Protect PDFAdd password protection and encrypt PDF files
Password protect and encrypt PDF files online for free. Set a password to open the document, control printing and editing permissions, and lock it with AES encryption. Everything runs in your browser - your password is never sent anywhere.
Password Protect a PDF Document
Set a password that recipients must enter before they can open your PDF. Without the correct password, the document cannot be viewed at all. Use this when sharing confidential contracts, financial reports, or personal documents that only specific people should access.
Lock PDF From Editing and Copying
Set an owner password to control what recipients can do with your document. Allow viewing but block printing. Allow printing but prevent copying text. Block all editing while permitting form filling. Mix and match permissions to fit your needs.
Encrypt PDF Without Uploading
The encryption uses AES-256 - the same standard used by banks and governments. Unlike other tools that encrypt on their servers (which means they see your password), this tool encrypts entirely in your browser. Your password is never transmitted anywhere.
Remove the Password Later
Need to remove protection? Use Unlock PDF to decrypt after providing the correct password. Want to make form fields permanent before locking? Run Flatten PDF first so interactive elements cannot be modified even if the owner password is bypassed.
How to Password Protect a PDF
Upload Your PDF
Drag and drop your PDF or click to browse. No file size limits.
Set Password and Permissions
Enter a password. Choose which actions to allow or restrict (print, copy, edit).
Download the Protected PDF
Click Protect and download your encrypted file.
Frequently Asked Questions
How do I add a password to a PDF?
Upload your PDF, type a password, optionally set permission restrictions, and click Protect. The encrypted file downloads immediately.
What is the difference between user and owner passwords?
User password is required to open the file. Owner password controls permissions (print, copy, edit) for people who can already view it.
Can I protect a PDF from editing but allow printing?
Yes. Set an owner password and configure permissions independently - allow printing while blocking editing, copying, or form filling.
What encryption is used?
AES-256 - the strongest available for PDF. Same standard used by financial institutions and governments.
Is my password safe?
Yes. Encryption runs entirely in your browser. Your password is never sent to any server.
How do I remove the password later?
Use Unlock PDF to remove protection after entering the correct password.
Should I flatten before protecting?
If your PDF has editable form fields or annotations, yes. Flatten PDF makes them permanent so they cannot be altered even if protection is removed.
Can I lock a PDF without a password?
The owner password can restrict actions without requiring a password to open. Recipients can view freely but cannot print, copy, or edit.