Can I control the transparency so text behind it remains readable?

Yes! Use our opacity slider (from 10% subtle to 80% bold) to ensure the underlying document remains completely legible.

What angles are available?

45° diagonal is standard, or you can specify 0° (horizontal) or 90° (vertical).

Watermark PDF

Brand and protect your intellectual property with customizable text watermarks. Stamp "CONFIDENTIAL", "DRAFT", "DO NOT DISTRIBUTE", or custom company marks diagonally across all pages.

Drop PDF to add diagonal text watermark

Protect copyright and mark documents DRAFT or CONFIDENTIAL in-memory

Zero Server Transfer•Local RAM Sandbox

Execution Workflow

How to use Watermark PDF in 3 steps

Upload PDF Document

Drop your PDF into the tool. Processing remains completely local.

Customize Watermark Text

Type your watermark text, adjust transparency/opacity, font size, and rotation angle.

Apply & Save

Click "Watermark PDF" to stamp all pages and download the watermarked file.

Architecture Analysis

AnTPDF vs Cloud Converters

Capability	AnTPDF Client Studio	Legacy Cloud Services
Server Uploads	0% (Local WASM)	100% Uploaded to Cloud
File Size Limit	Unlimited (RAM Bound)	Capped at 15MB free
Daily Task Limits	Zero Paywalls	2 tasks per day lock
Processing Speed	Sub Second Execution	Slow cloud queues
Execution Privacy	100% In Browser RAM	Remote Cloud Server

Documentation

Frequently Asked Questions

The watermark is embedded directly into the PDF content stream. When paired with our Flatten PDF tool, it becomes permanently fused into the page graphics.

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