Ecobee SmartThermostatSource: Christopher Close / iMore

Best Smart Thermostat iMore 2021

With a smart thermostat, especially one that is equipped with HomeKit, you'll be able to easily control the temperature within your home, from pretty much anywhere, even with your voice. You can even set up things like scenes and automations, making your life even easier and giving you comfort without a second thought. We think that the best smart thermostat that you can get is the Ecobee SmartThermostat, because it works with HomeKit as well as Alexa, and it's the easiest to set up and use.

Best Overall: Ecobee SmartThermostat

Ecobee SmartThermostat SideSource: Christopher Close / iMore

The Ecobee SmartThermostat is the best smart thermostat for anyone who wants to control their home environment using a voice assistant. With the Alexa-enabled Ecobee Smart Thermostat, you get all the magic of the HomeKit plus built-in Alexa voice control. Even better, thanks to the built-in speaker and microphone setup, Alexa is just as powerful on the Ecobee SmartThermostat as it is on Amazon's Echo products.

Ask Alexa to set a timer, adjust the lighting, give you the steps to a recipe, play some jazz. You can do it all right from your smart thermostat. You can also, of course, use Alexa to adjust the temperature in your home, but that's just one tiny detail. It comes with embedded microphones that feature far-field voice recognition (the same technology that makes the Amazon Echo hear you from across the room) and a speaker that makes Alexa sound loud and clear, despite coming from a thermostat fastened to your wall.

With HomeKit compatibility, you get full support for Siri control, including the ability to change temperature with your voice and trigger more complex actions with scenes, using the best iPhone, iPad, or Apple Watch. This device also supports IFTTT, Samsung SmartThings, Alexa, Google Assistant, and many more integrations.


  • Built-in Alexa control
  • Full Siri and HomeKit control
  • Remote sensor compatibility


  • Expensive
  • No local app control
  • Not for the privacy-minded

Best Overall

Ecobee Smart Thermostat Render Cropped

Ecobee SmartThermostat

Full featured

The ecobee SmartThermostat includes a remote sensor that reports temperatures all around your home and not just one location.

Best for Small Locations: Ecobee 3 Lite

Ecobee 3 Lite LifestyleSource: ecobee

The Ecobee 3 Lite is more or less an Ecobee smart thermostat without the room sensors. It has all the same great features, including HomeKit compatibility and Siri control; it's just constrained to the area where you install the main unit out of the box. However, you can buy remote sensors separately to see the temperature in other areas of your home if you choose to expand later.

The main differences between it and the Ecobee 4 are the lack of an integrated Amazon Alexa speaker, room sensor, and occupancy detection. The Ecobee 3 Lite is also slightly smaller than the newer model but isn't compatible with as many heating/cooling systems.


  • Low cost
  • Compatibility
  • Easy installation


  • Room sensors not included
  • Incompatible with certain equipment
  • No occupancy detection

Best for Small Locations

Ecobee 3 Lite Render Cropped

Ecobee 3 Lite

Smaller, but capable

If you have a small home, or you simply don't feel the need for extra sensors in other rooms, go with the Ecobee 3 Lite.

Best Alternative: Google Nest Learning Thermostat

Nest Learning ThermostatSource: Nest

The Google Nest Learning Thermostat remains a popular choice even though it's not one of the newest smart thermostats on the block. With a HAL-like dial that still looks futuristic, the Nest device is largely simple to use and works great with the Nest app for iOS. It also supports the Works with Nest program, which provides integrations with dozens of other smart home products, including home security systems, cameras, locks, and more.

By definition, the Nest Learning Thermostat takes the temperatures that you like, then builds a schedule that it believes will suit you. In doing so, you'll be more comfortable in your home while also saving on heating and cooling bills. As part of its learning, the thermostat also adapts to the changing seasons in your area.


  • Compatible with 95% of HVAC systems
  • Multiple color options
  • High-quality materials


  • Pricey
  • Learning features may not work for all
  • Limited integrations

Best Alternative

Nest thermostat in silver showing active heating on a white background

Google Nest Learning Thermostat

Alternative solution

The Nest Learning Thermostat is a great alternative if you don't need HomeKit and have other Nest products in your house.

