Protect PDF
Password-protect and encrypt a PDF document
What is PDF password protection?
PDF password protection adds encryption to a PDF document so that a password is required to open or modify it. This is the standard way to secure confidential documents, restrict printing, or prevent editing of contracts and certificates.
The tool supports both user passwords (required to open the file) and owner passwords (required to change permissions). Encryption uses the AES-256 standard, which is the industry standard for PDF security.
How to use Protect PDF
Upload your PDF
Click the upload area or drag and drop the PDF you want to protect.
Set a password
Enter a strong password. Optionally set an owner password and configure permissions such as print restriction or edit restriction.
Click Protect PDF
The PDF is encrypted in your browser with AES-256 encryption.
Download the protected PDF
Click Download to save the encrypted PDF. Keep your password safe — it cannot be recovered if lost.
Frequently asked questions
What encryption does the tool use?
The tool uses AES-256 bit encryption, which is the current industry standard for PDF security and is approved for protecting sensitive documents.
What is the difference between a user password and an owner password?
A user password is required to open the document. An owner password controls permissions — printing, copying, and editing. Anyone with the owner password can change these restrictions.
Can a protected PDF be unlocked?
If you know the password, yes — use the Unlock PDF tool on this site. Without the password, recovering the content requires specialized software and can be computationally intensive.
Is my PDF uploaded to a server for protection?
No. Encryption is applied entirely in your browser. Your file and password are never transmitted over the network.