Your files stay on your device

File processing runs in your browser. Documents are not uploaded to our servers. The site may download processing engines and send usage or feedback events without file contents.

How we handle your data →

Protect PDF

Add an opening password of at least 12 characters to a household PDF with AES-256 encryption, so only someone with the password can open it. Files stay in your browser.

Small converter download on first use.

One PDF, up to 20 MiB. The original file stays unchanged.

Use at least 12 characters. Keep a copy: there is no password recovery.

Try an example

Download sample

The downloaded PDF should require your chosen password and retain both pages.

What to expect

Protection uses AES-256 and sets a password to open the PDF; after opening, printing, copying and editing are not restricted. Unlocking requires the existing password; this tool does not guess passwords. Changing a PDF can invalidate digital signatures.

Processing stops after 30 seconds. Protected input can be up to 30 MiB; output is limited to 30 MiB.

The first run may download converter files and take a moment. If it fails, check your connection or try a smaller file. Cancel stops active processing; you can choose another file and retry.

Engine licenses and source code

A practical guide

Keep a personal PDF for your eyes only.

  1. Choose the PDF you want to lock and enter a password of 12 or more characters.
  2. Run Protect PDF to create an encrypted copy.
  3. Reopen the downloaded PDF with the password to confirm it works.

Try this example

Protect a scanned ID copy with the password household-vault-2026 (17 characters); the PDF should refuse to open without it and open normally with it.

Before you start: This only restricts opening the file; once someone enters the password, printing, copying and editing are not restricted.