There's no comparison -- the Ecobee4 is the best smart thermostat available today.
Nest is a solid smart thermostat, but the Ecobee4 offers more smart home integrations and a better overall value.
Honeywell's Siri-, Alexa-, and geofencing-enabled Lyric T5 is smart, it works well and it offers a better value than other connected thermostats.
The Thermostat E is almost as smart as Nest's other model -- and all for 80 bucks less.
No other Wi-Fi thermostat available today offers this many smart home partnerships for this low of a price, but you should weigh the importance of the integrations against the MSRP -- many 7-day app-enabled programmable thermostats cost just $100.
The Sensi is a solid option if you're looking for a smart thermostat upgrade that still manages to keep things simple.
The Sensi Touch is a solid smart thermostat, but consider the Ecobee3 Lite or the Nest E if you're looking for similar features and a sleeker look.
While the Ecobee3 doesn't quite match the design and usability of the Nest Learning Thermostat, it is definitely worthy of your consideration.
The Smart Radiator Thermostat from startup Tado works with Apple's HomeKit, Amazon's Alexa and IFTTT.
You don't need a Lennox HVAC system to use its new iComfort E30 Smart Thermostat.
Lux's Kono is a fine thermostat, as long as you control it exclusively from the app or via voice commands.
Honeywell's Wi-Fi Smart Thermostat can compete directly with the Nest Learning Thermostat on features, but it doesn't match the Nest's intuitive design.
Once features like geo-fencing, pattern-learning algorithms and triggers become available, this oddly standard Thermostat could become a strong contender at its price point. For now, though, it's not worth the money.
Carrier's smart thermostat could give Nest some much-needed competition.
Lux's Geo is a fine thermostat, but competing models from Honeywell, Ecobee and Emerson offer more features for roughly the same price.
Get the Honeywell RTHL2310B if you want a basic, affordable thermostat that you can program to suit your schedule.
Emerson's 1F78-151 programmable thermostat is fine, but its competitors offer more in terms of features and design.
The GLAS is a solid smart thermostat, but it isn't a good value if you don't feel strongly about its transparent display and Cortana functionality.