Password Protect PDF

How do I password protect a PDF?

Choose your PDF, type a password twice, and press Protect PDF. The new copy asks for that password whenever someone opens it, in any PDF reader. Optionally untick permissions such as Print or Copy to limit what people can do once it is open. Keep the password safe; it cannot be recovered.

1. Press Choose a PDF.
2. Type a Password to open the PDF, then type it again.
3. Optional: untick what readers may not do, such as Print or Copy text and images.
4. Press Protect PDF, then Download.
5. Send the password to the reader separately, for example by text message if the PDF goes by email.

How strong is PDF password protection?

With AES-256 the encryption itself is very strong; in practice the password is the weak point. A long password that is not a dictionary word, such as a short sentence, is much harder to guess than a short one with symbols. The strength bar under the password box gives a quick check while you type.

Can I stop people from printing or copying a PDF?

Yes. Untick Print, Copy, Change pages, Add comments or Fill in forms. Standard PDF readers are expected to respect these limits, but other software can ignore them. They are a polite lock rather than a vault: they rely on the reader software to obey, so for truly private files, set an open password as well.

Will an old PDF reader open the protected file?

Readers from the last 15 years open AES-256 files. For very old software or some office printers, tick the AES-128 option. Both add only a few hundred bytes: our test file was 23 KB with AES-256 and 23 KB with AES-128.

How do I password protect a PDF without Acrobat?

You do not need Acrobat. This page encrypts PDFs for free in any browser on Windows, Mac, iPhone and Android. Microsoft Word can also save a document as a password-protected PDF from its export options, but only for files made in Word.