How do I add a watermark to a PDF?
Drop the PDF into the box above and type your text. Set the color, size, opacity and angle while the preview of page one updates, choose all pages or a range, then click “Add watermark”. You get a new, marked PDF to download, and your original file stays untouched.
The text is drawn onto each chosen page using your settings. Everything else on the page stays where it was, so the original words and images are still there beneath the mark. The preview shows only the first page, which is usually enough to judge the look, but check the saved file if later pages are very different, such as full-page photos.
Tip: Keep opacity low for long documents. A faint diagonal mark is noticed at a glance but doesn’t tire the reader’s eyes.
How do I watermark an ID copy so it can’t be misused?
When a landlord, employer or agency asks for a copy of your driver’s license or passport, a watermark limits what that copy can be used for. Stamp a short line stating the purpose, the recipient and the date, for example “Copy for rental application, Oak St, 12 Oct”. A copy with a clear purpose written across it is much harder to reuse for anything else.
If your ID is a photo rather than a PDF, turn it into one first with the JPG to PDF tool, then stamp it here. For a long line like that, lower the text size and use the 35 or 45 degree angle so it crosses the image instead of running off the page. A logo can’t be used as a watermark here, since the tool works with text.
How do I make a watermark readable without hiding the page?
- Keep it short. One to three words fit comfortably. A long sentence may run past the page edge unless you reduce the size.
- Test the contrast. Gray on a white page suits most documents. On dark or photo-heavy pages, try a lighter color or higher opacity.
- Go diagonal for text-heavy pages. At 35 or 45 degrees, the mark crosses the page without sitting on top of a single line.
- Skip the cover if you like. Enter a range such as page two onward when the cover should stay clean.
- Mark copies by recipient. Run the tool once per person with their name as the text, so each copy can be traced back.
Is it safe to watermark a PDF online?
Yes. You open the tool online, but the watermarking runs on your own phone or computer. The browser reads the PDF, draws the text and hands you the result, and at no point is the document sent to a server. That is exactly what you want for a contract, an internal report or an ID copy.
You can verify it: open your browser’s network tab and stamp a file. No file data leaves your device, because the watermark is drawn right in your browser. Nothing to install, and it works the same on a phone or a laptop.