Best Smart Thermostats for 2023: Saving Energy Without Sacrificing Comfort
What Actually Matters in a Smart Thermostat
After testing every major smart thermostat on the market, I can tell you that the marketing claims about energy savings are simultaneously true and misleading. Yes, a smart thermostat can save you 10-15% on heating and cooling costs — the EPA's ENERGY STAR data backs this up. But the savings come almost entirely from one thing: the thermostat knowing when you're away and adjusting accordingly. If you're already disciplined about manually adjusting your thermostat, the savings gap shrinks considerably.
So why buy a smart thermostat? Three reasons that actually matter in practice: automatic home/away detection that works without you thinking about it, remote access when you're traveling and want to check on your home, and room sensors that solve the forever problem of one room being too hot while another is freezing. Everything else — voice control, fancy displays, air quality monitoring — is nice-to-have.
Let me walk through the best options for 2023 and who each one is genuinely built for.
Ecobee Premium: Best Overall Smart Thermostat
What Makes It the Top Pick
The Ecobee Premium is the thermostat I recommend most often because it gets the fundamentals right and then adds meaningful extras. It ships with one SmartSensor for room-specific temperature monitoring, built-in Alexa voice control, and — new to the Premium model — an air quality sensor that monitors VOCs and CO2 levels.
The occupancy detection is genuinely best-in-class. The thermostat itself has a built-in occupancy sensor, and each SmartSensor adds another detection point. After a few days of learning, it accurately knows when your home is empty and adjusts the temperature accordingly. In my testing, the home/away transitions were faster and more reliable than Nest's approach.
The SmartSensor system is what really separates Ecobee from the pack. Place a sensor in your bedroom and tell the thermostat to prioritize that room's temperature at night, then switch to the living room during the day. This is the single most impactful smart thermostat feature for real-world comfort — it effectively solves the "thermostat is in the hallway but I live in the bedroom" problem that plagues most homes.
HVAC Compatibility and Installation
The Ecobee Premium works with most 24V HVAC systems, including multi-stage heating and cooling, heat pumps with auxiliary heat, and dual-fuel systems. It requires a C-wire (common wire) for power, but includes a Power Extender Kit in the box for systems that lack one. In my experience, the Power Extender Kit works reliably — I've installed it in two homes without issues.
Installation takes about 30-45 minutes if you have a C-wire, or up to an hour if you need the Power Extender Kit. The app walks you through wire-by-wire, and it's one of the better guided installation experiences I've seen.
Price: Around $250. Additional SmartSensors run $40 each or $80 for a two-pack.
Works with: Apple HomeKit, Amazon Alexa (built-in), Google Home, SmartThings, Home Assistant, IFTTT.
Google Nest Learning Thermostat: Best Auto-Scheduling
The Learning Algorithm Still Leads
Google's Nest Learning Thermostat (the 3rd generation is still the current model in this line) built its reputation on one promise: it learns your schedule and adjusts automatically. After years of refinement, that promise holds up. The learning algorithm genuinely adapts within the first week or two — it notices that you turn the heat up at 7 AM on weekdays and 9 AM on weekends, and it starts doing it for you.
The Home/Away Assist feature uses a combination of the built-in sensor and your phone's location to determine occupancy. It's effective, though I've noticed it's slower to detect an empty house than Ecobee — sometimes taking 30-60 minutes to switch to "away" mode after everyone leaves. Not a dealbreaker, but it means slightly less energy savings compared to Ecobee's faster transitions.
The Google Ecosystem Factor
If your home runs on Google Home, the Nest Learning Thermostat integrates more deeply than any competitor. You get the full range of Google Assistant routines, seamless control from Nest Hub displays, and energy history in the Google Home app. The Nest's "Rush Hour Rewards" and seasonal energy reports are useful features you won't find elsewhere.
The downside is the flip side of that integration: you need a Google account, and Nest is increasingly locked into Google's ecosystem. HomeKit support does not exist — if you're an Apple household, the Nest Learning Thermostat is a poor fit. The Nest Temperature Sensor (their equivalent of Ecobee's SmartSensor) is available but sold separately at $40 each, and the multi-room functionality isn't as refined as Ecobee's Follow Me approach.
