Require a password before opening
Create a protected copy when a PDF should not open casually without the password you provide.
PDF
Drop a PDF file hereAbout Protect PDF
Protect PDF adds an open password to a PDF so the password is required before the document can be viewed. Set a password and create an AES-256 protected copy.
Common use cases
Share a document through a separate-password workflow
Send the protected PDF through one channel and communicate the password separately according to your own security process.
Protect an exported working copy
Keep an original separately and create a password-protected derivative for distribution.
How it works
1
Zavilo reads the unencrypted source PDF in the browser.
2
The browser PDF encryption engine creates a new AES-256 protected document using the password you enter.
3
The protected file is downloaded as a new copy; the original file remains unchanged.
Privacy & file handling
Password protection is created locally
The PDF and chosen password are handled by the online encryption workflow rather than being sent to Zavilo for server-side encryption.
Limitations and important notes
- A forgotten password can make the protected file inaccessible, so store it securely.
- Password encryption controls document access but does not prevent every possible form of copying once an authorized user opens the file.
- This tool currently creates AES-256 protected output rather than offering multiple encryption strengths.
PDF password protection in context
| Feature | Provides | Does not guarantee |
|---|---|---|
| Open password | Requires a password before normal opening | Protection after an authorized user has opened the document |
| AES-256 encryption | Strong modern PDF encryption | Recovery if you lose the password |
| Digital signature | Not the same feature | Use a signature workflow when authenticity/integrity is the goal |
How to use Protect PDF
- 1
Choose the PDF you want to protect.
- 2
Enter and confirm a password.
- 3
Check the password strength and click Protect PDF.
- 4
Download the password-protected PDF.
Tips for better results
- Use a long, unique password that is difficult to guess.
- Keep a secure copy of the password because a lost password may prevent access to the document.
- For an already protected PDF, remove the current password before setting a new one.
Frequently asked questions
What encryption is used?
The protected PDF is created with AES-256 encryption.
Can I change the password of an already protected PDF?
Remove the existing password first, then protect the unlocked PDF with a new password.
Will the PDF ask for the password when opened?
Yes. Compatible PDF readers will request the password before opening the protected document.