Best Cheap Smart Thermostats Under $100 (and Under $150)

The Short Answer

List prices are from each maker’s own store, checked October 14, 2026. On Amazon on November 7, 2026 (Los Angeles) the X2S was $63.00 and the Amazon Smart Thermostat $79.99, while the Google Nest Thermostat, normally $129.99, was $89.99 (see below). Prices change daily; check the listing. Buying in November? See our Black Friday prices to beat.

You are not giving up savings by buying cheap. ENERGY STAR puts the average for certified smart thermostats at approximately 8% of heating and cooling bills or $50 per year, and that comes from scheduling and away modes, which all of these have. Premium models add room sensors, better heat pump controls and nicer screens.

How we chose: manufacturer specifications and support pages, linked throughout, plus the EPA’s ENERGY STAR certification list. We do not test products in-house.

1. Honeywell Home X2S: Best Overall Under $100

The most complete thermostat at this price. Honeywell lists it at $79.99, ENERGY STAR certified, and compatible with Google Assistant, Amazon Alexa and Apple Home through Matter. It handles heat pumps up to 2 heat/1 cool heat pump with electric backup, with an emergency heat mode.

Skip it if: you have no C wire. Honeywell’s spec is C-wire required (24 VAC). It does not support room sensors.

We may earn a commission if you buy through these links, at no extra cost to you. Products are chosen on published specifications; we do not test them in-house (how we choose).

Honeywell Home X2S Smart Thermostat

ENERGY STAR; Matter (Apple Home, Google, Alexa); heat pump with electric backup; C wire required.

Check price on Amazon

2. Sensi Lite (ST25): Best Without a C Wire

The easiest cheap thermostat for an older home. Sensi says the Lite works on most conventional heating and cooling systems without a c-wire, running on batteries; heat pump systems are the main exception and need one. It is ENERGY STAR certified ($89.99 from Sensi) and its comparison page lists heat pumps up to 2 heat / 1 cool.

Skip it if: you use Apple Home (Sensi lists the Lite as not Apple HomeKit compatible) or want room sensors.

We may earn a commission if you buy through these links, at no extra cost to you. Products are chosen on published specifications; we do not test them in-house (how we choose).

Sensi Lite Smart Thermostat (ST25)

No C wire needed on most systems; ENERGY STAR; Alexa and Google Assistant.

Check price on Amazon

3. Amazon Smart Thermostat: Best for Alexa

Set up and run entirely from the Alexa app. Amazon lists it at $79.99, ENERGY STAR® certified, and compatible with most 24V systems including heat pumps and radiant boilers. It works with Alexa and Ring only: no Google Assistant, Apple Home or Matter.

Skip it if: you have no C wire and don’t want to buy an adapter: Amazon says it may require a C-wire power or power adapter kit (sold separately). Setup trouble? See how to reset an Amazon Smart Thermostat.

We may earn a commission if you buy through these links, at no extra cost to you. Products are chosen on published specifications; we do not test them in-house (how we choose).

Amazon Smart Thermostat

Runs from the Alexa app; ENERGY STAR certified; works with Ring.

Check price on Amazon

Also Under $100: Wyze and Meross

• Wyze Thermostat ($79.98 from Wyze): the only one here with a C-wire adapter in the box (“We’ve included a C-wire adapter in the box”) and support for up to six Wyze room sensors. It supports heat pumps up to 4H/2C and works with Alexa and Google. But it is not ENERGY STAR certified; Wyze’s own answer is “No, not at this time”, which can rule it out of utility rebates.
• Meross Matter Smart Thermostat (MTS300MA, $99.99 list, $66.99 on sale when we checked): Matter certified, so it integrates with Apple Home, Siri, Amazon Alexa, Google Assistant, and SmartThings. Meross says it requires a C wire for power, and it is not on the ENERGY STAR list.

Compatibility at a Glance

Sources: each maker’s product and support pages, linked above. Down to the top three? See Honeywell X2S vs Sensi Lite vs Amazon Smart Thermostat.

What You Give Up Under $100

• Room sensors: the X2S, Sensi Lite and Amazon models don’t support them. If one room is always too hot or cold, look at the ecobee or Nest pairs in ecobee vs Nest.
• Occupancy detection and learning: budget models rely on schedules and phone geofencing rather than sensing who is home.
• Advanced heat pump control: for a heat pump with expensive electric backup, an auxiliary heat lockout is worth paying for. See best thermostat for a heat pump.
• Long software support promises: few budget brands publish one.

Rebates Can Push the Price Lower

Many utilities discount ENERGY STAR certified thermostats, sometimes enough to make one nearly free. Use the ENERGY STAR Rebate Finder with your ZIP code. ENERGY STAR notes that the majority of rebate programs nationwide are residential and do not require participation in demand response programs.

Rebates usually require an ENERGY STAR certified model, which is why the Wyze and Meross picks carry a caveat. We checked certification against the EPA’s certified connected thermostats dataset.

