Watermark PDF

Runs in browser PDF Editing & Annotation

Stamp CONFIDENTIAL, DRAFT, a logo or any text across your pages. Control size, colour, opacity, angle, position and which pages get it. Arabic, Hindi and Latin text are typeset with embedded fonts.

Privacy: Processed locally in your browser. Your file is not uploaded.

How are watermarks, page numbers and page sizes changed in a PDF?

A watermark, header, footer or page number is content drawn onto each page — text or an image appended to the page's content stream, or added as a stamp annotation — so it becomes part of the page like the original text, printed and copied with it. Page size and margins are separate: ISO 32000 defines them through the MediaBox and CropBox rectangles, so resizing a page or adding a margin changes those boxes and scales or offsets the existing content rather than redrawing it.

Read the guide: How to Edit a PDF Without Uploading It

The Layer option only sets the drawing order: Over draws the watermark after the page’s content, Under draws it first, so the content is drawn over it.

At the layer “Over the content”: Drawn last, on topAt the layer “Under the content”: Drawn first, underneath

  1. 1Over the contentDefaultThe watermark is drawn after the page’s content, so it crosses text and pictures at its opacity.
  2. 2The page’s own contentText and pictures; some pages also paint a full opaque background.
  3. 3Under the contentDrawn before the content: it shows through white areas, never covers text or pictures, and a full opaque background hides it.

The Layer option puts the watermark in one of the two places, never both.

How to use Watermark PDF

  1. Drop a PDF.
  2. Choose text or image and set the look.
  3. Pick position, opacity and pages.
  4. Click "Add watermark" and download.

Watermark PDF features

  • Text or image watermarks
  • Nine anchor positions, centred diagonal, or tiled
  • Size (auto or fixed), colour, opacity, angle, bold
  • Over or under the page content
  • Arabic, Hindi and Latin text with embedded fonts
  • Page selection; local processing

Watermark PDF example

Diagonal DRAFT on every page

Input:

Text: DRAFT, position: centre, angle 45°, opacity 30%, colour #d32f2f

Output:

contract-watermarked.pdf — a large translucent DRAFT across each page

Frequently asked questions about Watermark PDF

Can I put the watermark behind the text?

Yes — choose "Under the content". The mark is drawn before the page’s own content, so it shows through white areas but never covers text or pictures. Pages that paint a full opaque background will hide it.

Does it support Arabic and Hindi text?

Yes. Arabic is shaped and written right-to-left and Devanagari is rendered with proper conjuncts, using the Cairo and Noto Sans Devanagari fonts embedded in the output.

Can the watermark be removed later?

It is ordinary page content, so a determined user with a PDF editor could remove it. For tamper evidence combine it with Protect PDF permissions.

Is my PDF uploaded to a server?

No. The file is opened and processed by your browser with WebAssembly and JavaScript; nothing is sent to Mutqan Soft or anyone else. Close the tab and the file is gone. Downloading the result needs a free account — no subscription, no payment.

Can I use it on a password-protected PDF?

Yes, if you know the password: the file list asks for it once and every operation then works on the decrypted pages. The output is saved without a password unless you protect it again.

Technical notes

Text is laid out with a bidi pass (bidi-js) and script detection so Arabic runs are shaped right-to-left and Devanagari conjuncts render correctly through @cantoo/fontkit; Cairo and Noto Sans Devanagari are subset and embedded. Positions are computed in the visual frame (after /Rotate). "Under the content" moves the new content stream in front of the page’s existing streams.

References