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Environmental and contact sensors comparisons

Leak, contact, and environmental sensors worth installing in a local-first home.

Category guide

Best local leak, contact, and environmental sensors

Comparison tables are useful, but most buyers still want a plainspoken shortlist. The matching guide gives that recommendation layer.

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Strongest overall pick

AirGradient One

AirGradient · HA: excellent · local: excellent

true NDIR CO2 sensor alongside PM2.5, temperature, and humidity, not just VOC estimation

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Best local-control posture

AirGradient One

AirGradient · works offline: yes

Open-source hardware running ESPHome firmware. Fully local, no cloud account required. Can be flashed with custom firmware for complete control.

Why it stands out →
Easiest starting point

AirGradient One

AirGradient · setup: easy

Home Assistant users who want accurate, local indoor air quality data with CO2 readings

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Environmental and contact sensors comparisons — feature comparison by criteria
Criteria AirGradient One AirGradient Open Air Apollo AIR-1 Air Quality Sensor Apollo PLT-1 Plant Sensor Aqara Climate Sensor W100 Aqara Door and Window Sensor P2 Aqara Motion and Light Sensor P2 Aqara TVOC Air Quality Monitor Eve Door & Window Eve Motion Eve Room Eve Weather Heiman Smart Carbon Monoxide Alarm Heiman Water Leak Sensor HomeWizard P1 Meter Shelly BLU Door/Window Shelly BLU Motion Shelly H&T Gen3 Shelly Plus PM Mini Gen3 SONOFF SNZB-02D SONOFF SNZB-03P SONOFF SNZB-04P SONOFF SNZB-06P Zigbee Occupancy Sensor SwitchBot Contact Sensor SwitchBot Leak Detector SwitchBot Meter Pro CO2 Third Reality Water Leak Sensor ThirdReality Door Sensor ThirdReality Garage Door Tilt Sensor ThirdReality Motion Sensor (Matter) ThirdReality Motion Sensor R1 ThirdReality Smart Soil Moisture Sensor ThirdReality Temperature and Humidity Sensor ThirdReality Temperature Sensor Lite ThirdReality Vibration Sensor ThirdReality Zigbee Water Leak Sensor Zooz ZSE11 Q Sensor Zooz ZSE18 Motion Sensor Zooz ZSE42 Water Leak XS Sensor Zooz ZSE43 Tilt/Shock XS Sensor Zooz ZSE44 Temp/Humidity XS Sensor
Local control excellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentgoodgoodexcellentexcellentexcellentexcellentexcellentexcellentgoodgoodgoodexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellentexcellent
Cloud dependency nonenonenonenonenonenonenonenonenonenonenonenonenonenonenonenonenonenonenonenonenonenonenonemediummediummediumnonenonenonenonenonenonenonenonenonenonenonenonenonenonenone
Home Assistant fit excellentexcellentexcellentexcellentgoodgoodgoodgoodgoodgoodgoodgoodgoodgoodexcellentgoodgoodexcellentexcellentexcellentexcellentexcellentgoodgoodgoodgoodgoodgoodgoodgoodgoodgoodgoodgoodgoodgoodexcellentexcellentexcellentexcellentexcellent
Works offline yesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyesyes
Setup difficulty easymoderateeasyeasyeasyeasyeasyeasyeasyeasyeasyeasyeasyeasyeasyeasyeasyeasymoderateeasyeasyeasymoderateeasyeasyeasyeasyeasyeasyeasyeasyeasyeasyeasyeasyeasyeasyeasyeasyeasyeasy
Needs extra hub / controller nononononoyesnoyesnonoyesnonononoyesyesnonoyesyesyesyesnononoyesyesyesnoyesyesyesyesyesyesyesyesyesyesyes
Power / form factor usbusbusbusbbatterybatterybatteryUSB-poweredbatterybatterybatterybatterybatterybatteryusbbatterybatterybatteryhardwiredbatterybatterybatteryUSB-poweredbatterybatterybatterybatterybatterybatterybatterybatterybatterybatterybatterybatterybatterybatterybatterybatterybatterybattery
Protocols wifiwifiwifi, esp-homewifi, esp-homematter, threadzigbeematter, threadzigbeematter, threadmatter, threadthread, matter, bluetoothmatter, threadmatter, threadmatter, threadwifibluetoothbluetoothwifi, mqtt, bluetoothwifi, mqtt, bluetoothzigbeezigbeezigbeezigbeebluetooth, matterbluetooth, matterbluetooth, matterzigbeezigbeezigbeematter, wifizigbeezigbeezigbeezigbeezigbeezigbeez-wavez-wavez-wavez-wavez-wave
Best for Home Assistant users who want accurate, local indoor air quality data with CO2 readingsHome Assistant users in areas affected by wildfire smoke or urban air pollutionHome Assistant users who want comprehensive indoor air quality data for health-conscious automationsHome Assistant users who want to automate plant watering based on actual soil moisture dataHome Assistant users who want cheap, local climate sensors for every roomZigbee-based Home Assistant setups needing reliable door/window sensorsThread-based Home Assistant setups that want simple, reliable motion triggersmonitoring indoor air quality trends alongside temperature and humidityprivacy-conscious buyers who want a no-cloud contact sensorprivacy-conscious buyers who want a no-cloud motion sensor for indoor or sheltered outdoor useprivacy-conscious users who want indoor air quality monitoring with zero cloud involvementHome Assistant users who want local outdoor climate data for automationsusers who want a cross-platform smart CO alarm with local-only operationbudget-conscious users who want Matter leak sensors deployed in multiple locationsDutch and Belgian homeowners who want real-time energy data in Home AssistantHome Assistant users with a Shelly BLU gateway who want cheap, reliable door and window sensorsHome Assistant users building motion-activated lighting or presence-based automations on a budgetHome Assistant users who want a standalone temperature and humidity sensor with a readable displayHome Assistant users who want per-circuit energy monitoring without adding switching capabilityHome Assistant users wanting cheap, reliable temp/humidity monitoringHome Assistant users building motion-activated lighting automations on a budgetHome Assistant users who want to monitor every door and window cheaplybudget presence detection for lights-on-when-occupied automationsSwitchBot ecosystem users who want affordable door and window sensorsplacing under sinks, near water heaters, and in basements for early leak detectionindoor air quality monitoring with Home Assistant automationsbudget water leak monitoring under sinks, water heaters, and washing machinesblanketing your home with door and window sensors on a budgetknowing whether your garage door is open or closed from within Home AssistantHome Assistant users who want Matter-native motion sensing without a Zigbee coordinatorbudget motion-activated lighting automationsautomating garden watering based on actual soil conditionsroom-by-room climate monitoring in a Zigbee Home Assistant setupdeploying cheap temperature sensors in every room for whole-home climate trackingdetecting when the washer or dryer finishes runningscattering cheap leak detectors under sinks, water heaters, and washing machinesrooms where you want motion-activated lighting plus environmental monitoring in one devicehallway or closet light automation where you just need motion detectionunder sinks, water heaters, washing machines, and anywhere pipes can leakgarage door open/close monitoring without wired sensorsmonitoring temperature and humidity in wine cellars, server rooms, crawl spaces, or greenhouses
mid price band

