To password-protect a PDF, open Protect PDF, drop your file, set a password, and download the encrypted copy. The encryption runs entirely in your browser, so neither your document nor your password is ever sent to a server — a real advantage over cloud tools that receive both.
Why protect a PDF locally matters
Password-protecting a PDF is exactly the kind of task where uploading is self-defeating: the whole point is confidentiality, yet most online tools send your sensitive file (and the password) to their servers. Doing it on your own device keeps the secret a secret.
How to add a password
- Open Protect PDF and drop your PDF.
- Type the password you want to require.
- Click Protect and download the encrypted PDF — any reader will now prompt for the password.
Removing a password you know
Need to drop the password from a PDF you can already open? Use Unlock PDF with the current password to save an unprotected copy. (You must know the password — this isn't a way to bypass protection you don't have rights to.)
Related: mark documents as confidential
To visibly flag a document without encryption, add a stamp with Watermark PDF — "CONFIDENTIAL" or "DRAFT" across every page, also done in your browser.