SONOFF S40 Lite

Quick verdict

The SONOFF S40 Lite is a cheap 15A on/off plug - no energy monitoring (that's the full S40), no Matter, no Thread. Stock eWeLink firmware is cloud-connected by default, but the SonoffLAN integration drives it locally over your network, which is enough for most Home Assistant setups. Know this before you buy: the S40 series runs a Bouffalo Lab BL602 chip rather than an ESP, so despite SONOFF's flashable reputation you cannot put ESPHome or Tasmota on it. If flashing is the point, get the ESP8266-based S31 instead.

Standout: Cheap 15A Wi-Fi plug that answers locally over your LAN on stock firmware.

Notes last checked Jul 16, 2026.

Compatibility snapshot

Why it stands out

• 15A capacity handles most household appliances
• local LAN control with stock firmware via the SonoffLAN integration - no flashing needed
• very affordable basic on/off Wi-Fi plug

Reasons to hesitate

• no energy monitoring - the Lite drops the electricity statistics found on the full S40
• stock firmware is cloud-dependent by default via eWeLink
• BL602 chip - not an ESP plug, so ESPHome and Tasmota cannot be flashed onto it

Best for

• budget on/off control for individual appliances
• eWeLink owners who want local LAN control without flashing

Avoid if

• you want to run ESPHome or Tasmota on your plugs
• you need energy monitoring, Matter, or Thread support

Privacy and local-control notes

Stock eWeLink firmware talks to the SONOFF cloud by default, but the plug also answers on your LAN: the SonoffLAN custom integration (or the official eWeLink add-on) controls it locally over the network. Unlike the older ESP-based SONOFF plugs, the S40 series uses a Bouffalo Lab BL602 chip, so it cannot be reflashed with ESPHome or Tasmota - the community open-firmware option for BL602 is OpenBeken.

Home Assistant support: supported · integration path: SonoffLAN (eWeLink LAN) / eWeLink add-on.

Buying reality check

Price notes: Very budget-friendly. One of the cheapest 15A Wi-Fi plugs available.

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