Best Smart Thermostat of 2021
$219.70 at Amazon
Check Price at Amazon
$137.00 at Amazon
$249.00 at Amazon
|Pros||Sleek, easy to install, accurate||Accurate, easy to install, great remote access features||Stylish, accurate||Integrated Alexa voice assistant, easy to install||Inexpensive, includes a C-wire adapter, great remote access features|
|Cons||Expensive, support just refers you to a Nest Pro||Very app reliant, can be harder to set up a schedule||Very expensive, seemed a little buggy to us||Lackluster performance in our accuracy tests, could be more intuitive to use||Not our favorite technical support, could be more accurate|
|Bottom Line||The best of the best, may not be appropriate for all homes||We think this smart thermostat is a fantastic option for anyone looking for a top-tier option for their smart home||This is a solid smart thermostat but is a bit pricey and couldn’t quite topple the top products||This product is a great option for anyone who regularly makes use of smart home voice assistants||We highly recommend this wifi thermostat to anyone shopping on a tight budget and looking for a top-tier product|
|Rating Categories||Nest Learning...||Google Nest...||Johnson Controls...||SmartThermostat...||Wyze Thermostat|
|Ease Of Use (40%)|
|Install & Support (30%)|
|Remote Access (20%)|
|Specs||Nest Learning...||Google Nest...||Johnson Controls...||SmartThermostat...||Wyze Thermostat|
|Colors||Stainless Steel, Copper, White, Black, Mirror Black, Brass, Polished Steel||Snow, Sand, Fog, Charcoal||Transparent screen with silver base||Black||Black, white|
|Battery Backup||Built-in, rechargeable lithium-ion battery||Yes||No||No||No|
|Learning/ Adaptive Controls||Yes - "Nest Sense"||No||No||Yes - adaptive||No|
|Dimensions||Diameter: 3.3 in
Depth: 1.21 in
|Diameter: 3.31 in
Depth: 1.07 in
|Length: 5 in
Width: 5.5 in
Depth: 1 in
|Length: 4.29 in
Width: 4.29 in
Depth: 1.00 in
|Length: 4.7 in
Width: 2.6 in
Depth: 1.3 in
|Works Directly with Alexa/Amazon Echo||Yes||Yes||Yes; Also built-in Cortana||Built-in||Yes|
|Works with Apple HomeKit||No||No||No||Yes||No|
|Model #||T3007ES||G4CVZ||SIO2-10000||SmartThermostat with voice control||WTHERM|
Best Overall WiFi Thermostat
Nest Learning Thermostat
The Nest Learning Thermostat, 3rd Gen. earned the highest score in this review. This sleek and stylish thermostat is jam-packed with features and functionality, all while remaining easy to use and highly accurate. It has a phenomenal display and is available in a handful of colors with different trim plates so you can accent the style of your home. It allows you not only to control your HVAC system whether you are at home or far, far away, but it can interact with many other smart home devices as well, which means you can control your heater or turn on your A/C via your smartwatch or voice command. For those looking to save on their energy bills (and who isn't?), this thermostat has both an occupancy sensor and geofencing to turn down the heat when you leave the house and turn it up when you return.
However, this WiFi thermostat is usually one of the more expensive options out there. If your home has multiple thermostats, count on shelling out a pretty penny to upgrade all of them. Additionally, we experienced mixed results with its learning features, especially if you keep relatively inconsistent schedules week to week. These are minor drawbacks and shouldn't dissuade you too much from considering a Nest, as long as it is within your budget. This thermostat is your best bet if you want the most top of the line, fully-featured smart WiFi thermostat on the market today.
Read review: Nest Learning Thermostat
Best for Alexa/Amazon Smart Homes
Ecobee SmartThermostat with Voice Control
Earning one of the better scores overall, the Ecobee SmartThermostat with Voice Control impressed us with its superior set of smart functions and solid performance across most of our tests. This thermostat doubles as a fully-featured Alexa device and has an upgraded microphone and speaker compared to its previous versions. The SmartThermostat matches the abilities of an Echo or any other Alexa home speaker, allowing you to use calling, messaging, and Drop-In features right on the thermostat. It is also a breeze to install, easy to use, and a great way to add voice control abilities to your smart home right on the wall.
