SONY XPERIA C SERIES FIRMWARE

Download Sony Xperia C series Stock ROM (firmware)

XPERIA C3 D2533  

XPERIA C3 Dual D2502  

XPERIA C4 Dual E5333  

XPERIA C4 E5303  

Create a backup of your of your personal data like sms, contacts etc before you flash or update your device.
Flash/unbrick or upgrade Sony Xperia devices with these ROMs using flashtool
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Learn how to unlock or relock Sony Xperia bootloader from here