What encryption strength should I use?

AES-256 is the strongest and recommended for all modern use cases. AES-128 is compatible with older PDF readers. RC4-128 is a legacy option for maximum compatibility with very old software.

Can I restrict printing or copying?

Yes. You can restrict printing (full or low quality only), text and image copying, content editing, annotations, form filling, and page assembly independently.

Can the password be removed later?

Yes. Use our Unlock PDF tool to remove the password if you know it. Without the correct password, the encryption cannot be bypassed.

How long are files stored?

All uploaded and processed PDF files are automatically deleted within 5 minutes. Files are never shared with third parties.

What encryption does this tool use?

The tool supports AES-256 (recommended, strongest), AES-128, and RC4-128 encryption algorithms. AES-256 is the industry standard for secure PDF protection.

Can I restrict printing or copying from a protected PDF?

Yes. You can restrict printing entirely, allow only low-quality printing, restrict text and image copying, restrict editing, restrict annotations, restrict form filling, and restrict page assembly - all independently.

How long are files stored?

All uploaded and protected PDF files are automatically deleted within 5 minutes. Files are never shared with third parties.

Protect PDF — Add Password to PDF Free Online

Q: How do I password protect a PDF?

Upload your PDF, enter an open password, choose AES-256 encryption, then click Protect PDF. Your encrypted PDF is ready in seconds. No signup required.

Q: What is the difference between open and owner password?

The open password (user password) is required to open and view the PDF. The owner password is required to change security settings, remove the password, or override permission restrictions. You can set one or both.

How to Password Protect a PDF

1. Upload PDF

Drop or browse to upload the PDF you want to protect. Up to 50 MB.

2. Set Passwords

Enter an open password, an owner password, choose encryption strength, and restrict permissions.

3. Download

Your encrypted PDF is ready in seconds. Auto-deleted from our servers after 5 minutes.

Enterprise-Grade PDF Security

AES-256 Encryption

The same 256-bit AES encryption used by banks and governments. Virtually unbreakable with a strong password.

Dual Password System

Set an open password for viewers and a separate owner password for administrators who need to change settings.

7 Permission Controls

Independently restrict printing, copying, editing, annotations, form filling, and page assembly.

Password Strength Meter

Real-time feedback on password strength helps you choose a password that's actually secure.

Compatible with All Readers

Protected PDFs open in Adobe Acrobat, Preview, Chrome, Edge, and all standard PDF readers.

Secure & Private

Passwords are never logged. Files processed over HTTPS and deleted within 5 minutes.

Frequently Asked Questions

How do I password protect a PDF for free?

Upload your PDF, enter an open password, choose your encryption strength and permissions, then click Protect PDF. No signup required and completely free.

What is the difference between open and owner password?

The open password is required to open and view the PDF - anyone who wants to read it must enter this. The owner password is required to change permissions, remove protection, or edit the document. You can set one or both independently.

Which encryption algorithm should I choose?

AES-256 is recommended for all modern use cases - it is the strongest option and supported by all current PDF readers. Use AES-128 if you need compatibility with older software. RC4-128 is a legacy algorithm and should only be used for compatibility with very old PDF readers.

Are my passwords stored on your servers?

No. Passwords are passed directly to the encryption process and are never written to logs or stored in any database. The protected PDF is deleted from our servers within 5 minutes.

Can I recover a PDF if I forget the password?

No. AES-256 encryption is designed to be irreversible without the correct password. If you lose the open password, the PDF cannot be recovered. Always store your password in a password manager before protecting important documents.

Protect PDF with Password

Password Settings

Encryption & Permissions