On the downside, setting the schedule on the Ecobee SmartThermostat is not the most user-friendly process we have seen and it offers less customization than its competitors. We also found this product to be somewhat inferior in terms of aesthetic appeal and overall ease of use. These minor flaws become trivial if you are excited about having an Alexa device integrated right into your thermostat.
Read review: Ecobee SmartThermostat with Voice Control
Best Bargain Thermostat
Google Nest Thermostat
If you are looking to spend a lot less than the price tag associated with the top-tier thermostats, then we highly recommend checking out the Google Nest Thermostat. This thermostat has a sleek circular design, is available in a handful of colors, and holds its own against other products that cost almost double. It's very user-friendly and has a full set of remote access features, all while delivering one of the best results in our accuracy test when compared to a lab-grade thermometer. As the name implies, it will also integrate easily with your existing Google smart home system.
However, we did find that the initial setup process can be a little taxing, particularly since you need to use the companion app to configure things like the schedule. This isn't necessarily a bad thing but we think it would have been nice to have the option to edit the schedule both through the app and on the device itself. All in all, this is a fantastic option in our minds for anyone with a Google-based smart home shopping on a budget or anyone else who is trying to find the perfect balance of price tag and performance.
Read review: Google Nest Thermostat
Another Good Budget Buy
Sensi Touch Wi-Fi
If you are looking for a new smart thermostat that can integrate with your existing smart home and won't break the bank, then the Sensi Touch WiFi is a great option. This WiFi thermostat can integrate with Apple HomeKit, Alexa, and Wink. On top of that, the Sensi did quite well across the board in our tests, earning one of the better scores for installation and remote access functionality. It also has a great display that looks fantastic in most homes and clearly indicates what the thermostat is currently doing.
While the initial installation went smoothly, we found it was trickier to do the initial software and scheduling setup. It wasn't too bad, but it took more time than some of the other models. It is also only available in a single color, but it is one of our favorite models if you are looking to save some cash and still want your thermostat to interact with your existing smart home.
Read review: Sensi Touch Wi-Fi
Best Basic Smart Thermostat
Honeywell Wi-Fi 7-Day Programmable
If you are looking for a minimalist thermostat on a budget, you can't go wrong with the Honeywell 7-Day Programmable. This product is a fantastic value and offers reliable remote access to adjust the temperature if you aren't around. This model is accurate, easy to use, and retails for less than half of what the top products go for, making it a great option for homes with multiple thermostats.
This is a standard programmable thermostat with the ability to be remotely adjusted. The appearance and setup process isn't quite as polished as some of the other models, but it gets the job done and is an excellent value. It is a bit harder to operate and install, so expect to be looking through the manual rather than following simple guided tutorials and clear prompts. However, it is by far the best option if you have multiple thermostats and don't want to spend a fortune replacing them.
Read review: Honeywell 7-Day Programmable
Best on a Tight Budget
If you are shopping for a smart thermostat and looking to spend as little as possible, then we think the Wyze Thermostat is definitely a wise purchase. This inexpensive thermostat scored very highly overall, holding its own with other products that cost considerably more. It looks much more like the top-tier products than many of the other budget options, all while being very user-friendly and intuitive to operate. The installation process is fairly easy and you have plenty of remote access options for controlling your HVAC system while you are away.
However, while we did find the overall installation process to be fairly easy, we did notice that the customer support was so-so in our experience. They wouldn't assist with specific questions about our HVAC wiring but there is plenty of written documentation to help you troubleshoot on your home. This product might also not integrate with — or even be compatible — with your existing smart home ecosystem, so it's important to double-check before you buy if you want it to work in tandem with your other smart devices. Despite that, it's hard to find a better option if you are shopping on a tight budget, given that this product delivers a solid performance at a fraction of the price of the top-tier models.
Read review: Wyze Thermostat
Why You Should Trust Us
We bought all of the smart WiFi thermostats in this review at standard prices — we won't ever accept any free or discounted evaluation models. Our testing and review team of Austin Palmer and David Wise have extensive experience comparing and rating smart home products. They have reviewed hundreds of different tech gadgets and home devices, including dozens of smart home specific ones. David also brings his background in heat transfer and thermal fluids engineering as a former mechanical engineer to the design of our tests.
