Vector Layers
We don't 'paint' over the PDF. We add a new transparent layer on top of existing content. This ensures original text remains selectable and searchable, while the watermark remains visible.
Original text remains legible and copiable.
Watermark PDF Free: Ownership Stamp
Protect your work. Add logos, signatures, or 'Confidential' text with full opacity control.
100% Secure
Free Design
Transparency
Mobile Friendly
📋 Setup
How to Add Watermark to PDF?
Customize and protect your documents in 3 steps.
Upload Document
Drag the PDF you want to mark.
Design Mark
Type text or upload your logo. Adjust size, rotation, and transparency.
Stamp & Download
We apply the mark to all pages instantly.
Professional Digital Stamping
Design tools to make your brand look perfect.
Logos & Images
Upload your logo (PNG, JPG) and place it anywhere. Supports transparency.
Opacity Control
Make the mark subtle to not cover text, or very visible for maximum security.
Auto Mosaic
Want maximum protection? Repeat your mark across the entire page automatically.
Dune Safe™
Processing is local. Your designs and documents are stored on no server.
Exact Position
Use the 9-point grid or precise coordinates to place the stamp.
Rich Typography
Choose from serif, sans-serif, or monospace font families for text.
Visual and Technical Protection
How digital watermarking works.
Local Privacy (WASM)
For movie scripts, engineering blueprints, or confidential drafts, security is vital. The stamping process is done in your browser via WebAssembly, never uploading the file to the cloud.
Ideal for sensitive intellectual property.
Copy Deterrence
A semi-transparent watermark crossing the page makes it very difficult to use the document without authorization, as removing it with Photoshop requires a lot of time and manual effort.
Effective protection against unauthorized use.
When to Use Watermarks?
Drafts and Preliminary Versions
Prevent a client from using a final design without paying by clearly marking it as 'DRAFT' or 'SAMPLE' in semi-transparent red letters.
Internal Documents
Label manuals or price lists as 'INTERNAL USE' or 'CONFIDENTIAL' to remind employees not to share them externally.
Copyright of Works
If you sell ebooks or PDF guides, place your name or website in the footer or background to ensure authorship if the file is shared illegally.
Format Comparison
Choose the right format for your use case
| Type | Customization | Ideal Use | ||
|---|---|---|---|---|
| Text | Font, Color, Size | ✅ | N/A | Drafts, 'Uncontrolled Copy' |
| Image | Logo PNG/JPG | ✅ | N/A | Corporate Branding |
| Mosaic | 45° Repeat | ✅ | High Security | Valuable Intellectual Property |
Watermark FAQs
We resolve doubts about design and protection.
Can I use an image with transparent background (PNG)?
Yes, it is ideal. If you upload a PNG with transparency, it will be respected perfectly when stamped on the PDF, achieving a professional and integrated finish.
How do I put the mark behind the text?
By default, the mark is placed on a top layer with transparency. To make it look like it's 'behind', simply reduce opacity to 20-30%.
Can the watermark be removed later?
It is difficult. Once the PDF is saved, the image merges with the document. Advanced editing tools would be needed to try to erase it without damaging the text.
Can I put different marks on each page?
Currently the tool applies the same mark to the entire document to ensure consistency. We are working on dynamic marks for the future.
Does it affect file size?
Minimally. If using text, impact is negligible. If using a high-res image, PDF will grow slightly, but we optimize the image before inserting it.
Is it legal to watermark another person's PDF?
You should only mark documents of which you are the author or have rights. Marking official or third-party documents could violate their integrity.
Can I rotate text diagonally?
Yes, you have a rotation control. The standard for 'Confidential' marks is usually 45 degrees diagonally across the page.
Does it work if PDF is protected?
We cannot edit an encrypted file. You must unlock it first with our Unlock PDF tool before adding the mark.