Jailbreak 4.3.4 iPhone 4/3Gs iPod Touch 4G/3G & iPad - Redsn0w 0.9.8B3

You will need to download redsn0w and the iPhone 4 4.3.4 firmware to your computer, you will need them to jailbreak your iPhone 4
Redsnow for Windows ( DOWNLOAD)

Redsn0w for Mac (DOWNLOAD)

iPhone 4 4.3.4 Firmware (IPSW) (DOWNLOAD)

Check out this video how to jail break your iphone 4 4.3.4 for  free Enjoy !!!