Enter an open password (required to open the file)
4
Step 4
Optionally restrict printing and copying
5
Step 5
Click Protect and download your encrypted PDF
Key Benefits
🔒
Strong Encryption
Password protection uses standard PDF encryption.
⚙️
Permission Control
Restrict printing, copying, and editing separately.
🔒
Private
Encryption happens in your browser — password never sent anywhere.
💸
Free
No limits, no sign-up.
Common Use Cases
▶ Use Case 1
Protect confidential contracts before emailing
▶ Use Case 2
Lock financial reports with a password for secure sharing
▶ Use Case 3
Prevent copying of proprietary documents
▶ Use Case 4
Require authentication to open sensitive PDFs
Expert Tips
💡
Use a strong, unique password — at least 12 characters with mixed case and symbols
💡
Note your password carefully — if lost, there's no recovery
💡
Combine with a watermark for layered security
💡
Share the password separately from the document (e.g. via phone or a different channel)
Frequently Asked Questions
Is the encryption strong enough for sensitive documents? ▼
The tool uses standard PDF password encryption. For highly sensitive documents, consider additional measures like end-to-end encrypted file transfer.
What if I forget the password? ▼
There's no recovery mechanism — the password is set in your browser and never stored. Keep a secure record of it.
Can I remove the password later? ▼
Yes — use the PDF Unlock tool with the correct password to remove protection.
How Encryption Works Without a Server
pdf-lib applies AES-128 or AES-256 encryption (standard PDF security) entirely in your browser. The encryption key is derived from your password using a standard algorithm — without the password, the content is computationally infeasible to access. Your password is never transmitted, never stored, never logged. Only you ever know it.
Permission flags (print restriction, copy restriction, edit restriction) are enforced by compliant PDF viewers like Adobe Acrobat Reader. They should be viewed as a deterrent rather than an absolute barrier — some third-party viewers may not enforce them. For truly sensitive documents, the open password (which encrypts the content) provides stronger protection than permission flags alone. Use a strong, unique password of 12+ mixed characters, and store it in a password manager.
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