# Password-protect a PDF

Source: https://www.mergevanta.com/protect-pdf
Updated: 2026-10-22

> Protect PDF with a password online free. AES-256 encryption in your browser, optional print, copy and edit restrictions, no watermark and no sign-up.

Add a password that's needed to open your PDF, and choose whether people can print, copy or edit it. Encryption uses AES-256 and runs in your browser, so the file never leaves your device.

## How do I put a password on a PDF for free?

Add the file to Mergevanta's Protect PDF tool, type a password twice and press Protect PDF. The file is encrypted with 256-bit AES in your browser, so it never leaves your device. You can also block printing, copying or editing, and there's no watermark or sign-up.

## Key facts

- **Price:** Free
- **Watermark:** None
- **Sign-up:** Not required
- **Accepts:** .pdf
- **You get:** A password-protected .pdf
- **Processing:** In your browser — files never leave your device
- **Files stored:** Never
- **Works on:** Windows, macOS, Linux, iPhone, iPad and Android

## Why use Mergevanta

- **AES-256 encryption:** The strongest encryption in the PDF standard, supported by every current PDF reader.
- **Never uploaded:** Encryption runs in your browser, so the file and its password stay on your device.
- **Control what people do:** Allow or block printing, copying text, editing, comments and changes to the pages.
- **Password strength check:** A live hint tells you whether your password is weak, fair or strong before you lock the file.

## How to use it

1. Click Choose PDF and pick your file.
2. Type a password under Password to open the PDF, then again under Type it again.
3. Under What people can do once it's open, set Printing and switch off anything you want to block.
4. Press Protect PDF, then Download.

## Frequently asked questions

### Is my PDF uploaded?

No. Protect PDF encrypts the file in your browser, so neither the file nor the password leaves your device.

### How secure is the protection?

Files are encrypted with 256-bit AES, the strongest method in the PDF standard. The password matters most: use 12 or more characters, or a passphrase of several words.

### What's the difference between the two passwords?

The open password is needed to view the file. The permissions password lets someone change the printing, copying and editing limits; leave it empty and a long random one is used, so nobody can lift them.

### Do printing and copying limits always work?

Most PDF apps respect them, but some ignore them. Only the open password truly locks the file, so rely on it for anything sensitive.

### What if I forget the password?

It can't be recovered — not by Mergevanta or anyone else. Keep it somewhere safe, and keep an unprotected copy if you may need one.

### Can I remove the password later?

Yes. Open the file in [Unlock PDF](https://www.mergevanta.com/unlock-pdf), enter its password and save an unlocked copy.

## Related tools

- [Unlock PDF](https://www.mergevanta.com/unlock-pdf)
- [Redact PDF](https://www.mergevanta.com/redact-pdf)
- [Sign PDF](https://www.mergevanta.com/sign-pdf)