Protect a PDF with a password online
Add a password to a PDF (AES-256 encryption) directly in your browser, without uploading the file to a server.
or click to select it
Add a password to a PDF directly in your browser: nobody will be able to open it without knowing it. Choose the password, confirm it, and download the encrypted PDF.
Encrypts the PDF's content with AES-256, the currently recommended algorithm for document encryption, so the file can only be opened by entering the chosen password.
Use cases
- Protect a document with sensitive information before emailing it.
- Add an extra layer of security to a contract or invoice.
- Restrict access to a PDF you're going to share with several people.
How it works
- 1
Upload your PDF
Drop the file in or select it from your device.
- 2
Choose a password
Type it twice to confirm it.
- 3
Download the protected PDF
Nobody will be able to open it without the password.
Technical details
Uses pdf-lib's native encryption feature (the browser's Web Crypto API for secure random key generation). The same password is used to open and edit the document; this tool doesn't distinguish granular printing or copying permissions.
Frequently asked questions
What happens if I forget the password?
There's no way to recover or remove the password without knowing it — keep it somewhere safe, like a password manager.
What kind of encryption does it use?
AES-256, the strongest algorithm currently recommended by the PDF standard (ISO 32000-2) for protecting documents.