AirGradient ONE vs Airthings View Plus

Choose the assembled AirGradient ONE for a fixed room monitor when local Home Assistant data is the priority: it combines NDIR CO2, particles and VOC/NOx indexes without requiring a cloud connection for that integration. Choose Airthings View Plus if you need radon, air pressure, battery placement or its larger e-ink display. Our default for a local monitoring setup is ONE; for a room where radon is part of the brief, it is View Plus.

This compares the fully assembled Wi-Fi ONE I-9PSL with one View Plus, model 2960. Specifications and support documents checked November 2, 2026; recommendations are based on documentation, with no physical test results.

Quick picks and sensor comparison

• Pick ONE for local data: native Home Assistant support and a local API; plan for USB power and a recorder.
• Pick View Plus for radon: radon alongside CO2 and PM2.5, with batteries or USB-C.

Compare specifications and all conditions

CO2

Assembled AirGradient ONE

Senseair S8 or S88, NDIR

Airthings View Plus

NDIR

PM2.5

Assembled AirGradient ONE

Plantower PMS5003, laser scattering

Airthings View Plus

Laser-based optical particle counter

Other particle sizes

Assembled AirGradient ONE

PM1 and PM10 also measured; maker says PM2.5 has highest accuracy

Airthings View Plus

PM2.5 is the specified output

VOC

Assembled AirGradient ONE

Sensirion SGP41 VOC index; relative changes

Airthings View Plus

Metal-oxide VOC sensor; reported in ppb

NOx

Assembled AirGradient ONE

NOx index

Airthings View Plus

Not listed

Radon

Assembled AirGradient ONE

Not listed

Airthings View Plus

Passive diffusion chamber, alpha spectrometry

Air pressure

Assembled AirGradient ONE

Not listed

Airthings View Plus

Included

Temperature / humidity

Assembled AirGradient ONE

Included

Airthings View Plus

Included

Screen

Assembled AirGradient ONE

1.3-inch OLED plus LED bar

Airthings View Plus

2.9-inch e-ink; up to four values

Power

Assembled AirGradient ONE

USB-C; wall adapter separate

Airthings View Plus

Six AA batteries or USB-C

Home Assistant route discussed here

Assembled AirGradient ONE

Local integration

Airthings View Plus

Cloud integration

Full comparison table ↔

Swipe to compare. Row labels stay visible.

Measurement or feature	Assembled AirGradient ONE	Airthings View Plus
CO2	Senseair S8 or S88, NDIR	NDIR
PM2.5	Plantower PMS5003, laser scattering	Laser-based optical particle counter
Other particle sizes	PM1 and PM10 also measured; maker says PM2.5 has highest accuracy	PM2.5 is the specified output
VOC	Sensirion SGP41 VOC index; relative changes	Metal-oxide VOC sensor; reported in ppb
NOx	NOx index	Not listed
Radon	Not listed	Passive diffusion chamber, alpha spectrometry
Air pressure	Not listed	Included
Temperature / humidity	Included	Included
Screen	1.3-inch OLED plus LED bar	2.9-inch e-ink; up to four values
Power	USB-C; wall adapter separate	Six AA batteries or USB-C
Home Assistant route discussed here	Local integration	Cloud integration

Measurement or feature	Assembled AirGradient ONE	Airthings View Plus
CO2	Senseair S8 or S88, NDIR	NDIR
PM2.5	Plantower PMS5003, laser scattering	Laser-based optical particle counter
Other particle sizes	PM1 and PM10 also measured; maker says PM2.5 has highest accuracy	PM2.5 is the specified output
VOC	Sensirion SGP41 VOC index; relative changes	Metal-oxide VOC sensor; reported in ppb
NOx	NOx index	Not listed
Radon	Not listed	Passive diffusion chamber, alpha spectrometry
Air pressure	Not listed	Included
Temperature / humidity	Included	Included
Screen	1.3-inch OLED plus LED bar	2.9-inch e-ink; up to four values
Power	USB-C; wall adapter separate	Six AA batteries or USB-C
Home Assistant route discussed here	Local integration	Cloud integration

Table sources: AirGradient product specifications, ONE specification sheet, View Plus product sheet and Home Assistant's Airthings documentation.

Sensor counts hide the buying decision. ONE's NOx index does not substitute for View Plus's radon measurement. Nor should you compare ONE's relative VOC index directly with Airthings' ppb value as if they shared a scale. AirGradient explicitly describes its index as changes rather than absolute concentrations.

• Yes: Need local Home Assistant collection: choose ONE
• Yes: Need radon alongside CO2 and particles: choose View Plus
• Partly: Need comparable VOC numbers across brands: the published outputs use different scales

For alternatives to this pair, use our CO2 monitor shortlist. This page concentrates on the kit and data workflow.

Best for local data: AirGradient ONE

ONE is our pick when you want to collect readings on your own network. AirGradient documents a native Home Assistant integration that works locally; keep the stock firmware current for that route. Its local API instructions also describe direct JSON readings from the monitor on the same Wi-Fi network without a dashboard API token.

Buy assembled deliberately. The assembled version comes with a test report and a twelve-month warranty. The DIY kit shares the hardware but needs assembly and lacks the assembled version's warranty, certifications and test report. Published PM2.5 accuracy also differs: ±4 μg/m³ for assembled versus ±10 μg/m³ for the kit over 0–100 μg/m³. Those are maker specifications, not comparative results from us.

For a bedroom, the LED bar can be switched off. The display controls provide separate day/night screen and LED brightness settings; check the required firmware. The main compromise is power and recording: ONE needs its USB supply, and it has no internal history buffer.

