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SONOFF S31 WiFi Smart Plug with Energy Monitoring, 15A Smart Outlet Socket ETL Certified, Work with Alexa & Google Home Assistant, IFTTT Supporting, 2.4 Ghz Wi-Fi Only 1-Pack

  • Based on 1,435 reviews
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Availability: Only 2 left in stock, order soon!
Fulfilled by Amazon

Arrives Tuesday, Dec 31
Order within 12 hours and 51 minutes
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Size: S31 1-Pack


Features

  • [Monitor Energy Consumption]:Keep track of real-time power, current and voltage of your appliances on App.and Measure your appliances power consumption for 100-day daily/monthly energy usage data and total electricity cost.
  • [Smart Remote Control Plug]: You can remotely/timely control ON/OFF any connected home appliance via APP eWeLink on your smart phone or tablet. No distance/time limitation.
  • [Set time schedules for the lights and home appliances]: You can set countdown/single/repeat timers to auto-turn on/off the WiFi controlled outlet on App. One tap ON/OFF Energy Saving.
  • [Share control of devices to others]: You can simply share control of your home appliances to others so that they can also turn on/off the devices remotely.

Operation Mode: ‎Off


Current Rating: ‎15 Amps


Brand: ‎SONOFF


Item Dimensions LxWxH: ‎3 x 2 x 1.02 inches


Mounting Type: ‎Plug-In Mount


International Protection Rating: ‎50


Controller Type: ‎Alexa,Google Assistant,IFTTT


Control Method: ‎App, Remote, Voice


Connectivity Protocol: ‎Wi-Fi


Wattage: ‎1800 watts


Unit Count: ‎1 Count


Manufacturer: ‎SONOFF


Part Number: ‎S31


Item Weight: ‎3.2 ounces


Product Dimensions: ‎3 x 2 x 1.02 inches


Item model number: ‎S31


Size: ‎S31 1-Pack


Voltage: ‎120 Volts (AC)


Item Package Quantity: ‎1


Batteries Included?: ‎No


Batteries Required?: ‎No


Date First Available: September 26, 2019


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, Dec 31

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Top Amazon Reviews


  • Own Over 25 Of Them, Tasmotized And Mostly Happy
Size: S31 2-Pack
Like many other reviewers, I have purchased this particular switch to install Tasmota on. I use them for energy monitoring, and in some cases their "original intent" - outlet switching, in my home. I buy whatever pack is cheapest per unit at the time, be it 1, 2 or 4 pack versions. They're all the same in my experience. To get them installed with Tasmota, I first tried to solder leads to them. Then I tried to solder pin headers and that was a little bit easier. I'm slightly beyond entry level skill with soldering, but I destroyed at least three units in this learning process. I finally graduated to micro-grabber electrical test clips and have ripped through over two dozen conversions now without incident. Let's be frank. I'd rather Sonoff just offered Tasmota OS from the get-go, or made these over-the-air flashable. I will settle for nothing less than local control and I'm definitely not itching for a "new and different cloud solution or app." I'd prefer not to hack these devices in the first place and if Sonoff works towards preventing this from a hardware or software standpoint, I will buy no more of them. At the time of this writing (March 2022), this is probably one of the cheapest way to get local energy monitoring and basic 15 amp capable on/off outlet switching. I use Home Assistant for my home automation platform. These are fully compatible with their new "energy monitoring" dashboard. This provides me with significant insight into my home's energy use, especially now that they're widely distributed to the overwhelming majority of my outlets. I usually capture between 13-18 kilowatt hours per day, the bulk of my usage. To be clear, I use "higher grade" energy monitoring switches in "mission critical" applications (furnace, fridge, etc.), but these are great even for non-mission critical high amp usage scenarios up to 15 amps. I've pushed some of mine well up to the limits and haven't had any major problems or sparks fly. Out of a couple dozen, I've had one actual device failure. Oddly enough, even with different firmware, different units operate differently on my WiFi. Some stay connected to Wifi 100% of the time, others intermittently connect throughout the day. I don't lose any granular Home Assistant data because of this, nor are they ever inaccessible and fail to turn on/off. I don't have a good answer as to why different units behave differently with the same software. Odd behavior, but it doesn't result in problems. I really can't complain anyway, I'm using them well outside of the manufacturer's intended use. Build quality is "good enough" but I wish there was a bit more consistency. Since the majority of buyers are intending to hack these, I really wish they wouldn't cinch down some of the poor-quality screws like they are Shee-Ra or the Hulk. I've destroyed way more screws than I've wanted, and that's with the "perfect screw removal tool" which I've determined to be a 2.0mm flathead screwdriver. Again, I just wish I could buy a decent quality, super cheap, 15 amp capable smart switch product with the OS of my choice out of the gate. I've used these to solve VERY REAL problems in my home. From triggering outlets based on other inputs to making serious dents in energy conservation, I believe the $200ish dollars I've put into these Sonoff S31 units will eventually pay for themselves. It's fairly easy for me when I'm paying almost $0.25 per kilowatt hour, others might not have as good of an ROI. If anything, I've achieved "some level" of energy usage consciousness. I've killed and/or automated quite a few parasitic energy draws I wasn't even aware of, and have easily increased my automation abilities at the same time. It's important to know that these utilize about 2 watts each, just to function. This might not seem like much, but with two+ dozen of them running 24 hours a day - we're talking about a ~50 watt constant load just to monitor outlet energy. For me, I've killed and automated much more than that, so I'm "in the black" as it were. It's important, at least for me, to keep tabs on the cost and value of energy monitoring. I'm hoping I can continue to use these to save at least $500 in energy in the next 5 years, and so far, that seems to be a reasonable goal based on how I use them. Lastly, I don't want to get too much into minutia, but you need a fairly robust WiFi network to support the "internet of things" over WiFi. Personally, I utilize multiple networks, including Lutron, Z-Wave, Zigbee and WiFi to get there. Put simply, I don't use these "cheap and ubiquitous" hacked WiFi devices to service mission critical applications in any way. If a failure would cost me a fair bit of money, I spend more than $10 to capture energy usage and (sometimes) provide switching capabilities. +4 stars for being a hackable and very useful device overall. You can debate about that last star, even I waver between 4 and 5 stars. They provide much value for not much dollar and a reasonable +/-2 year path to return on investment for many people that are trying to optimize energy consumption or provide local, automated switching controls. ... show more
Reviewed in the United States on March 20, 2022 by J. Whiteside

