Payslips, contracts, medical reports: anything you wouldn't want opened by the wrong person deserves a password before it leaves your inbox. Lock PDF encrypts your file locally with AES-256, the same standard banks and government systems rely on.
The encryption runs through your browser's built-in Web Crypto API using your chosen password. Nobody, including us, ever sees that password. It never leaves your device.
Freelancers sending invoices with bank details, HR teams distributing payslips, anyone emailing a document with a name, ID number, or financial figure attached benefits from locking it before it leaves the outbox.
Beyond just an open password, the tool also lets you separately restrict printing, text/image copying, and editing on the file — useful when you want someone to be able to read a document without being able to lift content out of it or alter it. Restricting any of these generates a second, separate owner password behind the scenes automatically, so the password you hand out only ever grants the permissions you chose, never full control.
AES-256, via the browser's native Web Crypto API. It's a widely trusted, industry-standard algorithm.
No. A file locked here needs the matching password entered through our Unlock PDF tool. It's not a standard encrypted-PDF format that generic readers understand.
No, the whole process happens locally in your browser.
There's no way to recover the file. No backdoor, no master key. That's exactly what makes the encryption worth anything in the first place.
Yes — uncheck the permissions you want restricted before locking. The password you share still opens the file; it just won't allow the restricted actions.
Not for the recipient — they still use the one password you gave them. A separate owner password is generated automatically behind the scenes to enforce the restrictions; you don't need to manage it yourself.