Price: Around $250.
Works with: Google Home, Amazon Alexa. No Apple HomeKit support.
Honeywell Home T9: Best Room Sensor System
A Serious Multi-Room Contender
Honeywell's T9 often gets overlooked, but it has one of the most capable room sensor systems on the market. The T9 Smart Room Sensors detect both temperature and occupancy, and you can set sensor groups for different times of day. The thermostat automatically adjusts heating and cooling based on which rooms are occupied, which is exactly how multi-zone control should work.
The sensor range is impressive — Honeywell claims 200 feet, and in my two-story home, sensors on the second floor communicated reliably with the thermostat on the first floor. Battery life on the sensors has been excellent too, easily lasting over a year on a single CR2450 battery. These sensors are smaller and more discreet than Ecobee's SmartSensors, which is a nice practical advantage when you're placing them on nightstands or bookshelves.
Where the T9 Lags Behind
The T9's app experience is its weakest point. The Honeywell Home app works but feels dated compared to Ecobee and Nest. Scheduling is straightforward enough, but the interface for managing sensor groups and priorities isn't as intuitive as it should be. Geofencing for home/away detection works but isn't as reliable as the competition — it sometimes takes longer to trigger, and I've had occasional false "away" readings when I was home.
That said, the T9 supports most standard HVAC systems and requires a C-wire (no adapter included, which is a notable omission at this price). The hardware itself is well-built with a clean touchscreen display. If Honeywell invested more in their software, the T9 would be a top-two thermostat.
Price: Around $200. Additional sensors are about $40 each.
Works with: Amazon Alexa, Google Home, SmartThings, IFTTT. No Apple HomeKit support.
Ecobee Enhanced: Best Budget Ecobee
Ecobee Quality at a Lower Price
The Ecobee Enhanced is what I recommend when someone likes the Ecobee Premium but can't justify $250. At around $190, the Enhanced drops the built-in Alexa speaker, air quality monitoring, and the metal faceplate, but keeps everything that matters: the same occupancy detection, the same SmartSensor compatibility, and the same excellent scheduling and automation system.
It includes one SmartSensor in the box, just like the Premium. The thermostat uses the same core algorithms for home/away detection and comfort optimization. If you don't care about having a speaker in your thermostat (and honestly, most people have an Echo or HomePod nearby anyway), the Enhanced delivers 90% of the Premium's value.
What You Lose vs. the Premium
Beyond the Alexa speaker and air quality sensor, the Enhanced uses a slightly smaller display and a plastic body instead of the Premium's zinc construction. In daily use, neither of these compromises has bothered me. You still get full HomeKit support, the same app experience, and the same HVAC compatibility.
Price: Around $190 with one SmartSensor.
Works with: Apple HomeKit, Amazon Alexa, Google Home, SmartThings, Home Assistant.
Google Nest Thermostat: Best Budget Google Option
A Solid Entry Point at $130
Not to be confused with the Nest Learning Thermostat, the standard Nest Thermostat (released in 2020) is Google's budget play at around $130. It offers a clean, mirrored display that blends into the wall surprisingly well, basic scheduling, and Home/Away Assist through the Google Home app.
What sets this apart from the cheapest dumb thermostats is the "Savings Finder" feature, which analyzes your usage patterns and suggests schedule adjustments to save energy. It's basically a simplified version of the Learning Thermostat's algorithm — less automatic but still useful. The app will prompt you with suggestions like "You could save by lowering the temperature an hour earlier on weekday nights" and let you accept or ignore them.
The Trade-Offs at This Price
This model does not support Nest Temperature Sensors, so there's no multi-room monitoring. That's the biggest functional gap compared to the models above. The display is a simple mirror-finish design without the Learning Thermostat's classic round display, and programming is done almost entirely through the app rather than on the device itself.
It includes a trim plate to cover the gap if your old thermostat was larger — a thoughtful touch that saves you from patching drywall. HVAC compatibility is broad but not quite as extensive as the Ecobee line: it supports most systems but may not work with some multi-stage setups. Google includes a compatibility checker on their website that I'd recommend running before purchasing. No C-wire adapter is included, but it can draw power without one in some configurations.
