Add a password to a PDF for free

How it works

1. 1

   Upload the PDF you want to protect.

2. 2

   Choose a password of at least 4 characters.

3. 3

   Encrypt the file on the server.

4. 4

   Download the protected PDF and share the password separately.

About the Protect PDF

Emailing a payslip, medical report or signed contract as a plain PDF means anyone who gets hold of the message can read it. Adding a password encrypts the file with AES-256, so it opens only for people who know the password. You choose the password here, our server applies the encryption, and you download the protected copy.

What you can do

• Set an open password of 4 to 128 characters.
• Encrypt every page of the document with AES-256, which current PDF readers support.
• Rename the protected file before downloading it.
• Encrypting a PDF does not change how it looks; once the password is entered, it reads exactly like the original.

When it works best

• Sending personal or financial documents by email or chat.
• Storing copies of IDs, contracts or medical records in a shared folder or cloud drive.
• Meeting a request from a bank, employer or client to send documents password-protected.
• Archiving tax returns or legal documents on a USB stick that could be lost.

Things to know

• There is no way to recover a forgotten password, so keep it somewhere safe, and share it by a different channel than the file.
• A PDF that is already encrypted is rejected; unlock it first with Unlock PDF and then protect it again.
• Pages are rebuilt during protection, so fillable form fields and links in the original may not carry over. Fill and flatten forms before protecting them.
• Files up to 25 MB are accepted. The protected copy waits on the server only for your download and is deleted automatically within about 30 minutes.
• The same password is used to open the file and to change it, so anyone who can read it can also remove the protection.

Frequently asked questions