100% Local Processing

Lock & Unlock PDF

Password-protect a PDF to restrict access, or remove an existing password from a PDF you own. Entirely in your browser — no upload, no server.

Drop your PDF to lock it

Add password protection — 128-bit AES encryption in your browser

Files stay on device No upload 100% free

Related Tools

What do you want to do next?

Your edited file is ready — click any option below and it will be pre-loaded automatically.

Compress PDF
Slim it down before sending
Add Watermark
Brand it before locking
View PDF
Preview the result
Metadata Editor
Clean up metadata
100% Offline Processing

Lock & Unlock PDFs — Password Protection Without Upload

Adding a password to a PDF shouldn't mean handing that document to a web service — especially if the reason you're locking it is because it's sensitive. OfflinePDF encrypts and decrypts PDFs entirely in your browser using 128-bit AES. The password is never sent anywhere. Neither is the file.

🔒 128-bit AES Encryption
Industry-standard encryption applied locally. The same strength banks use.
🔓 Remove Passwords
Unlock a PDF you own by providing the correct password — no server needed.
🎛️ Permission Controls
Restrict printing, copying, and editing independently.
🔐 Zero Knowledge
Your password and document content stay on your device throughout.

OfflinePDF vs Typical Online Tools

FeatureOfflinePDFTypical Online Tools
Encryption happens locally✓ Yes✗ No (server-side)
Password sent to server✗ Never✓ Yes
128-bit AES✓ YesVaries
Free to use✓ YesOften limited

Frequently Asked Questions

128-bit AES with a strong password is effectively uncrackable by brute force. Use a strong passphrase.

There is no recovery mechanism — by design. Make sure to keep your password safe.

Yes. Load the locked PDF, provide the current password in the Lock tab, then set a new one.