The Best Smart Thermostats for a More Energy-Efficient Home

Best Overall

Ecobee Smart Thermostat with Voice Control

4.9

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The Ecobee Smart Thermostat with Voice Control has many great features, comes with a remote room sensor with the option to add more, and works with all of the major smart home systems, which is why it’s our pick for the best overall smart thermostat.

This model is the fifth generation of Ecobee’s smart thermostat hardware. It has a color touchscreen display, built-in speaker, voice controls supported by Amazon’s Alexa virtual assistant, and even supports advanced Alexa functionality like calling, messaging, and the drop-in intercom feature. The quality of the speaker is similar to an Echo Dot, which is a big improvement over previous generations of Ecobee hardware.

If you don’t use Alexa, the fifth-generation Ecobee also has built-in support for Siri as long as you have a HomePod or HomePod Mini on your network. You can also connect to Google Home, but Google Assistant doesn’t work directly on Ecobee. That means Google Home users need to issue voice commands to the Ecobee through a connected Nest speaker or the phone app.

Ecobee supports remote sensors that monitor both temperature and presence, and you get one when you buy the thermostat. This sensor allows the system to monitor the temperature at the thermostat and somewhere else in your home, know whether people are there, and adjust the heating or cooling accordingly. Small homes get by just fine with one sensor, but you can add up to 32 sensors if you have a large home with many rooms across multiple floors.

Price at time of publish: $220

_{Dimensions: 4.29 x 1 x 4.29 inches︱Power Source: AC/DC, includes power extender kit︱Works With: Amazon Alexa, Google Assistant, Apple HomeKit, and more︱Display: 3.5-inch LCD touchscreen}

Best Budget

Amazon Smart Thermostat

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The Amazon Smart Thermostat has an understated design and a rock-bottom price tag, but that unassuming exterior hides a surprising amount of functionality. Amazon partnered with Resideo to manufacture this smart thermostat, and its hardware has a lot in common with the much more expensive Honeywell T9 and T5 thermostats. It also leans on Alexa and the Hunches feature to approximate Google’s best-in-class learning functionality, which allows it to automatically adjust the temperature in your home based on past preferences and current activity.

While this is the best option for adding smart functionality to an HVAC system on a budget, the glaring issue is that it only works with one smart home system. If you don’t use Amazon’s Alexa, that may be an issue. This thermostat doesn’t support Google Assistant, HomeKit, or SmartThings. Alexa integration is seamless, but that’s only useful if you use Alexa in the first place.

Price at time of publish: $60

_{Dimensions: 3.56 x 0.84 x 3.56 inches︱Power Source: AC/DC, C-wire required︱Works With: Amazon Alexa︱Display: Basic LED with touch controls}

Best With Machine Learning

Google Nest Learning Thermostat

4.9

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The third-generation Nest Learning Thermostat uses Google’s advanced machine learning technology to learn your daily routines and automatically adjust the temperature in your home, which is why it’s our pick for the smartest smart thermostat around. It can remember the temperature selections you make throughout the day, determine when you’re home and away, and eventually set the temperature just right without any further input.

The Nest works well with Google Assistant and Alexa for voice controls but doesn’t have HomeKit support. Voice controls and smart home integration aren’t absolutely necessary, though, since you typically only need to change the temperature manually whenever you need it to be hotter or colder than your established norm. This model also lacks a remote sensor, but you can purchase Nest Temperature sensors separately for more control over conditions in certain spaces.

Price at time of publish: $300

_{Dimensions: 3.3 x 1.21 x 3.3 inches︱Power Source: AC/DC, battery (for backup power)︱Works With: Google Assistant, Nest, Amazon Alexa︱Display: 2-inch color LCD}

Best Display

Emerson Sensi Touch Wi-Fi Smart Thermostat

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The Sensi Touch Smart Thermostat features a big, colorful 4.3-inch full-color LCD touchscreen that sets it apart from the crowd. The display shows the current temperature prominently instead of the set temperature, so you can always see how hot or cold it is at a glance, even from across the room. The screen is smooth and responsive as well, so it’s as functional as it is attractive.

The thermostat controls allow you to set up to four temperature changes per day, and the mobile app makes scheduling easy—letting you add additional changes in increments as small as 15 minutes. It doesn’t have a presence sensor, and you can’t add remote sensors, but it does support geofencing. That means you can have the heat or air conditioning turned on only when you’re actually home, which the system determines based on the location of your phone.