AirGradient One

AirGradient · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Open-source indoor air quality monitor with true NDIR CO2 sensing and ESPHome compatibility.
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premium price band

AirGradient Open Air

AirGradient · local control: excellent · cloud: none

  • Setup: moderate
  • Needs extra hub: no / self-contained
  • Standout: Open-source outdoor air quality monitor with PM particulate tracking and ESPHome integration.
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mid price band

Apollo AIR-1 Air Quality Sensor

Apollo Automation · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: All-in-one air quality sensor covering PM2.5, VOC, CO2, temperature, and humidity, fully local via ESPHome.
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budget price band

Apollo PLT-1 Plant Sensor

Apollo Automation · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Budget ESPHome plant sensor measuring soil moisture, soil temperature, and ambient light, fully local.
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budget price band

Aqara Climate Sensor W100

Aqara · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Budget Thread-native temperature and humidity sensor with full local control.
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budget price band

Aqara Door and Window Sensor P2

Aqara · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Long-battery contact sensing with optional Matter integration paths for broader ecosystem flexibility.
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mid price band

Aqara Motion and Light Sensor P2

Aqara · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Thread-native motion and light sensor with no hub requirement and full local control.
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mid price band

Aqara TVOC Air Quality Monitor

Aqara · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Three-in-one TVOC, temperature, and humidity sensor with an always-on e-ink display.
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mid price band

Eve Door & Window

Eve · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Privacy-first Thread contact sensor with zero cloud dependency.
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mid price band

Eve Motion

Eve · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Privacy-first Thread motion sensor with IPX3 weather resistance for indoor and sheltered outdoor use.
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premium price band

Eve Room

Eve · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: A fully local indoor air quality monitor with an e-ink display, no cloud account, and zero data collection by the vendor.
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mid price band

Eve Weather

Eve · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Outdoor-rated Thread weather sensor with temperature, humidity, and barometric pressure, all fully local.
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mid price band

Heiman Smart Carbon Monoxide Alarm

Heiman · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Among the first Matter over Thread carbon monoxide alarms available, with cross-platform smart home support.
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budget price band

Heiman Water Leak Sensor

Heiman · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Affordable Matter over Thread water leak sensor with cross-platform compatibility.
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mid price band

HomeWizard P1 Meter

HomeWizard · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Reads real-time energy data from Dutch/Belgian P1 smart meters with a fully local API.
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budget price band

