Loading PDF protection engine…

Protect PDF with Password Using AES-256 in Browser

Add a password to your PDF using AES-256 encryption. Everything happens in your browser – your file is never uploaded.

Drop a PDF here or click to browse PDF files only

Password (required to open the file)

Confirm password

Advanced: owner password & permissions

Owner password (optional)

The owner password controls the permissions below. If left blank, a random one is used and discarded.

Allow printing

Allow copying text

Allow editing

Permission restrictions are advisory – some viewers ignore them. Only the open password gives real protection.

⚠ Passwords cannot be recovered. If you forget it, the file cannot be opened.

This free tool adds a password to any PDF with AES-256 encryption, the same standard used by modern document systems. Everything runs inside your browser tab using qpdf compiled to WebAssembly, so your file never leaves your device. No signup, no upload, and no watermark.

What Is a Password-Protected PDF?

A password-protected PDF is a file that requires a passphrase before it can be opened. The password is used to encrypt the document's contents with AES-256, so even if the file is intercepted, it cannot be read without the correct password. This tool also lets you set an optional owner password and control permissions such as printing, copying and editing.

How to Use This PDF Protector?

Drop a PDF onto the upload area or click to browse. Type the password that will be required to open the file, then confirm it. Optionally open the Advanced section to set an owner password and adjust printing, copying and editing permissions. Click Protect & Download, and the encrypted PDF is saved directly from your browser.

Why Use Our PDF Protector?

It is free, needs no signup, and runs entirely in your browser, so your PDF is never uploaded to a server. You get real AES-256 encryption (PDF 2.0, Revision 6) through qpdf, an optional owner password, and granular permissions, all without installing software. Processing is fast, private, and works on any modern desktop or mobile browser.

Related Tools You Might Find Useful

Split PDF — separate a large PDF before protecting each part with its own password.
Merge PDF — combine several PDFs into one file and protect the result with a single password.
Watermark PDF — stamp a brand or notice on the document before encrypting it.
Image to PDF — turn scanned images into a PDF you can then password-protect.
Password Generator — create a strong passphrase for your encrypted document.
Classic Invoice — build a clean invoice PDF and protect it before sending.

Frequently Asked Questions

Is this PDF protector free?

Yes. The tool is completely free to use, with no limits on how many PDFs you encrypt and no payment or signup required.

Does it work offline?

Once the page and the qpdf WebAssembly engine have loaded, yes. Encryption runs locally, so you can keep working without a connection.

Is my data safe?

Yes. Your PDF is processed entirely in your browser tab and is never uploaded to any server, so your documents stay private on your device.

Do I need to create an account?

No account is needed. Open the page, drop your PDF, set a password and download the encrypted file right away.