At present the world advancement depends on its technology. IoT (Internet of Things) is the latest technology which connects the devices over a network using cloud computing and web applications to for efficient operation. Home security systems comprise a GSM module and Raspberry Pi with relay which is door security sensors. These systems can response rapidly when burglar intrudes in a home, office etc. And alerts the respective holder. Suspected activities are conveyed to user through SMS or CALL or SNAP SHOT of the burglar to the mobile by using GSM technology the total system is operated a single credit card sized computer that is Raspberry Pi.