Secure PDF
Lock a PDF with a password or unlock a protected file. Encryption stays in your browser — passwords never leave your device.
Drop a PDF here or click to browse
Unlocked PDF · up to 100 MB
Lock with a password
AES-256 encryption (or legacy RC4) so recipients need a password to open the file.
Unlock when you know it
Remove protection if you have the password. We cannot crack unknown passwords.
Private by design
Passwords and files stay in your browser tab. Nothing is uploaded to our servers.
How to use Secure PDF
Choose Protect or Unlock, pick a PDF, enter the password, then download. Everything runs in your browser tab.
- 1Choose Protect to lock a PDF, or Unlock to remove a password.
- 2Select a PDF from your device (unlocked for Protect, locked for Unlock).
- 3Enter the password — confirm it when locking. Optionally set permissions.
- 4Download the protected or unlocked PDF. Nothing is uploaded.
Supported formats
Privacy
Nothing is uploaded. Passwords and PDFs stay in your browser memory and are discarded when you close or reload the page.
Frequently asked questions
No. Locking and unlocking run entirely in your browser, so passwords and files never leave your device.
No. Unlock only works if you already know the password. We cannot recover or brute-force unknown passwords.
AES-256 is the default (recommended). Choose RC4 only if you need compatibility with very old PDF readers.
Yes. Protect and unlock PDFs online for free with no account required.
The open password restricts who can view the file. An optional owner password can control printing, copying, and editing permissions.
No. Encrypting and decrypting run in your browser and download a standard PDF.