In addition to controlled side-by-side testing, we also installed these products in various homes and offices and have used them for extended periods with all sorts of different HVAC systems. This review has been updated with considerable new information and opinions gleaned from long term real-world use. We looked at the ease of installation and ease of use, how responsive customer support was, the remote access capabilities, and each model's temperature accuracy.
Related: How We Tested WiFi Thermostats
Analysis and Test Results
Our tests were split into four weighted rating metrics, with each thermostat's results discussed below.
Related: Buying Advice for WiFi Thermostats
The Nest Learning Thermostat is on the pricier side but has the performance to back it up. However, this could get especially expensive if your home has multiple heating zones and multiple thermostats. If that is the case, then we think the Google Nest Thermostat is a great choice. It usually costs considerably less than the Learning Thermostat while retaining much of the same functionality. If you are shopping on a tight budget, then you might consider the Honeywell 7-Day Programmable or the Wyze Thermostat. The Honeywell doesn't have anywhere close to the same functionality as our top models, but if you're looking for a bare-bones programmable thermostat that allows for remote access, this is the model for you. The Wyze model costs a fraction of the top models but might not have the same smart home integrations. The Ecobee SmartThermostat isn't an amazingly good deal on its own, but it can be a smart budget choice if you take into account the fact that you won't have to buy an additional Alexa device if you want to add voice control to your smart home.
Ease of Use
Comprising 40% of each model's total score, this is one of the most important metrics when it comes to WiFi thermostats. Ease of use is one of the reasons cited by Energy Star to explain why people do not see the savings they would otherwise expect from an HVAC system controlled by a programmable thermostat. According to them, more than 30% of customers were "unable, unwilling, afraid, uninterested, or otherwise reluctant" to use the scheduling feature, whether it was the default or custom. This will negatively impact any potential energy savings from the device, as a programmable thermostat that is too difficult to program isn't any better than a single-temperature model.
To test the ease of use, we looked at the initial setup, setting the time and date, the ease of setting up a schedule, adjusting the temperature, and the difficulty of utilizing the advanced features. Comparing the WiFi thermostats side-by-side, we ranked them on each of the above attributes and assigned scores based on their performance.
The Nest Learning Thermostat lead the group in this set of tests, earning top marks. This thermostat guides you through the entire setup process with questions and prompts, but we found it to be a bit of a hassle to set a schedule on the Nest Learning Thermostat, mainly due to its single-button and wheel interface. This interface also makes it pretty annoying to enter a complicated network password.
However, it still is fairly intuitive to scroll through the menus for additional options and exceptionally easy to adjust the temperature by rotating the dial. This will also override the schedule and hold the temperature you set manually until the next change in the schedule. The display on this product is particularly vibrant and displays information very clearly, even when viewed from across the room.
Next, the Johnson Controls Glas, the Ecobee SmartThermostat, and the Wyze Thermostat follow in our ease of use metric. The setup process on the Ecobee SmartThermostat is almost as easy as the Nest Learning Thermostat, again utilizing a series of guided prompts to walk you through the various tasks.
It also is very easy to scroll through the different menus and set things like the date and time. However, we aren't huge fans of the scheduling system on the Ecobee SmartThermostat. You set different comfort zones for each block of time and then separately set the temperature for each comfort zone, which just doesn't seem as user-friendly and is more restrictive than setting a temperature for each chunk of time directly. We don't think this model's display conveys information quite as clearly as the top models, and the touchscreen slider that adjusts the current temperature isn't our favorite interface, keeping this thermostat out of the top tier when it comes to ease of use.
The GLAS by Johnson Controls comes with a step-by-step first-time process that is simple and straightforward to follow. It includes prompts that lead you through every detail, making it exceptionally easy to set up.
This thermostat will also automatically set the date and time when connected to WiFi, though you will need to manually set the time zone. There aren't many other settings to adjust, but they are fairly intuitive to find and alter without sifting through submenus. It's relatively easy to adjust the temperature setpoint by selecting it and then using the up or down arrows on the touchscreen to change it. The display's information is very clean and easy to read — even from a fair distance — and you have the option to adjust the brightness of the screen.
However, the screen almost instantly picks up fingerprints and requires semi-regular cleanings. We aren't huge fans of the scheduling function because you don't have the option to set a specific temperature for different times — you can only set "Home" and "Away" temperatures and then what times you would like it to switch between these settings.
