Add Watermark to PDF PDF
Stamp DRAFT, CONFIDENTIAL or any text across every page.
Add Watermark to PDF is a free online tool that stamp DRAFT, CONFIDENTIAL or any text across every page. It runs entirely in your web browser using pdf-lib, so files are processed on your own device and never uploaded to a server. There is no sign-up, no file size limit imposed by the site, no watermark and no paid tier.
- Price
- Free — no account, no quota, no watermark
- Category
- Where it runs
- In your browser, on your device
- Files uploaded
- None
- Technology
- pdf-lib
- Settings
- 5
- Works offline
- Yes, after the first visit
About Add Watermark to PDF
Add Watermark to PDF is one of 17 pdf tools on DuckyTools, and like all of them it runs entirely inside this page. Stamp DRAFT, CONFIDENTIAL or any text across every page.
How to use it
- Choose a file, or drag it onto the drop zone.
- Set watermark text, font size and opacity and the remaining options.
- Press "Add watermark", then download what comes back.
The 5 settings
| Setting | What it does | Default |
|---|---|---|
| Watermark text | Free text. | CONFIDENTIAL |
| Font size | Range 8–200. | 60 |
| Opacity | Range 5–100%. | 15% |
| Angle | Range -90–90°. | 45° |
| Pages | Free text. | all |
Under the hood
| Runs on | pdf-lib — builds and rewrites the PDF structure |
| Controls | Watermark text, Font size, Opacity, Angle, Pages |
Questions
Can the watermark be removed by someone else?
Yes, with effort. It is drawn as real text into the page content, so a determined person with the right software can strip it. Treat it as a clear marking of intent, not as security.
What opacity should I use?
Between 10% and 20% is readable without fighting the text underneath. Above 35% starts making body copy genuinely hard to read on screen.
Why is my watermark off-center on some pages?
It is centerd using the page dimensions, so mixed portrait and landscape pages in one document will position differently. Rotating to 45° usually makes the difference less noticeable.