Which Android version first added Bluetooth Low Energy support in 2013?

Android 4.3 Jelly Bean first added Bluetooth Low Energy support in 2013.

Android 4.3, released on July 24, 2013, added platform support for Bluetooth Low Energy, commonly abbreviated BLE or Bluetooth LE. The feature enabled Android devices to communicate with low-power accessories such as fitness sensors, beacons, health monitors, and other small peripherals.

Bluetooth Low Energy was designed for brief, efficient exchanges rather than the continuous high-throughput connections associated with classic Bluetooth audio. That distinction made it especially useful for battery-powered accessories that needed to run for long periods.

The answer is sometimes confused with Android 4.4 KitKat because KitKat followed only a few months later, but BLE support arrived in Android 4.3. Hardware compatibility still mattered: an Android version could provide the software framework, but a device also needed suitable Bluetooth hardware.