Unfortunately S4 for less inbuilt storage room, than it claims to have. Instead of 16GB of storage facility the phone offers only 8GB. One of the options is to use a micro SD card to give you more abilities. Some people enjoy greatly using this model SanDisk 64GB Class 10 Ultra. However, most of them would fit well and you can buy the SDs manufactured by Samsung. This way they have to be compatible and work flawlessly.