Lock PDF
Encrypt a PDF so it can only be opened with your password.
Runs in your browser. Files aren’t uploaded.
Choose a PDF
Drop a PDF here, or choose from your device.
How to use Lock PDF
- 1Choose the PDF you want to protect.
- 2Enter a password twice.
- 3Select Protect PDF and download the encrypted copy.
Good to know
- Files are encrypted with AES-256 (the PDF 2.0 standard security handler). Adobe Acrobat, Chrome, Edge, Firefox, macOS Preview and current PDF apps can open them with the password.
- Very old PDF readers that predate AES-256 support may not be able to open the file.
- Your password isn’t stored or sent anywhere, so it can’t be recovered if you forget it.
- To change the password of an already protected PDF, unlock it first.
Supported files
- Input
- PDF, up to 150 MB
- Output
- A password-protected PDF (AES-256)
Processing happens on your device, so very large files depend on its memory. Free, with no sign-up or watermark.
What people use it for
- Protect payslips, bank statements or ID copies before emailing
- Share confidential reports
- Store personal documents more safely
Lock PDF questions
Something else? Visit support
Files are encrypted with AES-256, the strongest password protection in the PDF standard. A long, unique password matters as much as the encryption.
It can’t be recovered. The password isn’t stored or sent anywhere, so keep it somewhere safe.
Adobe Acrobat, Chrome, Edge, Firefox, macOS Preview and current PDF apps open it with the password. Very old readers without AES-256 support may not.