SONOFF SNZB-04P

Quick verdict

A dead-simple Zigbee contact sensor at a price that lets you put one on every door and window in the house. The P version brings improved range and battery over the original. Pair with a Zigbee coordinator, add to Home Assistant, and automate away — lights on when the front door opens, alerts when the garage is left open, that kind of thing.

Standout: One of the cheapest Zigbee contact sensors on the market, making it practical to cover every door and window.

Last checked: 2026-03-23

Compatibility snapshot

Why it stands out

• among the cheapest Zigbee contact sensors you can find
• compact enough to fit on most doors and windows without standing out
• improved battery life and Zigbee range over the older SNZB-04

Reasons to hesitate

• requires a Zigbee coordinator — no standalone use
• no built-in temperature sensor (some competitors include one)
• no native voice assistant support without Home Assistant bridging

Best for

• Home Assistant users who want to monitor every door and window cheaply
• triggering automations when doors open — lights, alerts, HVAC adjustments

Avoid if

• you do not have a Zigbee coordinator
• you want a contact sensor that works directly with Alexa or Google Home

Privacy and local-control notes

Pure Zigbee device with no cloud component. Fully local when paired with a Zigbee coordinator.

Home Assistant support: supported · integration path: zigbee2mqtt / ZHA.

Buying reality check

Price notes: Rock-bottom pricing for a Zigbee contact sensor. The P version replaces the original SNZB-04 with better range and battery life.

Compare side by side: see sensor comparisons →