catScan

Protect PDF

Protect your PDF with a password and AES encryption.

Processed on your device

  1. 1Choose the files
  2. 2Arrange and adjust
  3. 3Download

You need to sign in to use the tools. It's free.

8 free uses a month · Plus is unlimited

Add a password to your PDF so only people who know it can open it. The document is encrypted with AES-256 on your device, before it ever leaves your hands.

How to protect a PDF in 3 steps

  1. Open the PDF you want to protect.

  2. Type the password twice.

  3. Encrypt it and download the protected PDF.

Why use catScan

  • Private by design

    This tool works inside your browser: the file is processed on your device and is never uploaded or stored.

  • Free to start

    Sign in with Google and get 8 free uses per period, shared with the catScan app. 1 use = 1 downloaded file; if something fails, it doesn't count.

  • Nothing to install

    It works in any modern browser on computer, tablet or phone. To scan paper with your camera, use the Android app.

Frequently asked questions

What happens if I forget the password?

It can't be recovered: we never see or store it. Keep it in a safe place.

How secure is the encryption?

It uses AES-256, the strongest encryption in the PDF standard. Use a long password that is hard to guess.

Are my files stored?

No. This tool processes the file on your device, inside the browser: it is not uploaded to any server and nothing is stored.

Is it free?

Yes. Sign in with your Google account and you get 8 uses per period on the free plan (1 use = 1 downloaded file; if something fails, it doesn't count). catScan Plus, bought in the Android app, is unlimited on the web and in the app.

Does it work on my phone?

Yes. It works in any modern browser on Android, iPhone, Windows, Mac or Linux, with nothing to install. The catScan Android app also lets you scan documents with the camera.