Best Under $150: Worth Stretching Past $100?

Two well-known models sit just above $100 at list price. On Amazon on November 7, 2026 (Los Angeles), the Google Nest Thermostat was $89.99, $40 under its $129.99 list and still under $100, and the ecobee Smart Thermostat Essential was $139.00, about $1 under its $139.99 list.

• Google Nest Thermostat ($129.99 from Google): works without a C wire on most conventional systems, but heat pumps need a C wire or Power Connector. Note that Google’s guaranteed minimum for automatic security updates on this model ran to October 30, 2025; it may still get updates, but there is no longer a promise.
• ecobee Smart Thermostat Essential ($139.99 from ecobee): 3-year warranty and works with ecobee SmartSensors, but needs a C wire or the separately sold Power Extender Kit.
• GE Cync Smart Thermostat ($119.99): ENERGY STAR certified, includes a Power Extender Kit (PEK) for homes without a C wire, and supports wireless sensors.

We may earn a commission if you buy through these links, at no extra cost to you. Products are chosen on published specifications; we do not test them in-house (how we choose).

Google Nest Thermostat

No C wire needed on most conventional systems; heat pumps need a C wire or Power Connector.

Check price on Amazon

ecobee Smart Thermostat Essential

3-year warranty; works with SmartSensors; needs a C wire or the Power Extender Kit.

Check price on Amazon

Before You Buy: Three Checks

1. C wire. With the power off, take the old thermostat off the wall and look for a wire on a C terminal. No C wire? Sensi Lite or Wyze; see thermostats that work without one.
2. System type. Heat pumps, heat-only boilers and multi-stage systems narrow the choice. Note the labels on your existing wires.
3. Rebates. Check the ENERGY STAR Rebate Finder or your utility before buying.

Frequently Asked Questions

What is the best smart thermostat under $100?

For most homes with a C wire, the Honeywell Home X2S: $79.99, ENERGY STAR certified, Matter compatible and heat pump capable. Without a C wire, the Sensi Lite. For an Alexa home, the Amazon Smart Thermostat.

What is the cheapest smart thermostat?

The Wyze Thermostat ($79.98 list) and Meross Matter thermostat (often on sale under $70) are the cheapest, but neither is ENERGY STAR certified, which can rule them out of utility rebates.

Is there a good smart thermostat under $50?

Not at regular prices: the cheapest ENERGY STAR models here list at $79.99. Sales get closer. Amazon had the Honeywell X2S at $63.00 on November 7, 2026, and the Amazon Smart Thermostat has dropped to about $48 to $51 on past Black Fridays (9to5Toys, 2022; Tom's Guide, 2023). A utility store can go lower still: Duke Energy lists the X2S at $9.99 after an instant rebate for its customers.

Will a cheap smart thermostat save as much as an expensive one?

Mostly, yes. Savings come from scheduling and away modes, which budget models have. ENERGY STAR's average for certified models is approximately 8% of heating and cooling bills, or $50 per year.

Do cheap smart thermostats need a C wire?

The Honeywell X2S, Meross and (usually) Amazon models do. The Sensi Lite does not on most conventional systems, and Wyze includes a C-wire adapter.

Which budget smart thermostats work with Apple Home?

The Honeywell Home X2S and Meross MTS300MA, both through Matter. The Sensi Lite, Amazon and Wyze thermostats do not.

Is the Honeywell Home T5 still available?

Honeywell now marks the T5 as discontinued on its own site, though some retailers still have stock. The X2S is its current budget model.

Related Guides

• Best smart thermostat (2026) — all our picks by wiring and budget
• Best smart thermostat without a C-wire — for older wiring
• Best smart thermostat for Alexa — for Echo households
• Ecobee vs Nest — the premium options
• Smart thermostat savings calculator — payback on your numbers

Sources

• Honeywell Home: X2S Smart Thermostat
• Honeywell Home: T5 (discontinued)
• Sensi: Sensi Lite
• Sensi: thermostat comparison
• Sensi: C-wire requirements
• Sensi: Apple HomeKit compatibility
• Sensi: ENERGY STAR
• Amazon (Ring store): Amazon Smart Thermostat
• Wyze: Thermostat
• Wyze: Thermostat tech specs
• Meross: Matter Smart Thermostat MTS300MA
• GE Lighting: Cync Smart Thermostat
• Google Store: Nest Thermostat specs
• Google: Nest device software update policy
• ecobee: Smart Thermostat Essential
• ENERGY STAR: Smart Thermostats FAQ
• ENERGY STAR: Rebate Finder
• EPA: ENERGY STAR certified connected thermostats data (CSV)
• 9to5Toys: Amazon Smart Thermostat at $48 (Black Friday 2022)
• Tom’s Guide: Black Friday smart thermostat deals (2023)
• Duke Energy store: Honeywell Home X2S