Protect PDF
Add an opening password to a PDF using AES-128 encryption in your browser. Neither the file nor the password is uploaded.
How to use this tool
- Choose a PDF that is not already protected.
- Type a password twice.
- Select Protect PDF.
- Download the result and test it in your PDF viewer.
When to use it
- Sending a document by email with a password.
- Locking a copy of a personal document.
- Adding a password before storing a file in cloud storage.
Limits
Adds an opening password using AES-128 encryption. Printing and copying are not restricted, and there is no separate owner password. A lost password cannot be recovered. Up to 50 MB. Already-protected PDFs are refused.
Privacy and file handling
Encryption happens in your browser. The file and the password are not uploaded or stored, and the password field is cleared afterwards.
Troubleshooting
If the result will not open, check you typed the password you set. Very old viewers may not support AES-128.
Frequently asked questions
Is this strong encryption?
It uses AES-128, a standard PDF encryption method. Strength depends on a long, unique password.
Can you recover a forgotten password?
No. The password is never stored and cannot be reset.
How strong is the protection?
The PDF is encrypted with AES-128, and it needs the password to open. A weak or shared password is the main risk. Keep the password safe, because it cannot be recovered.
Will it open in other PDF viewers?
The output has been checked with independent tools. Test it in your own viewer before deleting the original.
Does it use the same password for editing?
One password is used for opening. It is not a full permissions system.