See the assembled ONE at AirGradient

Best for radon and battery placement: Airthings View Plus

View Plus is our pick if radon belongs in the same room dashboard as CO2 and particles. Its e-ink display shows up to four selected values, configured in the app; a wave activates the colored status indicator. The published package includes six AA batteries and a USB cable. If you intend to use USB power, check the wall-adapter provision rather than assuming a cable means a complete mains kit.

The View Plus page rates battery life at up to two years, depending on router and reporting interval. USB-C enables its hub function for compatible Airthings Wave devices. That hub feature connects other monitors; Home Assistant's documented View Plus route still uses the cloud.

The free iOS/Android app handles setup and trends and requires an account. Its product sheet identifies Bluetooth as the onboarding connection, with Wi-Fi carrying the internet connection.

Check price on Amazon

Local access, cloud history and outages

Local collection: AirGradient's Home Assistant instructions say to tick the setup box disabling data transmission to AirGradient for cloudless use. Choosing a local integration alone is not the same as disabling cloud sending. Keep your own recorder running if you want history.

Cloud collection: ONE's hosted dashboard requires Wi-Fi and registration. Airthings likewise sends readings to its cloud for the app/dashboard. Home Assistant's Airthings integration uses dashboard credentials and API client credentials and is classified Cloud Polling. View Plus can therefore fit Home Assistant, but the documented route differs from ONE's direct local connection.

History and export: both makers document CSV export. Their limits mean different things:

These are AirGradient's export/retention rules and Airthings' export instructions. A one-year export window is not a statement that older data is deleted. For ONE, distinguish raw un-bucketed readings from averaged exports that include raw and corrected data.

Outages: AirGradient says ONE cannot save readings during Wi-Fi loss for later upload. Its offline mode still displays readings. Airthings documents approximately two hours of buffering, depending on interval. Neither is our choice for a planned long network outage; ONE's local collection is useful when the internet fails but the local network and recorder remain available.

Power, Wi-Fi and room setup

Both use 2.4 GHz Wi-Fi. ONE's setup guide uses its temporary hotspot and a browser; View Plus uses the phone app. Both makers exclude captive-portal networks from their documented setup, so check an office or guest network before ordering.

Complete the ONE power kit. Its two-meter USB-A-to-USB-C cable is included, but the adapter is not. The power guide specifies 5 V, 2 A and advises against computer USB ports or underpowered hubs. The sales table instead says greater than 2 A; confirm compatibility if reusing an exactly 2 A supply. The unboxing list includes two stands, while the sales page calls stands optional: check the shipped kit.

View Plus power changes particle sampling. Its starter guide specifies PM sampling every 2.5 minutes on USB, every 10 minutes by default on batteries, or every 60 minutes in the battery-saving setting. CO2 samples every five minutes. Hourly cloud updates can therefore make the app look older than the display; a fresh screen reading does not guarantee a fresh upload.

Choose a representative indoor position near breathing height, keep airflow openings clear, and avoid direct sunlight and ventilation outlets, following the ONE setup guidance and View Plus guidance. Airthings advises keeping the monitor stationary during its radon measurement period. For interpreting moisture readings, see indoor humidity and hygrometers.

1. 1

   Choose the position

   Follow the maker's placement guidance and keep airflow openings unobstructed.

2. 2

   Choose power and connection

   Complete the power kit and verify the room's Wi-Fi before fixing the monitor in place.

3. 3

   Choose where history lives

   Set up the cloud account or local recorder, then check that readings actually arrive.

Calibration and specification conflicts

Allow seven days for View Plus's initial CO2 and VOC calibration, according to its calibration guide. For radon, that guide recommends at least 30 days, ideally two months, of continuous measurement. An overnight comparison cannot establish its long-term radon performance.

For CO2, Airthings uses the lowest weekly reading as its fresh-air baseline. AirGradient's sales page/spec sheet say its automatic baseline cycle is seven days, adjustable or disableable; its calibration support guide instead describes an eight-day default. Check the actual firmware setting. AirGradient explains that a persistently occupied, unventilated room can make that baseline assumption understate readings; ask about the calibration configuration for such a room.

Do not select View Plus by its most favorable CO2 accuracy claim. Its own documents differ:

The particle documents disagree too: the product page/PDF give a PM2.5 range of 0–1000 μg/m³, while the help specifications give 0–200 μg/m³ and different error figures. Ask Airthings which document applies to the supplied unit. ONE lists S8 or S88 CO2 modules with different specified accuracy ranges; identify the supplied module before making a numerical comparison. We would choose by sensors and data access, not declare an accuracy winner from these documents.

Buying checklist: assembled unit, single monitor or bundle?

• ONE: order the assembled Wi-Fi version if you want the warranty and test report discussed here. The DIY kit and separate I-9PSL-CE cellular model are different purchase decisions.
• View Plus: check model 2960 and quantity. View Plus Duo means two View Plus monitors; View Plus + Wave Enhance and View Plus + View Radon add different monitors. Do not assume every room in a mixed bundle gets the View Plus sensor set.
• Before a holiday purchase: verify the recipient's network, app/account preference, power adapter and stand provision. Save the exact package description and ask the maker about unresolved cloud or specification terms before paying.

How we choose

We compared manufacturer product pages, specification sheets and support instructions, plus Home Assistant's official integration documentation. Picks prioritize the required measurements, local versus cloud access, useful history and a complete room setup. Published accuracy and battery life are manufacturer claims; this is a documentation comparison. We identify disagreements instead of treating unlike conditions as a ranking. Our editorial method is on How we choose.

Verdict

Buy assembled AirGradient ONE for a fixed, locally recorded setup. Buy View Plus for radon, e-ink and battery placement. Before ordering either, settle where history will live and match the exact kit to your power, network and calibration requirements.