Privatelocked on your device
Lock your PDF
Add a password so only people you trust can open it.
PDF only · max 10MB · stays on your device
Document & PDF
Password protect PDF online free
Lock a PDF with a password before you share it. Encryption runs in your browser so the file and passphrase never leave your device during the lock step.
How it works
Add one PDF (max 10MB).
Choose a password you will remember.
Lock on your device and download the protected file.
Why this tool
- On-device encryption
- Password never sent to Aniflare
- Free within file limits
- Works offline once the page is loaded
Frequently asked questions
Does PDF Lock upload my document?
No. Locking runs on your device — the PDF and password stay local.
What if I forget the password?
Aniflare cannot recover it. Only unlock with the correct password using PDF Unlock on your device.
Is password protection free?
Yes for light jobs within the 10MB limit.