Price: Around $130.
Works with: Google Home, Amazon Alexa. No Apple HomeKit.
Aqara Smart Thermostat E1: Best for HomeKit Purists
An Under-the-Radar HomeKit Option
The Aqara Smart Thermostat E1 is the newest entrant on this list and one that flies under the radar compared to the big names. At around $100, it's the most affordable thermostat here that supports Apple HomeKit natively. It also supports Matter, Alexa, and Google Home, making it genuinely cross-platform.
For HomeKit users specifically, the Aqara thermostat works directly with Apple Home without needing any bridge or intermediary device. You can include it in HomeKit automations, scenes, and control it from your Apple Watch. If you've built your smart home around Apple's ecosystem, this is compelling — your thermostat becomes just another device in the Home app alongside your lights, locks, and sensors.
Setting Realistic Expectations
The Aqara E1 is not as feature-rich as the Ecobee or Nest. There's no built-in occupancy detection (though you can pair it with Aqara motion sensors for similar functionality if you're in their ecosystem), no remote temperature sensors of its own, and the learning algorithms are basic. The display is small and utilitarian rather than the attractive screens on the competition.
HVAC compatibility is more limited too — it works with most standard systems but doesn't support multi-stage or heat pump configurations as broadly. Check compatibility carefully before purchasing. That said, for the price, it's a solid thermostat that just happens to also be smart — which is more than enough for many households.
Price: Around $100.
Works with: Apple HomeKit, Matter, Amazon Alexa, Google Home, Aqara Home.
Practical Tips for Any Smart Thermostat
C-Wire: Check Before You Buy
Most smart thermostats require or strongly recommend a C-wire (common wire) for continuous power. Pull your thermostat off the wall and check the wiring before buying anything. If you see a wire connected to the "C" terminal, you're set. If not, you'll either need a thermostat with a power adapter (Ecobee includes one), a C-wire add-on kit (~$15-25 from Amazon), or an electrician to run a new wire. Running the wire is the most reliable long-term solution if you're comfortable with it.
Where to Place Room Sensors
If your thermostat supports room sensors, placement matters more than you might think. Put sensors about 4-5 feet off the ground — roughly chest height. Avoid placing them near windows, exterior doors, kitchens (cooking heat throws off readings), or in direct sunlight. The bedroom and living room are the two most impactful sensor locations for most households. Start with those before adding more.
Realistic Energy Savings
The EPA estimates ENERGY STAR-certified smart thermostats save about 8% on heating and cooling costs, which works out to roughly $50 per year for an average US home. That means most smart thermostats pay for themselves in 2-5 years. The biggest savings come from aggressive away-mode setbacks — if you're gone 8-10 hours a day and the thermostat drops the temperature 5-10 degrees during that time, the savings are real and measurable.
Multi-Zone vs. Single-Zone
If your HVAC system has multiple zones (separate thermostats controlling different areas), you'll need one smart thermostat per zone. Most of the thermostats above support multi-zone setups, but make sure you buy compatible models and check that they coordinate properly. Ecobee and Nest both handle multi-zone homes well, though the setup process is easier with Ecobee.
The Bottom Line
For most people, the Ecobee Premium is the best all-around smart thermostat. It works with every major platform, the SmartSensor system solves real comfort problems, and the occupancy detection is the most reliable available. If you're in the Google ecosystem and don't need HomeKit, the Nest Learning Thermostat is the main competition, with better auto-scheduling but less capable room sensing.
On a budget, the Ecobee Enhanced gives you the same core experience for $60 less, and the Nest Thermostat is a solid basic option at $130. HomeKit-focused buyers should look at the Aqara E1 as an affordable and capable option that won't force you into Google or Amazon's ecosystems.
Whichever you choose, the biggest energy savings come from actually letting the thermostat manage your home/away schedule automatically. Install it, trust the occupancy detection for a couple of weeks, and resist the urge to micromanage. That's where the real payoff lives.