Password Protect a PDF

Acrobat Pro, Word and some printer apps can add a PDF password, but many people do not have them at hand, and free online services ask you to upload the very file you want to keep private. This page does the same job in the browser on any computer or phone: Windows, Mac, Linux, Chromebook, Android or iPhone.

Common uses: HR sending salary slips or Form 16 to each employee, a CA sending a return or balance sheet to a client, a patient sharing lab reports, a landlord and tenant sharing a signed agreement, and anyone emailing a scanned PAN, passport or Aadhaar. Many banks and fund houses already lock statements with a password based on your name and date of birth; you can follow the same idea with a password the receiver already knows, such as a date of birth, but a longer password of 10 or more mixed characters is much harder to guess.

To print a hard-to-copy handout, tick Stop copying, and to share a final version that should not be changed, tick Stop editing. If the file is too large for email after protecting, compress it first with Compress PDF and then add the password, because a protected PDF cannot be compressed further without the password.

How the receiver opens it: on a computer, double-click the file or open it in Chrome, Edge or Acrobat Reader, and a box asks for the password. On iPhone and iPad, tap the attachment in Mail or open it from Files and type the password. On Android, open it in Google Drive, Files or any PDF app. Nothing has to be installed. If you ticked restrictions, the file still opens with the password, and print or copy buttons are greyed out in apps that follow the settings.

Choosing a good password matters more than the encryption itself. AES-256 cannot be broken in practice, so attackers try likely passwords instead. A short word, a phone number or a date of birth on its own can be guessed quickly by software. Four random words, or 10 or more mixed letters, numbers and symbols, are far safer. Never send the password in the same email as the file, and change your approach if the file is very sensitive: share the password in person or on a call.

Everything happens in this tab. The PDF and the password are never uploaded or stored, and the protected copy is saved straight to your device.

Write the password down. It cannot be recovered. A PDF that already has a password needs it removed first with Unlock PDF.