Sonoff Smart Switches

Description

Sonoff smart switches are WiFi-enabled relay modules that retrofit existing electrical fixtures with smart control capabilities while preserving manual switch operation. The product line ranges from basic single-relay modules to dual-channel switches with power monitoring, temperature sensing, and advanced features. Designed for DIY installation in junction boxes, Sonoff devices work natively with the eWeLink cloud app but can be flashed with Tasmota or ESPHome firmware for complete local control, making them a favorite among Home Assistant builders seeking affordable, hackable automation hardware.

Overview

Device Score Summary

Category	Score	Rationale
Features	★★★★☆	Excellent feature set across product line with power monitoring, multi-channel control, and sensor options. Lacks dimming on most models
Interoperability	★★★★★	Outstanding flexibility with native app, local API, and custom firmware options. Tasmota/ESPHome enable perfect Home Assistant integration
Setup Ease	★★★☆☆	Electrical knowledge required for wiring. Flashing firmware adds complexity but dramatically improves capabilities
Cloud Dependency	★★★★☆	Stock firmware uses cloud push but has local API. Tasmota/ESPHome provide complete local control with zero cloud communication
Vendor Trust	★★★★☆	ITEAD/Sonoff is established smart home brand with active development. Recent chip changes frustrate flashers but products remain reliable
Overall	★★★★★	Best value in smart switches for Home Assistant builders willing to flash firmware. Unbeatable combination of price, features, and local control

★★★★★ Exceptional | ★★★★☆ Very Good | ★★★☆☆ Good Enough | ★★☆☆☆ Frustrating | ★☆☆☆☆ Avoid

Features

WiFi connectivity (2.4GHz) with ESP8266 chipset enabling custom firmware
Maintains manual switch operation alongside smart control via two-way wiring
Multiple models supporting 1-4 channels, 10A-16A loads per channel
Select models include power monitoring, temperature/humidity sensing, and energy reporting
Compact form factor designed to fit inside standard electrical boxes
Native eWeLink app support with Alexa, Google Assistant, and SmartThings compatibility
Open REST API for LAN control when using stock firmware
Flashable with Tasmota or ESPHome for complete local control and customization

Specifications

Price	$6-25 depending on model (Basic $6-9, Mini R2 $9, Dual R3 $15-20, TH $15-25)
Protocol	WiFi (2.4GHz)
Hub Required	No
Power	Wired (90-250V AC input, 10-16A load per channel)
Cloud Dependency	Cloud Push (stock firmware) or Local (Tasmota/ESPHome)
HA Integration	Community (Sonoff LAN) or Custom (Tasmota/ESPHome)
Voice Control	Alexa / Google / Siri (via HA)
Dimensions	Basic: 3.5 x 2.4 x 0.9 inches, Mini R2: 1.6 x 1.6 x 0.8 inches
Warranty	1 year (voided if flashed with custom firmware)

Home Assistant Integration

Integration Method: Tasmota (MQTT)

Requirements: USB-to-TTL adapter for flashing Tasmota firmware, MQTT broker configured in Home Assistant, basic soldering skills to access programming pins
Entities: Switch entities for relay control, power sensors for monitoring models, temperature/humidity sensors on TH variants, optional diagnostic entities
Setup: Flash Tasmota firmware via serial connection, configure WiFi and MQTT settings through web interface, devices auto-discover in Home Assistant via MQTT discovery
Notes: Tasmota provides instant local response with no internet dependency. ESPHome is alternative for native API integration. Stock firmware users can use Sonoff LAN custom component for local control without flashing.

Practical Considerations

Electrical Safety: Installation requires working with high-voltage AC wiring. Turn off breakers and verify with non-contact tester before handling
Flashing Process: Newer models have unpopulated headers requiring soldering to access programming pins. Some recent versions use incompatible chips that cannot run Tasmota
Box Space: Verify adequate depth in junction box before purchasing. Crowded boxes may not accommodate device plus wire nuts and existing wiring
Two-Way Wiring: External switch connects to designated input pins, not in series with load. Review wiring diagrams carefully to avoid miswiring
Load Compatibility: Not suitable for all load types. LED bulbs may cause flickering, motors may exceed inrush current ratings without soft-start
WiFi Reliability: Requires strong 2.4GHz signal at installation location. Metal junction boxes can attenuate signal, use external antenna models if needed
Firmware Updates: Stock firmware updates may break custom firmware. Disable OTA updates in eWeLink app before flashing Tasmota