SONOFF S40 Lite

Quick verdict

The SONOFF S40 Lite is a tinkerer's favorite. Out of the box it works with eWeLink (cloud), but flash it with ESPHome and you get a fully local smart plug for pocket change. Note the Lite drops the energy monitoring found on the full S40 — it's basic on/off only. The 15A rating handles most household appliances. If you're comfortable with firmware flashing, this is one of the best value propositions in smart plugs.

Standout: ESPHome-flashable WiFi plug — go fully local with custom firmware.

Last checked: 2026-05-31

Compatibility snapshot

Why it stands out

• 15A capacity handles most household appliances
• can be flashed with ESPHome for fully local, cloud-free operation
• very affordable basic on/off WiFi plug

Reasons to hesitate

• no energy monitoring — the Lite drops the electricity statistics found on the full S40
• stock firmware is cloud-dependent via eWeLink
• ESPHome flashing required for best local experience

Best for

• ESPHome enthusiasts who want a cheap flashable WiFi plug
• budget on/off control for individual appliances

Avoid if

• you want plug-and-play local control without flashing firmware
• you need Matter or Thread support

Privacy and local-control notes

Stock firmware uses eWeLink cloud by default. Can be flashed with ESPHome for fully local operation. The SONOFF LAN mode also provides some local control without flashing.

Home Assistant support: supported · integration path: sonoff_lan / ESPHome.

Built with ESPHome — see our ESPHome guide for Home Assistant →

Buying reality check

Price notes: Very budget-friendly. One of the cheapest flashable WiFi plugs available.

Compare side by side: see plug comparisons →