Encrypt your PDF with a strong password to prevent unauthorized access.
Select PDF to Protect
or drop your file here
Protecting a sensitive document by uploading it to an unknown cloud server defeats the purpose of security. PDFUp's Protect tool uses AES-256 encryption directly inside your web browser. Your confidential file never leaves your computer, ensuring military-grade security without the risk of interception.
Choose the document you want to secure from your local device.
Enter a strong password. This password will be required for anyone attempting to open or read the PDF.
Click encrypt. The browser will instantly secure your file using 256-bit encryption without uploading it to any server.
We use the latest PDF 2.0 encryption standards, making your document mathematically impossible to crack without the password.
Because the cryptography happens locally using WebAssembly, your file is never transmitted over the internet.
No! The encryption happens entirely in your web browser. We never see your document, your password, or your data.
Because we use strong AES-256 encryption and do not store copies of your files, the document cannot be recovered if you lose the password. Please keep it safe.
Adding a password to a PDF is the best way to secure a document you're about to email or store on a shared drive. But if you use an online tool to apply that password, you're usually forced to upload the unencrypted file to their servers first. Sending an unsecured financial statement, legal contract, or personal record across the internet completely defeats the purpose of trying to protect it in the first place.
Our tool solves this by running military-grade AES-256 encryption directly inside your web browser. When you select a document and type in a password, the mathematics to lock the file happen entirely on your computer's own processor. Your file is never uploaded, and your password is never transmitted. You are the only person who holds the key.
This localized process also means there's no waiting. You don't have to upload a heavy file, wait in a server queue, and then download the protected version. The encryption happens instantly, giving you a perfectly secure file that you can safely share with anyone.