Add Watermark to PDF Online — Free & 100% Private
Stamp a custom text watermark across every page of a PDF — right in your browser, with full control over size and opacity.
Drag & drop a PDF here or
Why use our Watermark PDF
Free, private and fast — everything runs in your browser, so your files and text stay on your own device.
How to use Watermark PDF
Watermark PDF — complete guide
Watermarking a PDF is a quick way to mark a document as a draft, flag it confidential, or show ownership before sharing it externally — common for contracts under negotiation, internal reports, or sample work shared with a client.
Opacity is the setting that matters most for readability: a low opacity keeps the watermark subtle enough that the original content underneath stays easy to read, while a higher opacity makes it impossible to miss — useful when the goal is specifically to discourage unauthorized reuse of the document.
If you also need to number pages after watermarking, use Add Page Numbers to PDF. To trim margins once the watermark is in place, try Crop PDF.
Frequently asked questions
Can I control how visible the watermark is?
Yes. Use the opacity control to make it subtle or bold.
Does the watermark cover my content?
It is drawn semi-transparently by default so your original content stays readable underneath.
Can I watermark just certain pages?
The current tool applies the same watermark to every page in one pass.
Is my file uploaded anywhere?
No. Watermarking happens entirely inside your browser.
Does this reduce PDF quality?
No. The watermark is added directly to the PDF structure, not by re-rendering pages.
Is this tool free?
Yes, with no sign-up and no limit on how many PDFs you watermark.