How long can the watermark text be?

Up to 40 characters, and it shrinks to fit across the page diagonal. Letters outside the basic Latin set become “?”.

Which image formats work for a logo watermark?

PNG and JPEG. In the centre the logo covers about half the page width, faintly; in the corner it is small and nearly solid.

What do the strength options mean?

Light grey is about 12% opacity, grey about 25%, and red a red tone at about 22%.

Tools ›

Add a watermark to a PDF

Stamp DRAFT, CONFIDENTIAL or any text diagonally across every page, or place your logo faintly in the centre or small in the corner.

Open Watermark →Free · no sign-up · your file never leaves your browser

When you'd use it

Sending a report draft to colleagues so nobody mistakes it for the final version.
Sharing a portfolio or price list with your company logo faintly on every page.
Marking a copy of your ID as SAMPLE before sending it with an application.

Just say what you need

There are no menus to learn. Drop your file on pdfagents.ai and type it the way you would say it:

“stamp DRAFT across every page”
“add my logo to every page”
“mark it confidential in red”

How it works

Drop the PDF.
Say the text and pick the strength.
Download the watermarked PDF.

Questions

How long can the watermark text be?: Up to 40 characters, and it shrinks to fit across the page diagonal. Letters outside the basic Latin set become “?”.
Which image formats work for a logo watermark?: PNG and JPEG. In the centre the logo covers about half the page width, faintly; in the corner it is small and nearly solid.
What do the strength options mean?: Light grey is about 12% opacity, grey about 25%, and red a red tone at about 22%.

Private, and it keeps going

Your document is opened and saved on your own device, never uploaded. When the result is ready, type the next request (rotate, compress, add a password) and it applies to the result.

Watermark, right now

The PDF with a text watermark across every page.

Open Watermark →

Doing this often? The free Mac app runs this agent on whole folders, offline, with no page limit. See the Mac app →