Password Protect PDF

Password protect PDF files in your browser: set a password, and the file is encrypted on your device before you download it. It uses AES-256, and neither the file nor the password is uploaded.

01 Protection no file

Drop a PDF to protect

Set a password and download an AES-256 encrypted copy.

AES-256password required to open

RunAES-256 encryption

02 Output Idle preview

A padlock drops onto a document and clasps shut as a progress bar fills to 100 percent, then a Download button appears. Everything runs in your browser; the file is never uploaded. Your protected file appears here after you run it.

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phase preview
add a PDF to protect

Encrypted locally — never uploaded

How to password protect a PDF

Add your PDF. Drop it in the tool, or click to choose it.
Set a password. At least 12 characters, with upper and lower case, a number and a symbol.
Encrypt and download. Apply AES-256 protection and download the locked PDF.

Password protect PDF FAQ

Is my file or password uploaded?

No. Encryption runs entirely in your browser using qpdf compiled to WebAssembly, and nothing is stored. You can check by opening your browser’s Network tab, or by going offline before you press Protect.

How strong is the encryption?

AES-256, the standard PDF password encryption. Without the password the file can’t be opened at all.

Can I block printing or copying only?

No. This tool sets a password to open the file, which is the strongest restriction. It doesn’t set separate print or copy permissions.

What if I forget the password?

There is no back door, so the file can’t be opened. Keep the password somewhere safe. If you know it, you can remove it later with Unlock PDF.