What is Protect PDF?
Password-protect a PDF online free, without uploading it. Real AES-256 encryption, restrict printing, copying, or editing — done locally in your browser. It runs entirely in your browser, so there's no upload, no server involved, and no account required.
When to Use Protect PDF
Use Protect PDF when you need to:
- Document security
- Confidentiality
- Access control
How to Use Protect PDF
- 1.Upload the PDF you want to protect.
- 2.Set an open password (required to view the file), an owner password (required to change permissions), or both.
- 3.Toggle which permissions to restrict — printing, copying, editing, and annotating.
- 4.Download the encrypted PDF. It's AES-256 encrypted locally; the password is never sent anywhere.
Frequently Asked Questions
What's the difference between the open password and owner password?
The open password is required just to view the PDF at all. The owner password only gates changing the permissions later — a PDF can have one, the other, or both.
Is this real encryption, or just a permissions flag?
Real encryption — AES-256, the current PDF standard — is applied when you set an open password. Permission restrictions without an open password are still written into the file the same way any PDF tool declares them, but note that permissions alone are advisory: conforming readers respect them, but they're not a substitute for an open password if the content itself must stay confidential.
Does encrypting happen on my device?
Yes. The PDF is encrypted directly in your browser tab using the Web Crypto API — neither the file nor the password is ever sent anywhere.
Privacy & Security
Your protect pdf operations are 100% private:
- Nothing is uploaded to a server
- No account or sign-up required
- Works completely offline after the page loads
- All processing happens on your device
- No tracking or analytics on your files
Related Tools
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Start using Protect PDF right now — no sign-up, no install, no restrictions.
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