# Protect PDF

> Encrypt a PDF with a password and reader permissions.

URL: https://uttir.com/pdf-protect
Categories: pdf-tools
Privacy: Your PDF and password are encrypted locally in your browser and never uploaded.

## About

Protect PDF encrypts your document with a password using AES — the same standard used by banks and governments. Readers must enter the password to open the file, and you can restrict what they may do: printing, copying text, modifying, or filling forms.

Encryption happens on your device. The password never travels over the network, so you can safely protect sensitive documents like tax forms, medical records, or legal agreements.

## How to use

1. **Choose the PDF** — Pick the document you want to encrypt.
2. **Set the password** — Optionally add a separate owner password and permissions.
3. **Encrypt and download** — The protected PDF opens only with the password.

## FAQ

### Which encryption is used?

AES-256 by default (the strongest, ISO-recommended option) or AES-128 for maximum compatibility with very old readers. RC4 is intentionally not offered — it is broken.

### What is an owner password?

The owner password is the "admin" key: opening the file with it grants full access regardless of the permission restrictions. Leave it empty and the user password becomes the owner password too.

### Can readers still print or copy?

You choose. Permissions like printing and copying are granted or denied with checkboxes, and they apply to readers who open the file with the user password.

### Can you recover a lost password?

No — and that is a feature. AES-256 encryption cannot be bypassed, so keep the password safe. Use the Unlock PDF tool with your password to remove protection later.

## Related tools

- [Unlock PDF](https://uttir.com/pdf-unlock) — Remove the password from a protected PDF you own.
- [Sign PDF](https://uttir.com/pdf-sign) — Draw a signature on the screen and place it on any page of a PDF. Useful for contracts, forms, and approvals.
- [Flatten PDF](https://uttir.com/pdf-flatten) — Turn fillable form fields into static content.

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For the full HTML page with the live tool, visit https://uttir.com/pdf-protect.
This file is the markdown rendering at https://uttir.com/pdf-protect.md. See https://uttir.com/llms.txt for a site-wide summary.