What are the best smart thermostats for small homes or apartments?

Amazon Smart Thermostat (S6ED3R) is an ENERGY STAR certified, Wi-Fi thermostat designed for most 24V HVAC systems. It uses Alexa for scheduling/voice control via the Alexa app and Alexa-enabled devices, and supports user device based geofencing. It includes humidity sensing and standby power of 0.89 W.

ecobee Smart Thermostat Premium combines scheduling automation with built-in occupancy sensing and home/away adjustments to save energy automatically. It also supports voice control (Alexa Built-in or Siri when enabled via an Apple Home hub) and provides smart home integrations like Apple HomeKit, Amazon Alexa, Google Assistant, SmartThings, and IFTTT. It's a good fit for people who want hands-free control plus automatic comfort management in small homes or apartments.

The Emerson Sensi ST55 is an ENERGY STAR-certified smart thermostat with Wi-Fi, remote app control, flexible seven-day scheduling, usage reports, and geofencing. It suits people who want straightforward smart control and broad HVAC compatibility without a touchscreen or behavior-learning features.

Sensibo Air is a smart AC controller for remote-controlled air conditioners and heat pumps, including mini-splits, window units, portable units, and central systems. It adds app control, geofencing, scheduling, temperature and humidity sensing, Climate React automation, and voice control, making it well suited to apartment dwellers who want convenient comfort and lower energy use.

The Mysa Smart Thermostat is a Wi-Fi thermostat for high-voltage electric heating systems, including baseboard, fan-forced in-wall, self-contained hydronic baseboard, and in-ceiling radiant heaters. It offers app control, scheduling, geofencing, energy reports, zoning, and integration with major smart-home platforms, making it well suited to homeowners who want room-by-room control and energy savings.

The ecobee Smart Thermostat Enhanced uses occupancy sensing, scheduling, humidity adjustment, and energy-saving recommendations to help maintain comfort automatically. It suits households wanting broad smart-home integration and remote control through a smartphone or smartwatch.

The Honeywell Home T5 is an ENERGY STAR certified smart thermostat with flexible 7-day scheduling, geofencing, smartphone control, energy reports, and alerts. It suits apartments and small homes with compatible 24 VAC HVAC systems and a C-wire.

The Copeland Sensi ST55 is an ENERGY STAR certified Wi-Fi thermostat with remote control, flexible 7-day scheduling, usage reports, smart alerts, and geofencing. It suits apartments and small homes that need straightforward HVAC control and broad smart-home integration without requiring a c-wire for most systems.

The Honeywell Home T9 is an ENERGY STAR certified smart thermostat with Wi-Fi, 7-day scheduling, geofencing, and a Smart Room Sensor that can prioritize occupied rooms. It suits homes with compatible 24V HVAC systems, especially users who want room-by-room comfort and voice control.