Password-Protect PDF
Lock a PDF with AES-256 encryption and control permission flags.
How to password-protect pdf
- Open a PDF.
- Set a user password if you need to prevent casual opening, and an owner password to enforce permission flags.
- Choose what recipients may do with the document, then protect and download.
About this tool
PDF passwords do two different things that are easy to confuse. A user password is genuine encryption: without it, the file is ciphertext and no viewer can display it. An owner password is more like a set of preferences: it tells compliant PDF viewers not to print or copy, but it does not encrypt the content, so non-compliant tools simply ignore the flags.
For a document that genuinely must not be read by unauthorised people, set a strong user password. For a document where you want to suggest restrictions to ordinary users in normal viewers, set permission flags with an owner password. Understanding the distinction avoids false confidence in protection that looks more robust than it is.
Encryption and password entry happen locally in your browser. A password you type here is not logged or transmitted.