?
Not until the password is removed.
Other PDF tools
Accuracy note: Tested with text and logo watermarks, centred and tiled, on portrait, landscape and rotated pages. Check the saved file before sending.
Content Lead, Anchor AI Tools, California, USA. Spotted an error? Email hello@anchoraitools.com and it will be checked and corrected. See our editorial standards.