  • NOT ESP-based, will not work with Tasmota firmware
Size: S40 4-Pack
***Not Tasmota compatible. This was my own mistake.*** These probably work perfectly in the advertised cloud interface, and integrating with Alexa, although I won't be using them in that capacity. I mistakenly purchased these to flash with the Tasmota firmware, as I'm trying to make my own, locally-controlled smarthome environment. I was unaware that this new model is not based on the ESP8266 like previous versions were, but instead they are built on the BL602 chip. I found some talk of a similar custom firmware for BL602 IoT devices and I will be attempting to use it, but if you want to flash custom firmware onto a smart-plug, just get the older model and avoid this headache. These are nearly impossible (and probably dangerous) to disassemble, and the community around this chip is not nearly as large or well-documented as the ESP community is. ... show more
Reviewed in the United States on January 10, 2023 by Andrew Maples

  • Pain in the A55 to pair, but finally found a way
Size: S31 2-Pack
Tried for days to pair and almost returned them. Most only searches so older versions of the app and the app is not intuitive at all. It is very picky with how your wifi is set up. The Name(ssid) and passwords Can Not have any spaces or special characters. This was a challenge because we are not able to change these without have to re setup all our other devices. Some are security cameras that are very difficult to get to (26' high and 1/4 mile from our router). Our router is only 2.4ghz but the app kept acting as though we were trying to connect to a 5ghz router. Ultimately we had to add a Guest Account named Letters only and set the password with the same restrictions (which makes for a very weak password). Once paired...whew, It seems to be working. The app does Not give the level of detail I was hoping for. It only provides total daily power usage or instantaneous usage. I wanted to see what time the refrigerator defrost heater came on, for how long and how much power it used but the app doesn't do this. With all this considered it is a good value and we may even buy more now that we are able to pair them. One star deducted due to the app, not the switch itself. Although, if the devices continues to work well over time without loosing connectivity or failing we will update to full 5 stars. We were able to determine the fridge pulls about 1amp/120watts while the compressor is running and a total usage of about 0.9kw over 24hrs. The hair drying on high heat and fan pulls over 13amps/1600watts which is almost the max rating of the device. Be careful not to overload. Only ran for a moment so can't speak to how long it can handle this level of current draw. Lastly the basic math calculation is not 100% accurate which should be very easy to accomplish. Volts x Amps = Watts. The device measures the amps and the volts and calculates the watts. They were reasonably close but not perfect. See image attached, should be 126 watts. ... show more
Reviewed in the United States on March 12, 2022 by Tamra

  • They work and are convenient
Size: S40 4-Pack
I have one I use in conjuction with a motion detector to turn a light on when I enter my bedroom and it works flawlessly. As at the time I did not have a zigbee gateway, I bought the wiwfi version. I have no complaints at all.
Reviewed in the United States on November 14, 2022 by Angry Black Man

  • Effective at finding power draining appliances
Size: S31 1-Pack
I bought a single S31 to figure which of my appliances was the most power-draining. What I did is simply use the single S31 power plug to monitor each suspect appliance for 2-3 days. The Android App has a kWh power consumption meter which you can start and stop. I was able to find out that my refrigerator was actually the culprit, using about 2kWh a day. I would have given the S31 a 5-star but for the fact that the software app is not the most intuitive to use. But it does the job and the S31 plug itself is only $15. ... show more
Reviewed in the United States on October 9, 2022 by Luke Liem

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