Zro7Zro7/Lock PDF

Lock

Encrypt a PDF with a password and set permissions.

Runs entirely in your browser. Files never leave your device.

Drop PDF here or click to select

Single file

Permissions

How it works

  1. 1

    Drop the PDF

    Drag a PDF into the dropzone. It is read entirely in memory.

  2. 2

    Set a password

    Type a user password and, optionally, an owner password with permission flags.

  3. 3

    Download the locked PDF

    Click Lock to encrypt in-browser, then download the protected file.

Frequently asked questions

What encryption does Lock PDF use?

AES-256 encryption applied client-side via WebAssembly, matching the strongest option in the ISO 32000 PDF spec.

Can I restrict printing or copying?

Yes — set an owner password and disable printing, copying, editing, or annotating while still allowing the file to be opened.

Will my password be sent anywhere?

No. The password is used locally to derive the encryption key and never leaves your browser.

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