Free · No signup · On your device

Protect PDF

Add an AES-256 opening password entirely on your device.

On your device · No upload, login or cloud storage. Files stay in this tab's memory until you clear them or leave. Download your result before closing the tab.

Choose a PDF

Up to 10 MB per PDF; output up to 40 MB.

New opening password

1–127 UTF-8 bytes, without control characters. Save your password before starting; we cannot recover it. This field is cleared after processing or cancellation.

Enable JavaScript to process files locally.

PDF engine licenses

Before you start

Use a strong, unique password and save it securely. Files and passwords are never uploaded. We cannot recover forgotten passwords. Use an unencrypted PDF; unlock it first if needed. Changing a signed PDF can invalidate its signature.

Processing stays in this browser, with no server fallback. We do not store documents in a database, browser history, IndexedDB or local storage. Clearing files releases this workspace's references; leaving the page ends local processing. Downloads you save remain on your device.