meldpdf

Password protect a PDF — privately

Add a password to a sensitive PDF, or remove one you already know. It uses strong 256-bit AES encryption and runs in your browser — your file is never uploaded.

How to add a password

  1. Open the Protect / Unlock tool and add your PDF.
  2. Choose “Add a password” and type the password you want.
  3. Apply. The engine encrypts the file on your device (it downloads once on first use).
  4. Download the protected PDF and store the password somewhere safe.

How to remove a password you know

Switch the action to “Remove a password”, enter the PDF's current password, and download an unlocked copy. This only works when you know the password.

🔒 We can't crack locked PDFs — removing a password requires the correct one.

This is deliberate. A tool that bypassed encryption would put everyone's protected documents at risk. meldpdf only helps you protect your own files, or unlock ones you already have the password for.

Choosing a good password

256-bit AES is only as strong as the password behind it. Use a long, unique passphrase, and share it with the recipient through a separate channel (not in the same email as the PDF).

Frequently asked questions

Is my PDF uploaded?

No — encryption runs in your browser. The engine downloads once; your file never leaves your device. See our privacy policy.

Can you remove a password I don't know?

No. That would be cracking encryption, which we don't do. You need the current password.

How strong is it?

256-bit AES, the strongest standard PDF encryption.