PDF Password Protector
Add a password to a PDF, right in your browser.
Free tool to password-protect a PDF. Upload a file, set a password, and download an encrypted copy that requires the password to open. Everything runs in your browser — your PDF is never uploaded.
How to use the PDF Password Protector
- 01Drop your PDF in, or click to choose it.
- 02Enter a password (and optionally a separate owner password).
- 03Click Protect PDF — the encrypted PDF downloads instantly.
Frequently asked questions
Is my PDF uploaded to a server?
No. Encryption happens entirely in your browser with the pdf-lib library, so your document and your password never leave your device.
What's the difference between the user and owner password?
The user password is needed to open and read the PDF. The owner password controls permissions like printing and copying. If you leave the owner password blank, it's set to the same value as the user password.
Can this be undone?
Yes — keep your password and use the Unlock PDF tool to produce a decrypted copy. Without the password the file cannot be opened, so store it somewhere safe.