Add PDF Watermark
Online & Effortlessly
Apply custom text or image logo watermarks to your PDF pages online. Customize opacity, size, angle, and position. Clean, secure, and 100% free.
Professional PDF Watermarking for Secure Document Sharing
When distributing drafts, sensitive business strategies, confidential financial sheets, or sample digital files, protecting your copyright is crucial. Without protection, recipient parties can easily duplicate, redistribute, or plagiarize your content. Adding a clear watermark—such as a "CONFIDENTIAL" text stamp, a client-specific identifier, or your corporate logo—establishes ownership and discourages unauthorized copying.
ZenPDF provides a professional Add Watermark to PDF tool. Our editor enables you to customize and preview your watermark. You can enter text watermarks (e.g. "DRAFT", "COPYRIGHT", or your company name) with custom fonts, colors, rotations, and sizes; or upload your brand logo as an image watermark. You can adjust the opacity transparency levels so the watermark stays visible without obscuring the underlying document text.
ZenPDF respects document confidentiality. All uploads and downloads are encrypted using SSL protocols. Under our strict file retention policy, all files are permanently deleted from our servers exactly 1 hour after conversion, keeping your copyright and documents private.
How It Works in 3 Steps
Add watermarks to your PDF documents in just a few clicks.
Upload PDF
Drag and drop your PDF file into our secure watermark box or click to select the file from your local drive.
Design Watermark
Type your text watermark or upload an image logo. Customize size, rotation, opacity transparency, and page placements, then confirm.
Download Securely
Our backend flattens the watermark into the PDF layout and outputs a secured PDF. Download it instantly. Files are deleted after 1 hour.
Advanced Document Flattening Engine
Why are basic online watermarks ineffective? Many websites simply place an HTML overlay on the screen, which can be removed using simple PDF reader tools.
ZenPDF hosts a professional PDF parsing engine. When you customize your watermark, our backend processes the document stream and injects the watermark as a flattened vector layer or canvas object. This merges the watermark into the PDF architecture, preventing removal and protecting your copyrights.
Text & Image Stamps
Add typed text stamps (CONFIDENTIAL, DRAFT) or upload your brand logo file.
Opacity Control
Scale opacity from 10% to 90% to find the balance between readability and security.
Rotation & Layouts
Rotate watermarks to any angle and position them in grid arrays or standard central margins.
Strict Privacy
All operations happen in isolated server containers. Your data is deleted in 60 minutes with zero backups.
The Benefits of Choosing ZenPDF
Why thousands of users trust ZenPDF every day for their document needs.
Fast Processing
Our backend processes and outputs watermarked PDFs in less than 3 seconds.
Encrypted Transport
SSL endpoints encrypt every upload, protecting private and business documents.
No Installation
Apply text and image watermarks directly inside modern browsers on any device.
Premium Account
Upgrade to process larger files (up to 100MB) with priority processing.
Frequently Asked Questions
Ready to protect your document?
Join thousands of users who watermark documents cleanly, securely, and without installation.