How to Add a Watermark to a PDF: Mark Documents as Draft or Confidential

Learn how to professionally add text watermarks to PDF files. Free online PDF watermark tool that works entirely in your browser.

In the corporate and creative worlds, context is everything. If a client accidentally distributes an unfinished V1 proposal believing it is the final draft, it can cause massive confusion and financial loss.

Adding a large, semi-transparent Watermark diagonally across every page of a PDF instantly communicates the exact status of the document without obscuring the actual readable text underneath.

🛡️ Why You Should Always Watermark

The “DRAFT” Stamp: Prevents premature distribution of unfinished, unapproved work to external clients.
The “CONFIDENTIAL” Stamp: Serves as a stark, unavoidable legal reminder that the document contains highly sensitive internal data that should not be leaked.
Copyright Protection: Slapping your company name or “DO NOT COPY” across proprietary training materials deters theft.
Invoice Management: Marking paid invoices as “PAID” or “VOID” prevents accounting errors.

⚙️ How the Watermarking Engine Works

Our tool uses pdf-lib to procedurally draw text directly onto the internal coordinate grid of each individual page in the PDF.

You have absolute control over the visual presentation:

Opacity (Transparency): You can set the text from 5% (barely visible) to 80% (highly aggressive).
Dynamic Sizing: Choose between Small (36pt), Medium (60pt), or Massive (96pt).
Typography: Select classic, professional fonts like Helvetica, Times Roman, or Courier.

🔴 Data Privacy Note: Your highly confidential documents are never uploaded to our servers. The entire watermarking process happens locally inside your web browser.

🎨 Professional Watermark Settings Guide

Getting the watermark to look professional requires balancing visibility with readability.

Your Goal	Recommended Text	Ideal Opacity	Ideal Size
Internal Unfinished Work	`DRAFT`	20% - 30%	Massive (96pt)
Highly Sensitive Data	`STRICTLY CONFIDENTIAL`	30% - 40%	Medium (60pt)
Copyright Protection	`PROPERTY OF ACME CORP`	15% - 25%	Small (36pt)
Ruining a Stolen Design	`UNPAID PROOF`	50% - 60%	Massive (96pt)

🚀 Ready to stamp your documents? Don’t let your unfinished work leak out of context. Use our completely free PDF Watermark Tool to add professional, semi-transparent text watermarks instantly. No signup required!