Google Nest Thermostat 3rd vs 4th Generation Key Differences & Which to Buy

When I first got my hands on the Google Nest Thermostat, it was back in the early days of smart home tech—I remember installing the third-gen model in my old apartment, thinking it was the future. Fast forward a few years, and the fourth generation landed, promising even more. Now, after living with both across different homes and climates—from humid summers in Florida to chilly winters in New York—I\the slimmer profile means less visual clutter, which I appreciate in my minimalist living room. Both have that iconic circular display, but the newer one’s screen is brighter and more responsive—I noticed this when adjusting temps in low light, where the fourth gen shines without glare.

Under the hood, the upgrades become clearer in daily use. The third-gen has decent sensors, but I found it sometimes lagged in detecting room occupancy, leading to minor inefficiencies—like heating an empty kitchen for too long. The fourth gen’s improved motion and temperature sensors are a game-changer; they react faster to movement, saving energy without me lifting a finger. I tested this by leaving the house unexpectedly—the older model took minutes to adjust, while the new one kicked into eco mode almost instantly. That’s not just convenience; it’s real savings on bills over time.

Compatibility can be a headache if you overlook it. Both work with most HVAC systems, but the fourth gen adds broader smart home integration. For instance, in my current setup with Alexa and Google Home, the newer model syncs seamlessly—I can tweak settings via voice while cooking, which the third-gen struggled with occasionally. Software updates play a role too; the fourth gen gets more frequent tweaks, like better scheduling algorithms I’ve seen reduce my energy use by 10-15%. The third-gen isn’t obsolete, but it’s like driving an older car—reliable but missing the latest tech.

Price is where things get practical. The third-gen often sells for under $150 these days, especially on resale sites, while the fourth gen hovers around $200-$250. If you\if simplicity and savings upfront matter more, stick with the third.

Living with both has taught me that tech isn’t just about features—it’s about how it fits into your daily rhythm. The Nest line has come far, and whichever you choose, it’s a step toward a smarter, greener home.