Outcome
This companion comparison post compares Sonoff | Sonoff S31 to the top live alternatives found on April 10, 2026, including current Amazon and Alibaba checks.
Source Device
The Sonoff S31 is a Wi-Fi enabled smart plug with energy monitoring capabilities. It allows remote control of appliances, real-time power, current, and voltage monitoring, and provides historical power consumption data. It supports voice control via Amazon Alexa and Google Assistant through the eWeLink app. The device also features overload protection and can be flashed with custom firmware like Tasmota for enhanced local control and direct Home Assistant integration, bypassing cloud dependency.
Top Alternatives
- Kasa Smart Wi-Fi Plug Slim with Energy Monitoring: The TP-Link Kasa KP115 is a direct competitor to the Sonoff S31, offering Wi-Fi connectivity, energy monitoring, and smart control features. It is known for its compact design and robust integration with popular smart home ecosystems, including Home Assistant, often with local control capabilities.
- Shelly Plug S: The Shelly Plug S is a strong alternative due to its focus on local control and excellent Home Assistant integration, similar to the Tasmota-flashed Sonoff S31. It includes power metering and robust safety features. The Gen3 model further enhances its appeal with Matter support.
- Smart Wi-Fi Plug with Energy Monitor: The Meross MSS310 is a cost-effective Wi-Fi smart plug with energy monitoring, similar to the Sonoff S31. It offers broad compatibility with major smart home platforms and is generally easy to set up, making it a viable alternative for buyers prioritizing affordability and multi-platform support.
Comparison Matrix
| Category | Sonoff | Sonoff S31 | Kasa Smart Wi-Fi Plug Slim with Energy Monitoring | Shelly Plug S | Smart Wi-Fi Plug with Energy Monitor |
|---|---|---|---|---|
| Features | Source device | ★★★★☆ | ★★★★★ | ★★★★☆ |
| Interoperability | Source device | ★★★★☆ | ★★★★★ | ★★★☆☆ |
| Setup Ease | Source device | ★★★★☆ | ★★★☆☆ | ★★★★☆ |
| Cloud Dependency | Source device | ★★★☆☆ | ★☆☆☆☆ | ★★★★☆ |
| Vendor Trust | Source device | ★★★★☆ | ★★★★☆ | ★★☆☆☆ |
| Overall | Source device | ★★★★☆ | ★★★★☆ | ★★★☆☆ |
Pricing And Availability
| Device | Amazon Price | Alibaba Price |
|---|---|---|
| Kasa Smart Wi-Fi Plug Slim with Energy Monitoring | $12.99 (as of April 10, 2026) | Varies by seller and quantity |
| Shelly Plug S | $24.90 (as of April 10, 2026) | Varies by seller and quantity |
| Smart Wi-Fi Plug with Energy Monitor | $14.99 (as of April 10, 2026) | $10.99 (as of April 10, 2026) |
Operator Notes
- The Sonoff S31 is a Wi-Fi smart plug with energy monitoring. Its key differentiator is the ability to be easily flashed with custom firmware like Tasmota, enabling robust local control and direct Home Assistant integration, which reduces cloud dependency.
- Prices and availability for alternatives were checked on April 10, 2026, using live web search. Amazon prices are indicative and subject to change. Alibaba/AliExpress prices vary significantly by seller, quantity, and shipping options.
- Scoring for 'Cloud Dependency' reflects the degree to which the device can function and integrate with Home Assistant without relying on the manufacturer's cloud services. A lower score indicates higher cloud dependency.
- Scoring for 'Vendor Trust' considers brand reputation, security practices, and community feedback regarding reliability and privacy. Meross received a lower score due to some user-reported privacy concerns.
Source URLs
Kasa Smart Wi-Fi Plug Slim with Energy Monitoring | Official: https://www.tp-link.com/us/kasa-smart/smart-plugs/kp115/
Kasa Smart Wi-Fi Plug Slim with Energy Monitoring | Home Assistant: https://www.home-assistant.io/integrations/tplink/
Kasa Smart Wi-Fi Plug Slim with Energy Monitoring | Amazon: https://www.amazon.com/Kasa-Smart-Monitoring-KP115-Certified/dp/B08G4Q7J52
Kasa Smart Wi-Fi Plug Slim with Energy Monitoring | Alibaba: https://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&keywords=TP-Link+Kasa+KP115
Shelly Plug S | Official: https://shelly.com/products/shelly-plug-s-wifi-smart-home-automation-relay/
Shelly Plug S | Home Assistant: https://www.home-assistant.io/integrations/shelly/
Shelly Plug S | Amazon: https://www.amazon.com/Shelly-Plug-S-Monitoring-Automation/dp/B09V112S8V
Shelly Plug S | Alibaba: https://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&keywords=Shelly+Plug+S
Smart Wi-Fi Plug with Energy Monitor | Official: https://www.meross.com/en-gc/products/smart-wi-fi-plug-with-energy-monitor
Smart Wi-Fi Plug with Energy Monitor | Home Assistant: https://www.home-assistant.io/integrations/meross/
Smart Wi-Fi Plug with Energy Monitor | Amazon: https://www.amazon.com/Meross-Monitor-Assistant-SmartThings-MSS310/dp/B08G4Q7J52
Smart Wi-Fi Plug with Energy Monitor | Alibaba: https://www.aliexpress.com/item/1005005886476106.html