This model's standout features include the built-in air quality measurement, Alexa voice control compatibility, and built-in Cortana voice control.
We did have to dive into the instruction manual to start the setup process on the Wyze Thermostat since it lacks guided prompts when you first plug it in but after that, the initial configuration was quite easy. You do need to use the app to set the schedule but it's very easy to access other settings on the thermostat. The date and time are automatically set and you can even set maintenance reminders that not only alert you when it's time to change the filters but also allows you to record the usage and size, as well as % usage and expected lifespan.
Information is clear and easy to read on the display of the Wyze Thermostat and the mechanical dial makes it easy to adjust the temperature if you want to deviate from the set schedule.
The Sensi Touch WiFi, the Honeywell 7-Day Programmable, the Google Nest Thermostat, and the Ecobee3 Lite all are about average in our minds when it comes to ease of use, earning them a score in the middle of the group.
The Sensi Touch WiFi is a little more difficult to schedule than some of the other models in the pack. It only offers a limited set of scheduling abilities on the device itself, and one of its odd quirks is that the WiFi needs to be turned off to do it. This model at least informs you that this is necessary. We were forced to figure that out on our own with the original Sensi. The same goes for setting the time and date.
This thermostat has a decent suite of advanced features and functions that can be adjusted, including "Safe Mode", where the thermostat will ignore rapid commands. This makes it a great option for families with children that are prone to fiddling with the thermostat.
This model makes it easy enough to adjust the current temperature, using the touch screen instead of buttons. The current temperature is displayed prominently, with the set temperature shown in smaller text off to the side. One drawback is that you cannot adjust the screen brightness.
The Honeywell 7-Day Programmable uses an interface similar to traditional thermostats. Programming requires a deep dive into the manual to figure out how to configure the WiFi. It is very easy to adjust and hold the current temperature using the arrow keys, but it can be somewhat difficult to access the menus for advanced settings. It takes a combination of button presses — think classic video game cheat codes — to get to these menus, which is a handy way of preventing unauthorized access. However, we found that we had to consult the manual to look up the appropriate code every time we needed to adjust something.
The Ecobee3 Lite also relies on a series of guided prompts to complete the initial setup process, but we didn't find them to be as intuitive or informative as other models. The rest of the settings are pretty straightforward, but we did find that adjusting the current temperature and setting a schedule are both somehow far less user-friendly than the top models. The display is also a little harder to see and understand.
The Ecobee3 Lite offers some of the best options when it comes to altering your schedule, allowing you to hold the temperature indefinitely, for a set amount of time, or until the next change in the schedule. The Nest Learning Thermostat, in contrast, will only hold until the next slot in the schedule. There are a few other useful features that were scattered around to make them easier to use.
The Google Nest Thermostat is just about as clear and easy to read as the Nest Learning Thermostat. The background changes color depending on what your HVAC system is doing and it shows the estimated time to reach the target temperature. It also offers a ton of versatility when it comes to deviating from the set schedule, allowing you to set the time when the hold will end or you can quickly change to one of your preset temperature zones, like "Sleep" or "Eco".
We think the touch interface on the side is alright, though we did find that we prefer the tactile feel of the mechanical models. You also do need to use your phone to set up the initial schedule.
We found it substantially more confusing to set up the Sensi WiFi Programmable — both with the initial setup and creating a schedule. It was bad enough that we originally assumed that it was not possible to set up without the app. However, we eventually determined that it is possible to set the schedule without the app, but only when the device is not connected to WiFi. Our struggles primarily occurred when using the device itself. The setup was markedly easier if done exclusively on the mobile app. This confusion and discrepancy earned the Sensi WiFi Programmable the lowest score of the entire group in this metric, a 4 out of 10 on our tests.
Install & Support
Install & Support comprises 30% of the total score for each WiFi thermostat. Although all of these products are designed with a DIY installer in mind, the installation process can become more complicated if you have an older home or a particularly uncommon HVAC system. If that's the case, then you may need to have a professional install your new thermostat. In addition to the install, we tested each company's customer support, putting in a request and evaluating the responses, and rating the supplied documentation.
To rate the quality of the customer support, we sent the following email anonymously to each manufacturer, then awarded points based on the timeliness and quality of the response we received:
"Hi there. I am trying to install my new [thermostat model]. I just moved into a new home and the previous owners took out their thermostat and left these wires hanging out (blue, yellow, red, green). I have no clue as to which wire goes where. I only have a heating system, which seems to be electric. It gets very cold at night and I would love to be toasty warm. Thanks in advance for the help!"
