Lock PDF with Password — Free AES-256 PDF Encryption
Password protect your PDF files with AES encryption (Server-powered)
Drop PDF file here
or click to browse
How It Works
Upload Your PDF
Select the PDF file you want to protect
Set Your Password
Enter a strong password to encrypt your PDF
Download Locked PDF
Your password-protected PDF is ready
Help & Tips
- Passwords: Add a password to restrict opening.
- Strength: Use strong, unique passwords; store safely.
- Sharing: Share passwords securely—not via plain text.
- Limits: Some viewers handle encryption differently; test outputs.
- Privacy: Server‑side; files auto‑delete. Privacy Policy.
Frequently Asked Questions
Is Lock PDF free?
Yes. 100% free, no sign-up required.
What encryption does PDFLY use to lock PDFs?
We use AES-256 encryption which is the industry standard for PDF security.
Can I restrict printing and editing too?
Yes. You can set permissions to restrict printing, editing and copying when locking your PDF.
Are my files safe when locking?
Files are uploaded to our server, encrypted and automatically deleted within 1 hour. We never store or share your files.
Can the password be recovered if I forget it?
No. If you forget your password we cannot recover it. Store your password safely before locking.
Why Use PDFLY to Lock PDFs?
Protect your PDFs with industry-standard encryption:
- AES-256 Encryption: We use the same encryption standard as banks and governments to secure your PDFs.
- Granular Permissions: Set separate permissions for printing, editing, and copying text — not just a simple password lock.
- Files Auto-Deleted: Your uploaded PDF is processed and immediately deleted from our server within 1 hour.
- No Software Installation: Encrypt PDFs from any device with a browser — no Adobe Acrobat required.
- Compatible with All PDF Readers: Locked PDFs work in Adobe Reader, Chrome, Edge, and all major PDF viewers.
Supported Formats & Limitations
| Feature | Details |
|---|---|
| Input Format | PDF (standard, unencrypted) |
| Output Format | PDF (AES-256 encrypted) |
| Encryption Standard | AES-256 (military-grade, 256-bit) |
| Maximum File Size | 200 MB per PDF |
| Password Options | User password (to open) and permissions password (to restrict actions) |
| Permission Controls | Can restrict printing, copying text, editing, and extracting content |
Common Use Cases for PDF Encryption
PDF encryption is essential for protecting sensitive information and maintaining document security:
- Financial Documents: Protect bank statements, invoices, tax returns, and financial records from unauthorized access.
- Legal & Contracts: Secure contracts, agreements, and legal documents shared with multiple parties.
- Medical Records: Encrypt patient health information and medical documents for HIPAA compliance.
- Business Confidential: Protect business plans, strategic documents, and proprietary information from competitors.
- Employee Records: Secure employee files, performance reviews, and sensitive HR documentation.