What is PDF Password Protect?

PDF Password Protect lets you add encryption to any PDF document. Set a password that recipients must enter before viewing the file. All encryption happens on your device — your PDF and password never leave your computer.

The tool applies standard PDF encryption (128-bit Standard Security Handler, Revision 3) using the password you set. Anyone who tries to open the file in Acrobat, Preview, Chrome, or a phone PDF viewer is prompted for the password. The original file stays on your device — encryption is applied to a copy and then offered as a download. Strong passwords with mixed characters give the best protection.

How to use

1. Upload the PDF file you want to protect
2. Enter and confirm a strong password for the document
3. Click protect to encrypt the PDF and download the password-protected version

When to use

• Emailing tax returns, payslips, or medical reports to someone over a public channel.
• Sharing draft contracts or NDAs that are not yet signed and shouldn't be viewable by random forwarders.
• Uploading sensitive documents to a cloud drive that family members or coworkers also access.

Result

Protect a tax-return.pdf with a strong password before emailing it to your accountant. The recipient will need to enter the exact password to open and view the document contents.

FAQ

What encryption strength does the tool use?

128-bit Standard Security Handler (Revision 3, RC4) user password encryption — the long-standing PDF format that every major viewer supports. A short, common password is still weak even with strong encryption because attackers guess passwords, not break the cipher. Use 12+ characters mixing case, digits, and symbols.

Will Adobe Acrobat, Preview, and mobile PDF viewers all recognise the password?

Yes. The PDF specification defines password-based encryption, so any compliant viewer will prompt for the password. This includes Acrobat, Preview on macOS, Chrome's built-in viewer, and PDF apps on iPhone and Android.

What if I forget the password I set?

There's no recovery. The tool doesn't store passwords and nobody on the internet can reset a PDF password for you. Always keep the password somewhere reliable, like a password manager. If lost, the only option is brute-force cracking, which is slow.

Can someone strip the password from the protected PDF later?

Only someone who already knows the password. The protection is genuine 128-bit PDF Standard Security encryption, not a viewing flag. Some commercial tools advertise "password removal" but they require the password to work; without it they fall back to brute force.

Does the password prevent printing or copying text too?

It can. By default the tool sets a user password that blocks the file from opening at all — the strongest form of protection. You can also restrict specific actions like printing, copying, or editing with the permissions panel, and optionally set a separate owner password that grants full access to people you trust.

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