Google Nest Protect (Wired) vs X-Sense Wi-Fi Smoke Alarm

The Google Nest Protect (Wired) is better overall because it detects both smoke and carbon monoxide, adds occupancy, temperature, humidity, light and motion sensing, tests itself, and carries a higher owner rating. The X-Sense Wi-Fi Smoke Alarm is smoke-only but wins on warranty length.

Carbon monoxide coverage and smarts. The Google Nest Protect (Wired) senses both smoke and CO and adds self-test, a pathlight and Google Home and Home Assistant support, while the X-Sense Wi-Fi Smoke Alarm detects smoke only and simply pushes alerts through its own app.

The X-Sense Wi-Fi Smoke Alarm leads here, with a 5-year warranty and a CR123A cell rated for 10 years. The Google Nest Protect (Wired) runs on mains power with a 3 AA backup and carries a 2-year warranty, so it depends on your wiring rather than a long-life cell.

Only the Google Nest Protect (Wired) does; it combines smoke and CO sensing in one unit. The X-Sense Wi-Fi Smoke Alarm has no CO sensor, so you would need a separate carbon monoxide detector alongside it.

Buy the Google Nest Protect (Wired) if you have alarm wiring and want combined smoke and carbon monoxide detection with spoken early warnings, phone alerts, self-testing and a pathlight, ideally in a Google or Nest household.

Buy the X-Sense Wi-Fi Smoke Alarm if you only need smoke protection, want a long battery rating and a 5-year warranty at a lower price, and are happy to add a separate CO detector and skip smart home integration.