Codegrain

Protect PDF — password protect & encrypt PDF, free

Add a password and encrypt a PDF with AES right in your browser. No upload, no registration — your file and password never leave your device.

File to protect

How to use this tool

How to use this tool

  1. Add your PDF

    Drop or select the PDF you want to protect. It stays in your browser — nothing is uploaded to any server.

  2. Set a password

    Choose a password required to open the document. Optionally add a separate owner password to restrict permissions.

  3. Encrypt locally

    Click Protect. The PDF is encrypted on your device with AES — the file and password never leave your browser.

  4. Download

    Save your password-protected PDF. You will need the password to open it from now on.

Frequently asked questions

Frequently asked questions

Is my file or password uploaded to a server?

No. Encryption runs entirely in your browser via WebAssembly — the file bytes and the password never leave your device. You can verify it yourself in the browser DevTools Network tab: no file upload happens.

What kind of encryption is used?

Standard PDF password encryption (AES) applied by the qpdf engine running locally. The real protection strength depends mostly on how strong your password is — use a long, unique one.

Can you recover my PDF if I forget the password?

No. We never receive, see, or store your file or password — so a forgotten password cannot be recovered by us. Keep it somewhere safe.

Is this the same as a certified or enterprise-grade secure document?

It is standard PDF AES encryption — strong when paired with a strong password, but it is not a substitute for enterprise DRM or rights management. We do not over-promise.

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