# Lock with a password

Only people with the password can open it. Protect a PDF with a password. Free to use. No sign-up. Your files never leave your device.

Use it here: https://pannapdf.app/lock-pdf/

Password protect a PDF for free. Add a password so that only people who know it can open the file. The PDF is encrypted on your own device.

Also known as: protect PDF, lock PDF, encrypt PDF, password protect PDF, add password to PDF, secure PDF.

## How it works

1. Choose the PDF you want to lock.
2. Type a password, twice.
3. Press "Lock this PDF" and save it. Nobody can open it without the password.

## Questions people ask

### What if I forget the password?

Then the PDF cannot be opened by anyone, including us. Write the password down somewhere safe.

### How strong is the lock?

It uses AES-256, the strongest locking that PDFs support.

## About Panna

Every tool runs inside the visitor's own browser. Files are never uploaded; they do not leave the phone or computer. There is no sign-up and no charge, and the site adds no watermark of its own to the files. The site can be shown in 19 languages: English, Hindi, Bengali, Marathi, Telugu, Tamil, Gujarati, Urdu, Kannada, Odia, Malayalam, Punjabi, Assamese, Maithili, Nepali, Sindhi, Konkani, Dogri, Sanskrit.

All tools: https://pannapdf.app/sitemap.md