Price at time of publish: $169

_{Dimensions: 5.63 x 1 x 3.2 inches︱Power Source: AC/DC, C-wire required︱Works With: Amazon Alexa, Google Assistant, Samsung SmartThings, Apple HomeKit︱Display: 4.3-inch full-color LCD touchscreen}

Best With No C-Wire

Sensi Emerson Sensi Wi-Fi Smart Thermostat

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The Sensi Smart Thermostat could be what you’re looking for if your existing thermostat doesn’t have a C-wire and you don’t want to pay to install it. You can connect it to a C-wire if your system already has one, but it’s fully functional even without that extra power source. It does run on batteries, which means popping it open to install fresh ones from time to time, but that’s unavoidable if you want a smart thermostat that doesn’t require a C-wire.

The monochrome display is easy to read but looks a little dated compared to other smart thermostats. The app looks better and allows you to control the thermostat remotely. This thermostat supports highly customized scheduling to control the temperature at different times of day and on different days. It also supports geofencing to switch off when you leave the house and back on when you return.

Price at time of publish: $127

_{Dimensions: 5.88 x 1 x 3.75 inches︱Power Source: Battery, AC/DC︱Works With: Amazon Alexa, Google Assistant, Samsung SmartThings, Apple HomeKit︱Display: 5-inch monochrome}

Best for Big Houses

Honeywell Home T9 Wi-Fi Smart Thermostat

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The Honeywell Home T9 Smart Thermostat with Sensor is the best smart thermostat for large homes because it comes with a remote sensor, and you can add up to 19 additional units. It’s difficult to regulate the temperature in large homes with a single thermostat and no zone control, but the T9 and its remote sensors do the best job possible. Instead of only relying on temperature readings taken at the thermostat itself, the T9 considers the temperature and humidity throughout your home when making adjustments.

The Honeywell T9 doesn’t have zone control, but you can use multiples of this thermostat model if your house has multiple zones. Each zone needs its own thermostat and sensors, and then you can control the entire system through the Resideo app or your connected smart home system. For smart home connectivity, the T9 supports Alexa, Google Assistant, SmartThings, and HomeKit.

Price at time of publish: $180

_{Dimensions: 3.7 x 0.94 x 4.92 inches︱Power Source: AC/DC, includes adapter︱Works With: Amazon Alexa, Google Assistant, Samsung SmartThings, Apple HomeKit︱Display: Full-color touchscreen}

Best for HomeKit

Ecobee 3 Lite

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The Ecobee3 Lite is an excellent low-cost alternative to our top overall pick, the Ecobee Smart Thermostat with Voice Control, with the same fantastic HomeKit support at a much lower price. Ecobee’s HomeKit support is so strong, in fact, that it’s the only smart thermostat manufacturer recommended by Apple. HomeKit integration even allows you to implement geofencing, a feature that adjusts your thermostat based on whether you’re home, which the Ecobee3 Lite can’t do on its own. In addition to excellent HomeKit support, the Ecobee3 Lite also supports Alexa, Google Assistant, and SmartThings.

While this smart thermostat doesn’t come with remote sensors, it supports these units, which you can purchase separately. Remote sensors allow you to monitor the temperature in different areas of your home and set the Ecobee3 Lite accordingly, and they also work with the occupancy detection feature. That means the Ecobee3 can automatically adjust the temperature if it notices the presence of someone in a room where you have placed a sensor.

Price at time of publish: $150

_{Dimensions: ‎4 x 21.4 x 4 inches︱Power Source: AC/DC, power extender kit included︱Works With: Apple HomeKit, Amazon Alexa, Google Assistant, Samsung SmartThings︱Display: 3.5-inch full-color LCD touchscreen}

Best for Baseboards

Mysa Smart Thermostat

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The Mysa Smart Thermostat is the best option if you have electric baseboard heaters. It features a slick, minimalist design with touch controls that allow you to easily adjust the temperature right on the thermostat. It can also connect to your Wi-Fi network to facilitate app control. When connected to your Wi-Fi network, this thermostat supports voice commands and integration with Alexa, Google Assistant, and HomeKit.

While the display is less informative than other models, the Mysa app allows you to monitor and control all of your Mysa smart thermostats from a central location. That includes scheduling when each heater should turn on and off, geofencing to turn the heaters off when you leave and on when you get back, and manual controls. The app also provides energy insights, which allow you to see exactly how much power your heaters are using and make adjustments to save money on your power bill.

Price at time of publish: $139

_{Dimensions: 3.5 x 0.8 x 5.1 inches︱Power Source: AC/DC︱Works With: Amazon Alexa, Google Assistant, Apple HomeKit︱Display: LED}