Protect PDF
Add bank-grade password encryption to your PDF documents.
How it works
Upload PDF
Select the document you want to protect.
Set Password
Choose a strong password for encryption.
Download
Download your password-protected PDF.
About This Tool
Password-protecting a PDF with AES-256 encryption ensures that only people who know the password can open, read, or print it. Lawyers, accountants, HR professionals, and government agencies routinely protect sensitive PDFs before distributing them, whether that is a salary slip, a contract, a legal notice, or personal identification documents.
JustConvert applies 256-bit AES encryption — the same standard used by banks and the Indian banking regulators — directly to your PDF. The protected file works in Adobe Acrobat, built-in PDF viewers on Windows and macOS, and PDF apps on Android and iOS. Your original file is never retained on our servers beyond your session.
- check_circleAES-256 bank-grade encryption
- check_circlePassword required to open the document
- check_circlePrevents unauthorized printing and copying
- check_circleInstant encryption with no software needed
- check_circleCompatible with all major PDF viewers
- check_circleFiles permanently deleted after download
What a PDF password actually protects
Encryption sounds absolute, but it helps to know its edges. A PDF open password scrambles the file so it is unreadable without the password — that part is genuinely strong, because AES-256 cannot be brute-forced with today's technology. The separate permissions layer that blocks printing, copying, and editing is enforced by the PDF reader rather than the maths, so a well-behaved viewer honours it while determined tools can bypass it. In short: the open password keeps strangers out reliably; permissions discourage casual copying but are not a vault. For anything truly sensitive, the open password is the part that matters.
Picking a password you won't lose
Because there is deliberately no recovery — JustConvert never sees or stores your password — a forgotten one means the file is gone for good. Aim for something a stranger cannot guess but you can retrieve: a passphrase of a few unrelated words is both stronger and more memorable than a short tangle of symbols. Store it in a password manager, and when you share the file send the password through a different channel than the document itself — text the password if you emailed the PDF. Never put the password in the same email as the attachment.
Protect vs Unlock vs Sign
| You want to… | Use | Effect |
|---|---|---|
| Stop strangers opening the file | Protect PDF | Password required to open |
| Remove a password you already know | Unlock PDF | Opens freely afterwards |
| Prove who approved the document | Sign PDF | Adds a visible signature |
Frequently Asked Questions
What encryption method does the PDF protection use? expand_more
JustConvert uses AES-256 (Advanced Encryption Standard with a 256-bit key), the same standard used by financial institutions and government agencies worldwide. It is computationally impossible to brute-force with current technology.
What if I forget the password I set? expand_more
There is no back door. If you forget the password, the PDF cannot be recovered. Write down your password and store it in a safe place, or use a password manager before encrypting the file.
Can the recipient open the protected PDF on any device? expand_more
Yes. The AES-256 encrypted PDF is compatible with Adobe Acrobat Reader, the built-in PDF viewer on Windows and macOS, and all standard Android and iOS PDF apps. The recipient simply needs to know the password.
Does the tool also prevent printing and copying? expand_more
Yes. The encryption also sets permission restrictions that prevent the content from being printed, copied, or edited without the password. Only authorised users with the correct password can perform those actions.
Is protecting a PDF the same as adding a digital signature? expand_more
No. Password protection restricts who can open the document. A digital signature certifies who created or approved it and detects any subsequent changes. Both serve different purposes and can be used together.