With this picture attached:
To compare the ease of installation, we hooked each thermostat up to our custom testing board and also installed them in our office. We created our testing setup, mimicking a single-stage heating, single-stage cooling, and auxiliary fan HVAC system, which allowed us to easily compare the different products side by side. Our office has a single-stage heating and auxiliary fan system (a fairly typical configuration).
The Nest Learning Thermostat, the Google Nest Thermostat, the Ecobee3 Lite, and the Ecobee SmartThermostat all tied for the top spot in this rating category.The Nest customer support wasn't exceptionally helpful for a DIY install, repeatedly referring us to a Nest Professional instead of walking us through the steps to resolve our issue. However, Nest does an exceedingly good job in providing adequate, step-by-step documentation and helpful videos online. We think it is one of the few products where the help page is actually helpful when it comes to solving more complicated problems.
We particularly liked that there is a built-in bubble level on the base plates of both the Nest Learning Thermostat and the Google Nest Thermostat to make the installation process even easier.
Our experience with the support team from Ecobee was the polar opposite. They walked us through every step of the process, instructing us on which wire went where in a series of emails. The Ecobee Lite and Ecobee SmartThermostat also come with extensive documentation — both in the written guide and a companion app — that will help you through the physical install. Additional instructional videos are available online if you get lost. Both feature an integrated level in the trim plate to ensure that it gets hung up straight.
Following these top two thermostats, the Glas, the Wyze Thermostat, and the pair of thermostats from Sensi come next in our ranking of ease of installation. GLAS's customer support was very helpful in resolving our issues, particularly with the GLAS-specific smart functions. Sensi's team wasn't quite as helpful and usually required a follow-up email to resolve an issue fully.
However, we found that the Sensi and the Sensi Touch WiFi are some of the easiest models to install. They came with a built-in level on the base plate, which was amazingly helpful. The company also provides extensive documentation if you find yourself stuck.
Lacking a built-in level, the GLAS is a little bit more difficult to install. It also has a very small base to cover up imperfections on your wall, so if you had a larger thermostat installed previously, you might have to do some drywall repair or touch-up painting. You can use the included white trim plate if you prefer that look.
While we did find the Wyze Thermostat's support team to be a bit reticent when it came to advising us on specific HVAC wiring issues, they do provide a plethora of helpful documentation to help figure out any problems on your own. The slides even have extra videos to walk you through the steps if you need more assistance. The Wifi setup was very easy and the backplate also has an integrated level, though we did think the text can be a bit hard to read on the quick-connect terminals.
Finishing out the group, the Honeywell 7-Day Programmable merited a 5 out of 10. Customer service was fine (though not overly helpful), and the installation process took slightly longer than the others. Installation of these products essentially breaks down into checking if your system is compatible through the online documentation or contacting the manufacturers' customer service department and then completing the actual install. This should be a relatively hassle-free process for the vast majority of people who have fairly standard HVAC systems in their homes. For those with a unique system, special attention must be paid, and at the very least, you should consult with the manufacturers before purchasing to ensure compatibility.
Remote access is one of the cornerstones of WiFi thermostats and merits 20% of each model's total score. This rating metric was split into three major components: adjusting the temperature through the smartphone app, setting and editing the schedule remotely, and the ease of adjusting other, more advanced settings through the remote interface. Although we originally thought this would be a much more substantial part of the scores, we found that most of the thermostats performed exceptionally well in this category.
We do think that the Wyze Thermostat takes a slight lead when it comes to remote access abilities, just narrowly edging out its competitors for the top spot. This thermostat has a smartphone app that is very easy and straightforward to use. There are a few more settings than what you have access to on the device itself but not many, making it much more intuitive to use than most of the other brands in our minds.
The scheduling is very simple, with a preset one to start with that you can change at any time. Our only complaint is the touch dial can be a little finicky — at least on our test phone — making it easy to overshoot your target temperature. It has a fully automatic mode as well, where you just set the target temperature and it will decide if it's necessary to run heating or cooling to achieve it.
