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PDF Watermark Adder

Protect intellectual property and confidential files by adding customizable diagonal or centered text watermarks across your PDF documents directly in your browser.

No Watermarks
Zero Server Uploads
Last updated:

PDF Watermark Adder

Drop any PDF document to stamp customized diagonal or centered watermarks directly in your browser.

Or drag & drop files hereProcessed locally (0 uploads)

Protect Documents with Custom Watermarks

Stamping "CONFIDENTIAL", "DRAFT", or "DO NOT COPY" across business proposals, intellectual property, or legal contracts ensures documents are not shared or executed prematurely.

All watermark calculations and PDF vector overlays execute locally on your computer with WebAssembly and `pdf-lib`, guaranteeing complete privacy for sensitive files.

How to Use PDF Watermark Adder (Step-by-Step)

1

Select your PDF file to load it into memory.

2

Type your watermark text, choose rotation angle (e.g. 45° diagonal), opacity, and color.

3

Click Apply Watermark and download your protected document in seconds.

Applications

Common Use Cases

  • Protect confidential business proposals and pitch decks before sending to external parties.
  • Stamp 'DRAFT', 'PRELIMINARY', or 'COPY' across contract pages to prevent premature execution.
  • Apply customized copyright and company name stamps across all PDF pages.

Privacy Guarantee

Zero Server Uploads

Unlike traditional online converters that upload your confidential documents to external cloud servers, MultiToolX executes computations in your browser runtime via HTML5 Canvas, Web Crypto, and WebAssembly.

Your data never leaves your device and cannot be viewed, stored, or harvested by anyone.

Companion Step-by-Step Guide

How to Add Confidential Watermarks and Stamps to PDF Documents

Step-by-step guide on adding custom text watermarks, draft stamps, and copyright notices across all pages of a PDF document in your browser.

Read Full Guide

FAQ

Frequently Asked Questions

Are watermarked PDFs uploaded to a server?

No. The watermark stamping executes purely inside your browser using WebAssembly and Web Crypto.