Unlock or Password Protect a PDF

Know the current password? Unlock the PDF. Need protection? Set an AES-256 password and document permissions, then download a new copy.

PDF processed on your device

Unlock or protect the PDF in your browser · Your original file stays unchanged

Or drop a PDF to unlock here

One PDF, up to 80 MB

Enter the current password

The tool tries only the password you provide. It never brute-forces or guesses passwords.

PDF password

Passwords are never written to the URL, localStorage, cookies, or console. Values exist temporarily in memory only while processing.

How to unlock or protect a PDF

Choose Unlock or Password protect

Unlock requires the current password; Password protect creates a new copy that requires a password to open.

Choose a mode for the result you need

Situation	Action	Check the result
You know the current password and need a copy that opens without it	Choose Unlock PDF and enter the current password	Open the download to confirm it no longer asks for a password.
Recipients should enter a password to open the PDF	Choose Password protect PDF, enter and confirm a new password	The new copy uses AES-256; open it with the password you set.
You want to limit printing, copying or editing	In Password protect mode, clear the relevant permission before processing	Check the permission flags in a PDF reader; enforcement depends on the receiving app.

Check the PDF before sharing

Open the download and compare page count, content and password prompt with the source. The tool changes protection without turning pages into images.
If you set a password, store it safely and share it separately from the file. The minimum is six characters; length and unpredictability still matter.
If the source PDF has a digital signature or interactive forms, verify them again in the output before using it.

If the file cannot be processed

Wrong or forgotten password: Enter the PDF’s correct password; the tool does not guess or recover forgotten passwords. If you do not have it, request an authorized copy.
Wrong mode selected: A plain PDF does not need Unlock. An already protected PDF must be unlocked before setting a new password.
Large or damaged file, or processing library unavailable: The limit is 80 MB per file, but available device memory also matters. Check the file in another PDF reader, keep a connection for the processing library and try again.
An older reader cannot open the protected copy: Try a PDF reader that supports AES-256 or choose a sharing method compatible with the recipient.

How the file and password are handled

The PDF and password are passed to a Worker in the same browser for QPDF WebAssembly processing; the output uses a local download link. This flow does not send the PDF or password to an KitoTool conversion API. The page still requests assets and sends general page analytics.