# Password-protect a PDF

> How to protect a PDF with a password and AES-256 encryption in vivePDF, limit printing and copying, and keep the owner password safe.

URL: https://vivepdf.com/en/docs/password-protect-a-pdf/
Last updated: 2026-10-24

To put a password on a PDF, open **Tools › Security**, choose your file, type the **Open password** twice and click **Add password**. The protected copy is saved as a new file; your original stays as it was.

1. Open **Tools › Security**; the page opens on **Add password**. Choose the PDF, or drag it onto the window.
2. Type the **Open password** and type it again in **Confirm password**. The bar below shows how strong the password is.
3. Leave **Encryption** on **AES-256 (recommended)**.
4. To limit printing or copying, pick **Read only**, **No copying** or **Most restricted** under **Quick set** in the **Permissions** section.
5. Click **Add password**.

![Add password: Open password and Confirm password filled in, the strength bar at Strong and AES-256 selected](https://vivepdf.com/shots/en/password-1-1600.webp)

If you left the **Owner password** empty, vivePDF makes up a random owner password and shows it once in the result panel. It is the only way to change the permissions later, so copy it with the button next to it and keep it somewhere safe.

![Password added: 2 pages, a preview and the Owner password created box in the panel on the right](https://vivepdf.com/shots/en/password-2-1600.webp)

> **Don't forget the password**
>
> If you forget the open password, nobody can open the file, vivePDF included. Keep it in a password manager.

Removing a password, sealing with a certificate, watermarks and the other security tools are on the [Security](https://vivepdf.com/en/docs/security/) page.