SONOFF SNZB-03P Zigbee Motion Sensor Review: Fast, Cheap and Reliable, With a Basic Light Sensor and a Home Assistant Quirk
This budget Zigbee sensor pairs with almost any Zigbee hub, detects motion near-instantly and lasts about three years on a battery, but its light sensor only reports dim/bright, and in Home Assistant the 'motion' entity can get stuck (use 'occupancy' instead).
The SONOFF SNZB-03P is a low-cost Zigbee motion sensor that owners rate well (a 4.3-star average). Its appeal is strong value plus fast, reliable performance: detection is near-instant (often sub-second in Home Assistant via ZHA), it pairs easily with a wide range of Zigbee hubs, not just the SONOFF Bridge, but also SmartThings, Hubitat, and Home Assistant via Zigbee2MQTT/ConBee, and setup takes about five minutes. It's compact and discreet, includes a magnetic base plus screws and tape for flexible mounting, ships with batteries, and lasts around three years, with the battery level visible in Home Assistant. It also has a built-in ambient-light sensor for dark-only lighting automations, and you can set the no-motion timeout. It works with Alexa, Google Home and Home Assistant (no Apple HomeKit or Matter). The caveats are specific but worth knowing. The light sensor only reports 'dim' or 'bright', not a numerical lux value, so you can't fine-tune light-based automations. In Home Assistant, several owners report the 'motion' entity getting stuck on or off (you have to rely on the 'occupancy' entity, which works, and SONOFF support was unhelpful about the bug). Some units occasionally drop off the Zigbee network, range is limited (about 6m, so mind placement in large rooms), it requires a Zigbee hub (the SONOFF Bridge isn't included), and getting to the battery/removing the tab is fiddly without instructions. For a cheap, responsive Zigbee sensor, especially in a Home Assistant or SmartThings setup, it's a strong value pick.
- Budget Zigbee motion detection
- Home Assistant, SmartThings or Hubitat setups
- Fast, responsive lighting automations
- Dark-only triggers (basic light sensor)
Pros
- Cheap with good build quality and long (~3-year) battery life
- Fast, near-instant detection; pairs with many Zigbee hubs (not just SONOFF)
- Flexible magnetic/screw/tape mounting; batteries included; battery level visible in HA
- Built-in ambient-light sensor for dark-only automations; adjustable timeout
Cons
- Light sensor only reports 'dim'/'bright' (no numerical lux value)
- In Home Assistant the 'motion' entity can get stuck (use 'occupancy')
- Occasional Zigbee network drops; limited ~6m range
- Requires a Zigbee hub (not included); no HomeKit or Matter; fiddly battery access
Who is the SONOFF SNZB-03P for?
This is an inexpensive Zigbee 3.0 motion sensor with a basic ambient-light sensor, covering about 110 degrees to 6m/20ft, running roughly 3 years on a CR2477 battery. It requires a Zigbee hub, but works with many (SONOFF Bridge, SmartThings, Hubitat, Home Assistant via ZHA or Zigbee2MQTT), and integrates with Alexa, Google Home and Home Assistant (no Apple HomeKit or Matter). It's ideal for anyone with a Zigbee setup who wants cheap, fast, reliable motion detection for lighting and automations. It's less ideal if you need HomeKit/Matter, precise lux-based automations, or long range in large spaces.
What buyers love
Value and speed lead. Owners repeatedly call it a great sensor at a low price, and detection is fast, often sub-second in Home Assistant via ZHA, and reliable for daily use (one runs it many times a day in a pantry flawlessly). It pairs easily with a wide range of Zigbee hubs, not just SONOFF's Bridge but also SmartThings, Hubitat and Home Assistant (ZHA or Zigbee2MQTT), with setup taking around five minutes. Mounting is flexible thanks to a magnetic base plus screws and tape (great for angling), it comes with batteries, and battery life is long (about three years) and visible in Home Assistant. The built-in ambient-light sensor lets you trigger lights only when it's dark, and you can configure the no-motion timeout. Compact and discreet, it's a favorite budget choice, several owners bought multiples for the whole house.
What to know before you buy
A few limitations. The ambient-light sensor only reports 'dim' or 'bright' rather than a numerical lux value, so you can't finely tune light-based automations (the 'dim' threshold may not match what you want). In Home Assistant, several owners report the device's 'motion' entity getting stuck in an on or off state and needing a manual reset, while the separate 'occupancy' entity works correctly, so you rely on 'occupancy' for automations, and SONOFF support was described as unhelpful about this bug. Some units occasionally fall off the Zigbee network, range is limited (around 6m, so placement matters in larger rooms), and it requires a Zigbee hub that isn't included (a barrier if you don't already have a coordinator). Getting to the battery and removing the pull tab is also fiddly with no clear instructions (owners suggest a quick YouTube search). Note there's no Apple HomeKit or Matter support.
Is the SONOFF SNZB-03P worth it?
For a Zigbee household, yes. It's cheap, fast, reliable and easy to pair with almost any Zigbee hub, with long battery life and flexible mounting, which is why it averages 4.3 stars. Just go in aware of the caveats: the light sensor only reports dim/bright (no lux value), the Home Assistant 'motion' entity can stick (use 'occupancy'), occasional network drops, limited range, and no HomeKit/Matter, plus you'll need a Zigbee hub. If you have (or will add) a Zigbee coordinator and want a responsive, low-cost motion sensor for lighting and automations, it's an excellent value; if you need precise light-level control or HomeKit/Matter, look elsewhere.
Frequently asked questions
Do I need the SONOFF Zigbee Bridge?
You need a Zigbee hub, but not specifically SONOFF's. Owners pair it with SmartThings, Hubitat, and Home Assistant via ZHA or Zigbee2MQTT (ConBee, etc.), as well as the SONOFF Bridge. It's not included, so you'll need some Zigbee coordinator. It works with Alexa, Google Home and Home Assistant, but not HomeKit or Matter.
How good is the built-in light sensor?
It's useful but basic. It reports only 'dim' or 'bright' rather than a numerical lux value, so you can trigger lights only when it's dark, but you can't finely tune the threshold. Owners appreciate having it, but wish it reported an exact value for more flexible automations.
Is there a Home Assistant bug I should know about?
Yes. Several owners report the device's 'motion' entity getting stuck in an on or off state and needing a manual reset, while the separate 'occupancy' entity works reliably. The workaround is to base your automations on 'occupancy.' SONOFF support was described as unhelpful about this issue.
How fast and reliable is the detection?
Very fast, often sub-second in Home Assistant via ZHA, and reliable for daily use. Some owners do report the sensor occasionally dropping off the Zigbee network, and range is limited (about 6m), so mind placement in larger rooms, but overall responsiveness is a strong point.
How long does the battery last?
About three years on the included CR2477 battery, and in Home Assistant you can monitor the battery level. Combined with fast detection and easy pairing, the long battery life makes it a low-maintenance, high-value sensor, provided you already have a Zigbee hub.










