Free PDF Merger is a free PDF merger software to merge multiple PDF files into one big PDF file.

Encrypt PDF files with password:

Free PDF Merger may be known as a PDF merging software, but it can also encrypt a PDF file with password and set PDF restrictions. The trick is adding only one PDF file into the merging list and setting encryption information in the Settings tab.

After downloading and installing Free PDF Merger, select START -> Programs -> Weeny Free PDF Merger -> Weeny Free PDF Merger to run.

1. Click on Add PDFs button. Browse windows will be opened, choose a local PDF file (*.pdf) and click Open. The trick is adding one PDF file only so this software will not merge the PDF file with other files.

2. Click Settings button on the bottom to show PDF settings, click Security Settings on the left, select Enabled Password Encryption checkbox. Enter passwords to open document or passwords to edit document, select PDF restriction options, choose encryption algorithm from 40-bit, 128-bit AES and 128-bit ARC-FOUR.

The password to open document is called user password. The user password encrypts the file and requires password cracking to defeat, with difficulty depending on password strength and encryption method. It is potentially very secure. The password to edit document is called owner password. The owner password does not encrypt the file, and instead relies on client software to respect these restrictions, and is not secure. Click here for more information about PDF user password and owner password.

3. Click on Merge Now! button. Free PDF Merger will apply encryption settings to the PDF file you selected and open the target folder after task is complete.

You can also use our Free PDF Encryptor Online program to encrypt PDF files with passwords online.