Smart Thermostats
Best Smart Thermostat (2026): Top 5 by the Specs
As an Amazon Associate we earn from qualifying purchases. Specs below come from each product's Amazon listing; we do not test products in person.
For a smart thermostat that works without a C wire, the Google Nest Thermostat leads this list. It works without a C wire, adds HVAC monitoring with alerts, and is ENERGY STAR certified. The Honeywell Home model is the runner-up with a customizable color touchscreen, and the Sensi Lite carries a 3-year warranty.
Top picks at a glance
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Best OverallGoogle Nest Thermostat9.8 View on Amazon -
9.5 View on Amazon -
Also GreatAmazon Smart Thermostat9.3 View on Amazon -
Also GreatSensi Lite Smart Thermostat9.2 View on Amazon -
Also Greatecobee Smart Thermostat Essential9.2 View on Amazon
Compare the specs
Ranked on works without a c-wire, room sensor support, works with alexa / google, energy star, phone app control from each listing, plus how many buyers have rated it. A dash (—) means we could not confirm that figure from the listing.
| Pick | Works without a C-wire | Room sensor support | Works with Alexa / Google | ENERGY STAR | Phone app control | Weight | Warranty |
|---|---|---|---|---|---|---|---|
| 1. Google Nest Thermostat | Yes | — | Yes | Yes | Yes | 0.31 lb | 1-year |
| 2. Honeywell Home RTH9585WF1004 Wi-Fi Smart Color Thermostat | — | — | Yes | Yes | Yes | 0.45 lb | 1-year |
| 3. Amazon Smart Thermostat | — | — | Yes | — | Yes | — | — |
| 4. Sensi Lite Smart Thermostat | Yes | — | Yes | Yes | Yes | 0.3 lb | 3-year |
| 5. ecobee Smart Thermostat Essential | — | Yes | Yes | Yes | Yes | 0.2 lb | — |
Google Nest Thermostat
It works without a C wire in most homes, adds HVAC monitoring with alerts, and carries a 1-year warranty.
- Works without a C-wire
- Works with Alexa / Google
- ENERGY STAR
- Phone app control
- 1-year warranty stated
Good for
- Buyers who want a thermostat that works without a C wire in most homes
- Buyers who want HVAC monitoring with alerts about their system
Skip it if
- Your heating-only system needs a C wire or another compatible power accessory
- You want a warranty longer than 1 year
It is ENERGY STAR certified and works with Google Assistant and Matter-certified voice assistants. It creates an energy efficient schedule in the Google Home app and turns itself down when you leave. The box includes mounting screws and a steel plate, and it weighs 0.31 lb.
Honeywell Home RTH9585WF1004 Wi-Fi Smart Color Thermostat
It pairs a customizable color touchscreen with 7-day programming and works with Alexa and Google Home.
- Works with Alexa / Google
- ENERGY STAR
- Phone app control
- 1-year warranty stated
Good for
- Buyers who want a color touchscreen for simple operation
- Buyers with forced air, hot water or steam systems
Skip it if
- You want a thermostat designed to work without a C wire
- You want a warranty longer than 1 year
It has a customizable color touchscreen and flexible programming for your schedule or peak rate pricing. It works with Alexa and Google Home and the mobile app for control from anywhere. It requires a C wire, works with forced air, hot water and steam, and heat pumps with electric backup, and carries a 1-year warranty.
Amazon Smart Thermostat
It is an Alexa thermostat with home, away and sleep schedules and control from the Alexa app.
- Works with Alexa / Google
- Phone app control
Good for
- Buyers who want comfort zones through select Alexa devices
- Buyers who want home, away and sleep schedules
Skip it if
- You want to set it up without using a phone app
- You want voice control outside the Alexa system
It creates home, away and sleep schedules and can adjust heating and cooling through select Alexa devices using temperature readings or presence detection. Control is through the Alexa app when away from home, and the app guides DIY installation. It is made with Honeywell Home Thermostat Technology.
Sensi Lite Smart Thermostat
It works without a C wire in most homes, offers DIY installation with a built-in level, and carries a 3-year warranty.
- Works without a C-wire
- Works with Alexa / Google
- ENERGY STAR
- Phone app control
- 3-year warranty stated
Good for
- Buyers who want DIY installation with a built-in level
- Buyers who want flexible scheduling, geofencing and remote access
Skip it if
- You want a warranty longer than 3 years
- You want a round thermostat for your wall
It is ENERGY STAR certified and works with Alexa, Google Assistant and SmartThings. It offers flexible scheduling, geofencing, remote access and usage reports, plus a built-in level and step-by-step instructions for DIY installation. It works without a C wire in most homes and carries a 3-year warranty.
ecobee Smart Thermostat Essential
It supports a SmartSensor for other rooms, works with Siri, Alexa and Google Assistant, and has a color touchscreen.
- Room sensor support
- Works with Alexa / Google
- ENERGY STAR
- Phone app control
Good for
- Buyers who want temperature readings from other rooms
- Buyers who want a color touchscreen for on-device control
Skip it if
- You want a room sensor included in the box
- You want a rectangular thermostat for your wall
It has a color touchscreen and works with Apple HomeKit, Google Assistant and Alexa. It adjusts to a set schedule and detects indoor humidity. A SmartSensor for other rooms is sold separately, and the box includes a backplate, screws and wire labels.
How to choose
Check C wire needs first
A C wire supplies power to a thermostat. The Nest Thermostat and the Sensi Lite are designed to work without a C wire, but some systems, including heating only, cooling only and heat pump systems, may need a C wire or another compatible power accessory. The Honeywell Home model requires a C wire. Check your system type against the compatibility notes before you buy, so the model you pick matches the wiring already in your wall.
Compare control options
Smart thermostats in this list offer app control, voice control and on-device controls in different mixes. The Nest works with Google Assistant and Matter-certified voice assistants, the Honeywell works with Alexa and Google Home, the Amazon model works through the Alexa app, the Sensi works with Alexa, Google Assistant and SmartThings, and the ecobee works with Apple HomeKit, Google Assistant and Alexa. Pick the mix that matches the app and voice assistant already in your home.
Use schedules and sensors
A schedule lets a thermostat change temperature by time of day, and all five picks here offer programmable schedules. The ecobee supports a SmartSensor that measures temperature in another room, sold separately. Match the schedule style to how your household uses each room through the day.
FAQ
Do I need a C wire for a smart thermostat?
It depends on the model and your system. The Honeywell Home model requires a C wire.
Which smart thermostats work with Alexa?
All five picks work with Alexa in some form. The Amazon model is built around Alexa, the Honeywell works with Alexa and Google Home, and the ecobee also works with Siri and Google Assistant.
Can I install a smart thermostat myself?
The Sensi Lite is made for DIY installation with a built-in level and step-by-step instructions, and the Amazon model guides installation through the Alexa app. The ecobee also offers an easy DIY install. Check system compatibility before you start.
Do these thermostats have room sensors?
The ecobee supports a SmartSensor that measures temperature in another room, sold separately. Use it when one room runs warmer or cooler than the room with the thermostat.
