The Samsung Galaxy S4 and the S3 are two handsets that have been popular with people and many people still own them today. However many handsets are locked and if you want to take the handset to a different carrier the device has to be unlocked. Now there is a way that owners can do it thanks to a leaked unlock code that is going around.
The leaked code allows people to unlock their Samsung Galaxy S4 or S3 so that they can choose a carrier to get a better deal.
If you want to unlock your handset you first get a new SIM card and put it into the device. You can then turn the handset back on and go to the dial pad and you can then type in the code *#197328640#. You can then follow the steps below.
 UMTS >  Debug Screen >  Phone Control >  Network Lock > Options  Perso SHA256 OFF.
You should then wait for 30 seconds and you can then head back into the main menu and you should see Network Lock. You can then choose  NW Lock NV Data INITIALLIZ and if all has gone to plan you will now have a handset that is unlocked.
The unlock code is said to work with the Samsung Galaxy Note 3, Note 2, S4 and the S3 so give it a try.