ESPHome

What it is

ESPHome is firmware, not a hub. A device is described in a YAML file or the visual Device Builder, and ESPHome generates and flashes the firmware. It targets ESP32, ESP8266 and RP2040/RP2350 boards, plus BK72xx, RTL87xx, LN882 and nRF52 chips found in many off-the-shelf plugs and bulbs. After the first flash, updates can go over the air.[1][8]

The hub is whatever the device talks to, which in practice is Home Assistant. Its ESPHome integration discovers ESPHome devices and controls them over the local network.[1][6]

Which paths it supports

The native API is a compact protocol-buffer connection with no broker in between. MQTT is available as an alternative.[2][7]

On ESP32-C5, C6 and H2 and on nRF52, ESPHome can join a Zigbee network as an end device or router, with ZHA or Zigbee2MQTT as the coordinator. It supports the Home Automation profile only. The same chips can join a Thread network through ESPHome's OpenThread component, which needs a Thread border router.[3][4]

The Bluetooth proxy turns an ESP32 into a remote Bluetooth LE radio for Home Assistant. It forwards advertisements and, on ESP32 and RP2040, active connections.[5]

Local or cloud

ESPHome devices work with Home Assistant locally, with no cloud account involved.[1][6]

Limitations

• Zigbee support exposes only basic properties, and Wi-Fi access point mode cannot run alongside Zigbee. The docs report the ESP32-H2 as more reliable than the C6.[3]
• On Thread, OTA updates fail on sleepy devices with a poll period set, and sleepy end device support is incomplete.[4]
• The Bluetooth proxy handles BLE only, with three active connection slots by default on ESP32.[5]