Smart Thermostats Compared Across Every Protocol
All 20 thermostats we rank, from 3 review pages, in one table. Filter by the smart home system you use or by protocol, then open a product to see its full review.
Smart Thermostats by protocol
How do these protocols differ? Show the pros and cons
Pros
- Sub-GHz radio doesn't compete with Wi-Fi or Zigbee on 2.4 GHz
- Lower frequency gets through walls and floors better than 2.4 GHz
- Mandatory certification, so devices from different brands work together
- Every mains-powered device repeats the signal and extends the mesh
- S2 security is required on newer certified devices
- Z-Wave Long Range reaches outbuildings and supports up to 4,000 devices
Cons
- Needs a hub or USB controller; there's no phone-only setup
- Devices usually cost more than Zigbee or Wi-Fi equivalents
- Frequencies are regional, so a US device won't work on an EU controller
- Low bandwidth rules out cameras and anything streaming
- Classic mesh tops out at 232 devices and 4 hops
Our take: The safest pick for a hub-based setup that has to keep working for years. Every certified device talks to every certified controller, and its band stays out of Wi-Fi's way.
Pros
- No hub; it joins the network you already have
- Enough bandwidth for live video and audio
- Widest choice of brands and the lowest entry prices
- Setup is usually an app and a few taps
Cons
- Power hungry; battery Wi-Fi sensors need frequent charging
- Many devices only support 2.4 GHz, which complicates setup on mixed-band routers
- Dozens of devices can overload consumer routers
- Many products depend on the maker's cloud and stop working if it shuts down
- No mesh between devices; range is whatever your router covers
Our take: Right for cameras, doorbells, and anything plugged in. Wrong for battery sensors, and a few dozen devices can overload a cheap router.
Pros
- One device works with Apple Home, Google Home, Alexa, SmartThings, and Home Assistant
- Multi-admin lets several ecosystems control the same device at once
- Local control by design, no cloud needed for day-to-day use
- Setup is a QR code scan in whichever app you prefer
Cons
- Only device types in the current spec are supported, so advanced features often stay in the maker's app
- Each platform exposes a different slice of what a device can do
- Pairing and multi-admin bugs are still common
- Matter over Thread devices still need a Thread border router
Our take: Buy Matter devices when you can, because they keep your options open. Check that the features you need are in the spec before you buy.
All thermostats
All protocols
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Scores come from each product's protocol page, where it was ranked against devices on the same protocol. Red rows are the picks we tell you to avoid. Prices captured from Amazon between 2026-10-04 and 2026-10-04.