Best Value: Honeywell Lyric T5

Honeywell Lyric T5 ThermostatSource: Honeywell

You don't have to spend a lot of money to get a high-quality smart thermostat. The Honeywell Lyric T5 provides most of the features of the more expensive options but for less money. The main drawback of this lower cost: a design that looks a little bit dated, even though it features all of the smart goodies. Beyond this, you still get to experience voice control, scheduling, smart alerts, and more through integrations with HomeKit and Alexa.


  • Smart alerts
  • Price (look for discounts)
  • Flexible scheduling options


  • No humidity and motion sensors
  • Requires C-Wire
  • Somewhat dated design

Best Value

Honeywell Lyric T5 Thermostat

Honeywell Home Lyric T5

Cost effective

Despite its dated design, the Honeywell Lyric T5 offers flexible scheduling, HomeKit, and location-based temperature control.

Best No-Hassle: Google Nest Thermostat E

Nest E Thermostat LifestyleSource: Nest

The Nest Thermostat E, like its more expensive sibling, learns as you use it, creating an automatic schedule for heating and cooling. It also works with voice assistants and features most of the same sensors as the Nest Learning Thermostat. Of course, it is missing the metal casing and color options, that Nest is famous for. However, the real downside is that it doesn't work with quite as many HVAC systems as the Learning Thermostat, sporting 85% compatibility.


  • Cheaper than the Learning Thermostat
  • Works with "most" heating and cooling setups
  • Fully featured


  • No color options
  • Basic design
  • Learning functions may not fit all

Best No-Hassle

Nest thermostat e in white on a white background

Google Nest Thermostat E

Almost as good for less

The Nest Thermostat E's design doesn't mean you have to settle for less. This thermostat includes almost every feature around.

Best Screen: Emerson Sensi Touch

Emerson Sensi Touch in white in a living room settingSource: Emerson

Emerson's Sensi Touch thermostat features a large widescreen touch display making it easy to make adjustments on the device itself. Speaking of changes, the Sensi Touch has quick access shortcuts to standard features such as turning on just house fan, directly from the home screen.

This thermostat also includes a backlight option that lights the area around it at night, preventing it from lighting up your room with a huge display. This backlight is also handy for the installation process, as it lights up the wiring terminals, giving you a better look at where your wires are going.


  • Huge screen
  • Compatibility
  • Two-color options


  • Room sensors not included
  • Incompatible with certain equipment
  • No occupancy detection

Best Screen

Emerson Sensi Touch in White

Emerson Sensi Touch

Wide screen

Emerson's Sensi Touch has a big, beautiful touchscreen, smart features, and a handy backlight for locating it at night.

Convenience and control with the best smart thermostats

Having the best smart thermostat in your home offers convenience and control, all while saving you a little money in the process. For some, the thermostat is not always in the most accessible location — this is where app voice control comes in. Changing the temperature in your home from the comforts of your couch or bed is more than worth the cost of admission, and scheduling features are the icing on the cake.

For most people, the Ecobee SmartThermostat is the best smart thermostat around. The Ecobee SmartThermostat is fully featured and caters to folks who are all-in on Apple with other great HomeKit accessories, or even those who prefer Alexa control. Over time, you can expand your Ecobee SmartThermostat's footprint by adding additional room sensors. Ultimately, your decision should come down to how much you want to control the temperature in your home and where.

The team that worked on this guide

Author: Christopher Close

Christopher Close is iMore's resident smart home expert. He is frequently testing out all of the smart home accessories, such as smart thermostats, as well as anything else with HomeKit integration.


Bryan M Wolfe is a dad who loves technology, especially anything new from Apple. A Penn State graduate, Bryan is also a huge fan of the New England Patriots. Thanks for reading. @bryanmwolfe

We may earn a commission for purchases using our links. Learn more.