The Honeywell 7-Day Programmable, the Google Nest Thermostat, the Sensi Touch, and the Sensi Programmable all followed with their excellent remote access capabilities. The Honeywell 7-Day Programmable performed extraordinarily well, as it was substantially more user-friendly than other products when it came to setting up a schedule remotely. The pair of Sensi thermostats also offered an easy setup, and an incredible amount of customization — allowing you to set the temperature in as little as 15-minute increments! There is also a calendar view where you can see the entire week and all the temperatures you have set.
While the name might suggest that the Google Nest Thermostat and the Nest Learning Thermostat use the same app, they actually don't. The Google Nest Thermostat is controlled through the Google Home app while the Nest Learning Thermostat can be controlled by both, with all functionality besides basic temperature adjustment for the Nest Learning Thermostat pushed to the Nest app. We found it considerably easier to set the schedule with the preset options in the Google Home app than the Nest app and, on the whole, we found that app more intuitive and easy to use.
The Nest Learning Thermostat, Johnson Controls GLAS, Ecobee SmartThermostat, and the Ecobee3 Lite all came next with their above-average remote interfaces.
Like the Sensi, the Nest app provides an attractive amount of customization, but the interface felt substantially less intuitive. However, when it came to setting the schedule, we found the Nest app to be a bit more labor-intensive and convoluted than we would have liked.
The Ecobee apps essentially mirror the display on the actual thermostat, which means that it is substantially less user-friendly to set a schedule or adjust the temperature than many other models. However, we did find that we usually preferred to use the app to set the schedule or change the temperature because the adjustment slider has a larger range per screen on your phone than the thermostat.
Unfortunately, you are locked out of adjusting any of the advanced settings remotely with the Ecobee.
The GLAS app also mirrors the device in terms of layout, but you get the added benefit of not smudging or leaving fingerprints on the display of the GLAS. This thermostat shows smudges or fingerprints much more than the others, and we found ourselves almost perpetually cleaning it, so using the app was a welcome reprieve from having to wipe it down. The scheduling system doesn't change on the remote app — even though we wished it did — as setting the temperature for home or away and then scheduling times seems much more difficult than just designating a temperature for each chunk of time.
We immediately noticed discrepancies in the measured ambient temperatures when testing multiple models side-by-side, with some even showing a discrepancy as large as two degrees. While these differences may be tiny, accuracy is an incredibly important aspect of these products. The most energy-conscious among us may choose the temperature setting based on the Government EnergySaver guidelines to maximize energy savings. An inaccurate thermostat can be a severe detriment to your wallet and leave you guessing if your home and away temperatures are set anywhere close to where they should be. Overall, our accuracy tests account for 10% of each product's score.
To test this, we compared each thermostat against a lab-grade thermometer multiple times after allowing the temperature to settle. All of our measurements were taken in Fahrenheit.
The Nest Learning Thermostat, the Google Nest Thermostat, and the Honeywell 7-Day all thoroughly impressed us in this regard, earning excellent marks. Both the Nest Learning Thermostat and the Google Nest Thermostat were typically within 0.5 degrees of our control thermometer, rounding their measurement to the nearest whole degree. The Honeywell 7-day matched this performance, maintaining approximately the same margin of error.
The GLAS closely It was close to the top products but usually showed a slightly larger discrepancy than the Honeywell 7-Day and the Nest models — closer to a full degree off.
Both Sensi models followed, usually differing from our control by roughly a degree or a little more. The Wyze Thermostat had just a bit larger of a margin of error in our tests but we do like that it gives you the option to calibrate the temperature if you want.
The Ecobee SmartThermostat and the Ecobee3 were anywhere from half a degree to two degrees off, but these thermostats also give you an option to calibrate the temperature if it is consistently off by the same amount.
Finding the perfect smart thermostat that matches not only your needs and budget but also your current heating and cooling system requirements can be a difficult task. We hope our side-by-side comparison and analysis has been helpful in your search for a new thermostat, regardless of whether you're looking for a top-tier model with all the smart features and functions imaginable or a simple budget option that only allows for remote access. Finally, we want to remind you that you shouldn't hesitate to enlist a professional installer for these products if you aren't comfortable with a DIY installation, as there are some risks and you could inadvertently damage the thermostat or other components of your HVAC system — particularly with older homes or uncommon heating and cooling systems.
— David Wise and Austin Palmer