Protect PDF

Password-protect a PDF with AES-256 encryption. 100% on-device.

Drop a PDF here or click to select

Your file never leaves your device · No signup · No daily limit

Up to 100 MB per file

How it works

Drop the PDF you want to protect.
Set a password (minimum 4 characters) and confirm it.
Choose what readers without the password may do: printing and copying are allowed by default, editing is off.
Encrypt and download the protected PDF. Opening it will now require the password.

What people use it for

Password-protecting a contract, invoice, or report before emailing it.
Locking down HR or medical documents so only the intended recipient can open them.
Restricting printing or copying on a document you share publicly.

Good to know

Encryption runs through the qpdf engine compiled to WebAssembly (the same engine class server-based tools use) with AES-256, entirely on your device.
A PDF that is already password-protected is rejected; unlock it first, then set the new password.
Permission restrictions (print/copy/edit) are enforced by PDF readers; a reader that ignores the spec can bypass them: the password itself, however, is real AES-256 encryption.

Frequently asked questions

How strong is the encryption?

AES-256 via qpdf: the strongest encryption the PDF standard supports, and the same level paid tools apply on their servers. Here it is applied in your browser instead.

Is my password sent anywhere?

No. Both the file and the password stay on your device; the encryption happens locally in WebAssembly, so there is nothing to transmit.

What happens if I forget the password?

There is no recovery. AES-256 cannot be bypassed. Store the password somewhere safe; without it the document cannot be opened.

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