Password Protect PDF
Add a password to your PDF to protect its content. 100% in your browser.
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Monthly users
200,000+
PDFs compressed
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Satisfaction
How protecting PDF works with puduPdf
puduPdf protects your PDF using RC4 128-bit encryption with user and owner passwords. Both passwords are set to the same value you enter. Encryption is performed entirely in your browser — your password is never transmitted to any server.
How to password protect a PDF for free
- 1
Upload your PDF
Drag or select the PDF file you want to protect with a password.
- 2
Enter the password
Type a secure password and confirm it by entering it a second time. Minimum 4 characters.
- 3
Download the protected PDF
Click 'Protect PDF' and download your encrypted document that will require a password to open.
Key features
- RC4 128-bit encryption with user and owner passwords
- Your password never leaves your device — 100% local encryption in your browser
- Password confirmation with minimum 4-character validation for added security
- Compatible with all PDF readers that support password-protected documents
Frequently Asked Questions about Protecting PDF
Everything you need to know about password protecting PDFs
What type of protection is applied?
puduPdf applies RC4 128-bit encryption with user and owner passwords. A password is set that is required to open the document. Anyone attempting to open the PDF will need to enter the correct password.
Is it secure? Is the password sent to any server?
It is completely secure. Encryption is performed 100% in your browser. Your password is never transmitted to any server or leaves your device. Unlike online tools that process in the cloud, puduPdf ensures your password and PDF remain completely private.
Can I remove the password later?
To remove the password you will need the original unprotected file. We recommend keeping a copy of your unencrypted PDF as a backup. Once protection is applied, the PDF is encrypted and requires the password for any access.