How to Password Protect a PDF for Free (256-bit Encryption)
By PDFCrate Team · July 24, 2026
When you're sharing contracts, financial documents, medical records or any sensitive information as a PDF, adding a password is the simplest way to keep it private. Here's how to do it for free.
How to Password Protect a PDF for Free
- Go to PDFCrate Protect PDF
- Upload your PDF file
- Enter a password
- Click Protect PDF
- Download your password-protected PDF
PDFCrate encrypts your PDF with 256-bit AES encryption — the same standard used by banks and governments.
What Type of Encryption Is Used?
PDFCrate uses 256-bit AES encryption, which is:
- The strongest encryption standard available for PDFs
- Used by banks, governments and military organizations
- Virtually impossible to crack by brute force
How to Password Protect a PDF on Windows
Windows has no built-in PDF password tool. Your options:
- Free online tool — PDFCrate, no install needed
- Microsoft Word — Save as PDF with password (File → Export → Create PDF → Options → Encrypt document with password)
- Adobe Acrobat Pro — Paid, most advanced security options
How to Password Protect a PDF on Mac
- Open the PDF in Preview
- Go to File → Export as PDF
- Click Show Details
- Check Encrypt and enter a password
- Click Save
Note: Mac Preview uses 128-bit encryption. For stronger 256-bit encryption, use PDFCrate.
Tips for Choosing a Strong PDF Password
- Use at least 12 characters
- Mix uppercase, lowercase, numbers and symbols
- Avoid common words or personal information
- Use a password manager to store it safely
- Share the password via a separate channel (e.g. phone call, not the same email)
How to Remove a PDF Password
If you know the password and want to remove it, use Unlock PDF — free, no signup required.
Frequently Asked Questions
Can I password protect a PDF without Adobe Acrobat?
Yes — PDFCrate protects PDFs for free without any software or account.
What happens if I forget my PDF password?
There is no password recovery for encrypted PDFs. Store your password somewhere safe, like a password manager.
Can I restrict editing or printing without a password?
PDF permissions allow you to restrict printing and editing separately from the open password. PDFCrate's Protect PDF tool supports both.
Is the password stored on PDFCrate's servers?
No. Your password is used only to encrypt the file and is never stored. The file itself is deleted after you download it.
Can I password protect multiple PDFs at once?
Currently PDFCrate protects one PDF at a time. For bulk protection, Adobe Acrobat Pro supports batch processing.