What is a PDF watermark?

A PDF watermark is a visible text or image overlay added to a document to indicate ownership, confidentiality, status (like draft), or intended use. It usually appears faintly across pages or in a fixed position and helps signal how the document should be handled without changing its original content.

Are my PDFs uploaded to a server?

No. Proton's PDF watermark tool processes your documents locally in your browser, so your files aren't uploaded, stored, or kept after processing. That means you can safely add watermarks to sensitive documents for free while keeping full control over your data.

Does a watermark protect my PDFs from AI training?

Not directly. A watermark can signal ownership or restrictions, but it doesn’t technically prevent AI systems or others from accessing the content if they obtain the file. For stronger protection, combine watermarking with private cloud storage [/drive] and controlled sharing.

Why should I watermark PDF files?

Watermarking helps clarify ownership, discourage unauthorized reuse, indicate confidentiality, and add context when sharing documents. It’s a simple way to communicate how a PDF should be used while keeping files professional and clearly attributed.

Can I watermark images too?

Yes, our image watermark tool [/drive/image-watermark] lets you add text or logo watermarks to your photos and other graphical files. It takes the same privacy-focused approach, so you can safely use it without exposing sensitive content.

Watermark PDF files online for free

Protect your PDFs with text or image watermarks for free. No sign-ups. No hidden promo. No data mining or AI training. Your sensitive documents stay safe.

Upload PDF

size up to 200 MB and 500 pages

Drag & drop your PDF here.size up to 200 MB and 500 pages

Adding a watermark does not remove or modify personal information or metadata embedded in the file. Please review and sanitize files separately before sharing.

Watermark PDF documents in seconds

Choose custom text or upload your logo

From confidential files to personal documents, text or image watermarks help show your PDFs are clearly yours, wherever you need to share them.

Easily customize your PDF watermarks

Your confidential PDFs stay on your device

Preview changes before you download

How to add watermark to PDF files

1. Upload your PDF document

Drag and drop your PDF file or select it from your device.

2. Add watermark

Use custom text or upload a logo, depending on what you need.

3. Customize it

Tweak opacity, size, angle, and more. See every change as it happens.

4. Download your watermarked PDF instantly

Your watermarked PDF is ready for download. No quality loss, no layout changes.

Tips for watermarking your PDFs

Use high-quality images so the watermark doesn't look blurry or pixelated.
Keep your watermark visible, but light enough that it doesn't get in the way of reading.
Use text watermarks when you want crisp results at any size, since they scale better than low-resolution images.
Match the watermark wording to your goal. For example, use “Confidential” or “Internal use only” for confidentiality, or your company name for branding or ownership.

Why you should watermark PDF files

Sensitive documents: Add “Confidential” or similar labels when sending contracts, reports, or internal files.
Personal paperwork: Protect IDs, certificates, or forms you upload to services with watermarks like “For verification only.”
Professional documents: Use your logo on proposals, presentations, or client deliverables to reinforce your branding.
Drafts or reviews: Label files “Draft” or “For review” so their status is clear.
Unauthorized reuse: A visible watermark establishes ownership and discourages copying or resharing without permission.
Context for sharing externally: Details like a recipient name, date, or purpose (for example, “Shared with ACME Ltd – March 2026”) clarifies how the PDF should be used.

Your data stays yours, private and secure

Your PDFs, your rules: Proton doesn't log, track, or analyze your content.
Fast and easy: No sign-ups, installs, or learning curve. Just upload, watermark, and download.
Works everywhere: Desktop, tablet, or phone — the experience stays smooth, responsive, and fully featured no matter where you use it.
Truly free: No strings attached, such as trial limits, daily caps, forced subscriptions, or hidden branding on your PDFs.

Done watermarking? Now securely store and share your PDFs

Watermarks help show ownership and discourage misuse, but they’re not enough on their own to fully protect sensitive PDFs. With Proton Drive, you can:

Share PDFs privately by email or publicly with a secure link
Control access with view or edit permissions and revoke anytime
Add password protection and expiration dates for extra security
Create or edit documents or spreadsheets online, then download as PDFs or share directly

Frequently asked questions about PDF watermarks

What is a PDF watermark?: A PDF watermark is a visible text or image overlay added to a document to indicate ownership, confidentiality, status (like draft), or intended use. It usually appears faintly across pages or in a fixed position and helps signal how the document should be handled without changing its original content.
Are my PDFs uploaded to a server?: No. Proton's PDF watermark tool processes your documents locally in your browser, so your files aren't uploaded, stored, or kept after processing. That means you can safely add watermarks to sensitive documents for free while keeping full control over your data.
Does a watermark protect my PDFs from AI training?: Not directly. A watermark can signal ownership or restrictions, but it doesn’t technically prevent AI systems or others from accessing the content if they obtain the file. For stronger protection, combine watermarking with private cloud storage and controlled sharing.
Why should I watermark PDF files?: Watermarking helps clarify ownership, discourage unauthorized reuse, indicate confidentiality, and add context when sharing documents. It’s a simple way to communicate how a PDF should be used while keeping files professional and clearly attributed.
Can I watermark images too?: Yes, our image watermark tool lets you add text or logo watermarks to your photos and other graphical files. It takes the same privacy-focused approach, so you can safely use it without exposing sensitive content.