Shelly BLU Door/Window

Shelly · local control: good · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Ultra-cheap Bluetooth door/window sensor that works fully local through a Shelly BLU gateway or BLE proxy.
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budget price band

Shelly BLU Motion

Shelly · local control: good · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Budget Bluetooth motion sensor with lux sensing — pair with a BLU gateway for fully local motion-activated automations.
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budget price band

Shelly H&T Gen3

Shelly · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Battery-powered WiFi sensor with an e-ink display that shows temperature and humidity without needing an app.
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budget price band

Shelly Plus PM Mini Gen3

Shelly · local control: excellent · cloud: none

  • Setup: moderate
  • Needs extra hub: no / self-contained
  • Standout: Pure power monitoring in a tiny inline package — tracks watts, voltage, and energy consumption without switching.
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budget price band

SONOFF SNZB-02D

SONOFF · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Integrated LCD with local Zigbee telemetry for both visible and automated climate monitoring.
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budget price band

SONOFF SNZB-03P

SONOFF · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: One of the cheapest Zigbee motion sensors available, making whole-house motion detection affordable.
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budget price band

SONOFF SNZB-04P

SONOFF · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: One of the cheapest Zigbee contact sensors on the market, making it practical to cover every door and window.
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budget price band

SONOFF SNZB-06P Zigbee Occupancy Sensor

SONOFF · local control: excellent · cloud: none

  • Setup: moderate
  • Needs extra hub: yes
  • Standout: Budget mmWave presence detection over Zigbee — detects people sitting still, not just walking by.
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budget price band

SwitchBot Contact Sensor

SwitchBot · local control: good · cloud: medium

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Budget contact sensor with bonus motion detection and a path to Matter via Hub.
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budget price band

SwitchBot Leak Detector

SwitchBot · local control: good · cloud: medium

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Affordable water leak detection with a local Bluetooth connection and Matter upgrade path.
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mid price band

SwitchBot Meter Pro CO2

SwitchBot · local control: good · cloud: medium

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Combined temperature, humidity, and CO2 monitor with e-ink display and Matter support.
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budget price band

Third Reality Water Leak Sensor

Third Reality · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Cheap and reliable Zigbee water leak detection — scatter several around your home for peace of mind.
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budget price band

ThirdReality Door Sensor

ThirdReality · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Low-cost Zigbee contact sensing that scales well across many doors and windows.
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budget price band

ThirdReality Garage Door Tilt Sensor

ThirdReality · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Cheap Zigbee tilt sensor purpose-built for garage door open/close monitoring.
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budget price band

ThirdReality Motion Sensor (Matter)

ThirdReality · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: no / self-contained
  • Standout: Matter-over-WiFi motion sensor. No Zigbee coordinator needed.
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budget price band

ThirdReality Motion Sensor R1

ThirdReality · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Budget Zigbee PIR sensor with dependable trigger speed for lighting automations.
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budget price band

ThirdReality Smart Soil Moisture Sensor

ThirdReality · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Zigbee soil moisture and temperature sensing for smart garden automations.
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budget price band

ThirdReality Temperature and Humidity Sensor

ThirdReality · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Affordable Zigbee temp and humidity sensor with a handy LCD display.
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budget price band

ThirdReality Temperature Sensor Lite

ThirdReality · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: The cheapest way to get Zigbee temperature and humidity data into Home Assistant.
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budget price band

ThirdReality Vibration Sensor

ThirdReality · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Cheap vibration and tilt detection for creative home automations.
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budget price band

ThirdReality Zigbee Water Leak Sensor

Third Reality · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Ultra-affordable Zigbee water leak detection — cheap enough to put one everywhere water could be a problem.
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mid price band

Zooz ZSE11 Q Sensor

Zooz · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Four-in-one Z-Wave sensor: motion, temperature, humidity, and light level in a single compact device.
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budget price band

Zooz ZSE18 Motion Sensor

Zooz · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Compact, affordable Z-Wave PIR motion sensor with magnetic mount and USB-C power option.
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budget price band

Zooz ZSE42 Water Leak XS Sensor

Zooz · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Tiny water leak sensor that fits anywhere pipes run. Pair with a Z-Wave valve actuator for automated shutoff.
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budget price band

Zooz ZSE43 Tilt/Shock XS Sensor

Zooz · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Stick-on tilt and shock sensor for garage doors, cabinets, and gates. No wiring needed.
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budget price band

Zooz ZSE44 Temp/Humidity XS Sensor

Zooz · local control: excellent · cloud: none

  • Setup: easy
  • Needs extra hub: yes
  • Standout: Tiny Z-Wave temperature and humidity sensor. Stick it anywhere for local environmental monitoring.
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