PDF Password Protector
Add a password to a PDF with 256-bit AES encryption, or remove a password you already know. Powered by QPDF compiled to WebAssembly; everything runs in your browser and nothing is ever uploaded.
How it works
This tool runs QPDF, compiled to WebAssembly, entirely inside your browser. Adding a password encrypts the file with 256-bit AES; removing one decrypts it once you supply the correct password.
Your PDF and password never leave your device, there is no upload and no server. There is no way to recover a forgotten password, so keep a copy of any unprotected original.
What this does
A PDF password protector adds 256-bit AES encryption to a PDF, or removes a password you already know.
How to use it
- Open your PDF.
- Choose add or remove a password.
- Enter the password.
- Download the result.
How it works
QPDF runs in your browser via WebAssembly, so your file and password never leave your device. There is no recovery if you forget the password.
Understanding your result
The 256-bit AES encryption is genuinely strong, which cuts both ways: there is no back door and no recovery if you forget the password, so store it somewhere safe before you rely on it. Adding a password locks the file for anyone without it, while removing one still requires knowing the current password, this cannot crack a file you are locked out of.
Example
A 256-bit AES password locks a contract before sending.
Sources & methodology
Last updated .
Frequently asked questions
How strong is the protection?
Adding a password encrypts the file with 256-bit AES, the strongest encryption the PDF format supports. The same password both opens the file and removes its permission restrictions.
Can I remove a password from a PDF?
Yes, choose “Remove a password”, enter the current password, and the tool decrypts the file so it opens without one. You must know the password; this is not a cracking tool.
What if I forget the password?
There is no recovery. Encryption is one-way without the password, so always keep a copy of the unprotected original somewhere safe.
Is my PDF or password uploaded?
No. QPDF runs entirely in your browser via WebAssembly, so your file and password never leave your device.
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