AirGradient is a Thailand-based maker of open-source air quality monitors, led by founder Achim Haug. The ONE is an indoor monitor and the Open Air is an outdoor one. Both come assembled or as DIY kits, measure particles, CO2, VOCs, NOx, temperature and humidity, and can be read locally or through the AirGradient dashboard.
AirGradient monitors connect over 2.4 GHz Wi-Fi and serve readings through a local API, so they work without the cloud. Uploading to the AirGradient dashboard is optional. Home Assistant has a built-in integration, and Homey, ESPHome, openHAB and MQTT routes also exist. We found no voice assistant or Matter support.
That suits people who want local, scriptable air quality data in Home Assistant or Homey and value repairable, open hardware and firmware. It is weaker for anyone who wants Alexa, Google Home or Apple Home control, or Matter, since none was found.
Connection
2.4 GHz Wi-Fi with a local API; optional cloud dashboard
Voice assistants
None found
Matter
Not found
Open platforms
Home Assistant, Homey, ESPHome, openHAB and a local API
What can be connected
Indoor monitoring AirGradient ONE: CO2, PM, VOC, NOx, temperature and humidity with an LED bar and display
Outdoor monitoring AirGradient Open Air for particles, temperature and humidity outdoors
DIY Pre-soldered kits that owners assemble, with replaceable sensors and flashable firmware
A free app that shows a live air quality map (AQI and PM2.5) with alerts for saved places, plus Home and Lock Screen widgets. It draws on reference stations and AirGradient monitors worldwide and is not a controller for a monitor at home. Published by AirGradient. The Android package comes from a third-party index (Similarweb), and we could not load the Google Play page itself to confirm it. AirGradient also runs a web dashboard for monitor accounts, for which we found no separate app.
Official supported by the brandCommunity built by someone elseNot found searched, nothing foundUnconfirmed sources conflict or could not be opened
Platform
Status
What it means
Sources
Connection
Wi-Fi
Yes
The ONE uses an ESP32-C3 and 2.4 GHz Wi-Fi (802.11 b/g/n). First setup uses a temporary access point and a setup page at 192.168.4.1. One review lists no 5 GHz and no Ethernet.
Bluetooth LE is listed in the ONE's specifications by a review. The reviewer says BLE tracker code can be added to the ESPHome configuration, and another listing says its use is not described. AirGradient's own pages were not read for this.
Uploading to the AirGradient dashboard is optional and off by default, according to a review, and needs an account. It enables remote monitoring, analytics and email alerts. The local API documentation says a monitor can be set to local configuration control, and that a factory reset is needed if it was previously set to cloud.
A built-in AirGradient integration supports the ONE and Open Air over the local network, with auto-discovery and a one-minute poll (Local Polling). Devices on the legacy local API need firmware 3.1.1 or later. It exposes CO2, particles, VOC and NOx indices, temperature and humidity, and settings such as display, LED and CO2 calibration, and reports firmware updates without installing them. The listed maintainers include AirGradient. AirGradient joined the Works with Home Assistant program in August 2025, and Home Assistant says certified devices keep working locally.
AirGradient Co. Ltd. is listed as the developer of the Homey app, version 2.0.0. It has cloud and LAN drivers for indoor and outdoor monitors, and Homey Cloud users connect through an API token from the AirGradient dashboard. LED bar control is available only for locally connected indoor monitors. The listing shows Homey Cloud, Homey Pro, Homey Pro mini and Self-Hosted Server, but also says Homey Bridge is required, and we could not resolve which applies. It needs Homey 12.3.0 or later. Existing users must re-add devices to get the new drivers.
A review says the ONE can run custom firmware forked from an ESPHome project that AirGradient maintains in its own GitHub repository, and that AirGradient was working with ESPHome developers on an official branding programme. We did not open AirGradient's repository or ESPHome's device page to confirm.
An AirGradient API binding by an independent developer is tagged alpha in the openHAB community. It reads both the AirGradient cloud API and local device data, with mDNS discovery, and was tested on openHAB 4.1.1. Its latest listed release is from May 2024, and users reported a TVOC problem on firmware 3.4.1. We could not confirm whether it is in the official add-on list.
A GitHub project named Control4-AirGradientLocalAPI by an independent developer turned up in search. We did not open it, so scope and maintenance are unconfirmed.
No dedicated node, driver or plugin found in the searches run for this profile. The local API returns JSON over HTTP, so generic HTTP tools can read it, but we did not confirm a working setup.
Searched, no source
IFTTT
Not found
No IFTTT service found. A third-party comparison lists IFTTT as unsupported.
AirGradient's firmware repository documents a local server on ONE and Open Air monitors (firmware 3.0.10 and later). GET /measures/current returns readings as JSON, GET /config reads settings and PUT /config changes them, including CO2 calibration and LED tests. The monitor is reachable through mDNS, and the page describes no authentication step. The config also holds fields for an MQTT broker URL and an HTTP post domain. We read a mirror of the repository file rather than the original.
Checked 11 November 2026 against the brand's own pages, app store listings and each project's own page. “Not found” means we searched and found nothing, not that it is impossible. Compatibility changes often. Spot an error? Tell us and we will fix it.
Common questions about AirGradient
Does AirGradient support Matter?
Not that we could find. No Matter support found. A third-party comparison lists it as unsupported, and neither Home Assistant's nor Homey's pages mention it.
Does AirGradient work with Alexa?
Not that we could find. No integration found. Listed as unsupported by the same comparison, and searches for Alexa support returned nothing from AirGradient.
Does AirGradient work with Google Home?
Not that we could find. No integration found. A third-party comparison lists Google Home as unsupported, and AirGradient's Home Assistant and Homey pages do not mention it.
Does AirGradient work with Apple Home (HomeKit)?
Not that we could find. No HomeKit or Apple Home support found. Listed as unsupported by the comparison above.
Does AirGradient work with Home Assistant?
Yes. A built-in AirGradient integration supports the ONE and Open Air over the local network, with auto-discovery and a one-minute poll (Local Polling). Devices on the legacy local API need firmware 3.1.1 or later. It exposes CO2, particles, VOC and NOx indices, temperature and humidity, and settings such as display, LED and CO2 calibration, and reports firmware updates without installing them. The listed maintainers include AirGradient. AirGradient joined the Works with Home Assistant program in August 2025, and Home Assistant says certified devices keep working locally.
Does AirGradient work with SmartThings?
Not that we could find. No integration found. Listed as unsupported by the comparison above.
Does AirGradient work with Homey?
Yes, officially. AirGradient Co. Ltd. is listed as the developer of the Homey app, version 2.0.0. It has cloud and LAN drivers for indoor and outdoor monitors, and Homey Cloud users connect through an API token from the AirGradient dashboard. LED bar control is available only for locally connected indoor monitors. The listing shows Homey Cloud, Homey Pro, Homey Pro mini and Self-Hosted Server, but also says Homey Bridge is required, and we could not resolve which applies. It needs Homey 12.3.0 or later. Existing users must re-add devices to get the new drivers.
Answers come from the sourced table above. See how AirGradient compares with all brands on the smart home brand statistics page.