Password protect a PDF

Lock a PDF so only people with the password can open it. Encryption uses AES-256 and happens on your device, so the file and password never travel anywhere.

Uploaded to servers0 B
Processed locally0 B

Uses AES-256 encryption. Keep the password safe: there is no way to recover it.

Why your files stay on your device

Nothing is uploaded

Most online PDF sites send your file to their servers. PDFMoss does the work inside your browser, so there is nothing to intercept, store or leak.

No limits on uses

There are no daily caps because there are no servers doing the work. Use any tool as often as you like.

Works on your phone

Every tool works on iPhone and Android: pick photos from your gallery and sign with your finger.

Original quality, works offline

Pages and images keep their quality, and once you install the app the tools work without an internet connection.

How to password protect a PDF

  1. Drop a PDF on the page or click to choose it.
  2. Type the password twice; tick the box to also block printing and copying.
  3. Click Protect and download the encrypted PDF.

Frequently asked questions

How strong is the encryption?

It uses AES-256, the strongest encryption the PDF format supports, read by Adobe Acrobat, Preview, Chrome and other modern readers.

What if I forget the password?

There is no way to recover it, so store it somewhere safe before you share the file.

Is my password sent anywhere?

No. The PDF is encrypted in your browser; neither the file nor the password is uploaded.

Are my files uploaded to a server?

No. PDFMoss processes files inside your browser. The counter at the top of the page shows 0 B uploaded because nothing is sent.

Is PDFMoss free?

Yes. Every tool is free to use with no sign-up and no watermark on your files.

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