Aranet4 Home vs Airthings View Plus: Best CO2 Monitor Comparison

The Aranet4 Home and Airthings View Plus represent two fundamentally different philosophies in air quality monitoring. The Aranet4 is a specialist — a portable, battery-powered CO2 monitor built around the gold-standard NDIR sensor, designed to do one thing exceptionally well. The Airthings View Plus is a generalist — a comprehensive multi-sensor monitor that tracks seven air quality parameters including radon, PM2.5, CO2, VOCs, temperature, humidity, and barometric pressure.

Choosing between them depends on whether you need the best possible CO2 monitoring or the broadest possible air quality coverage. Based on our research into published specifications, customer reviews, and expert analysis, here is the definitive comparison.

Quick Decision Guide

Full Specs Comparison

CO2 Monitoring: The Core Comparison

Both monitors use NDIR (Non-Dispersive Infrared) sensors for CO2 measurement — the most accurate technology available in consumer devices. But the Aranet4's entire design is optimized around CO2 monitoring, while the Airthings treats CO2 as one parameter among seven.

Aranet4: The CO2 Specialist

The Aranet4 Home was designed from the ground up as a CO2 monitor. Its NDIR sensor covers a range of 0-9,999 ppm — nearly double the Airthings' 400-5,000 ppm range. While CO2 levels above 5,000 ppm are rare in most settings, the extended range matters for industrial environments, greenhouses, and worst-case scenarios in poorly ventilated spaces.

The Aranet4's e-ink display prominently shows the current CO2 reading in large, easy-to-read numbers with a traffic-light color indicator (green, yellow, red) that makes status immediately obvious from across a classroom or meeting room. The display also shows a trend arrow indicating whether CO2 levels are rising, falling, or stable — a feature teachers and office managers find invaluable for proactive ventilation decisions.

Customer reviews consistently praise the Aranet4's CO2 accuracy. Users who have compared it against reference-grade CO2 instruments report readings that track closely, and the device has become a favorite among indoor air quality professionals and researchers for its reliability.

The Aranet4 also includes an audible CO2 alarm that triggers when levels exceed a user-defined threshold — typically set at 1,000 or 1,400 ppm. This active alerting is valuable in classrooms and offices where someone may not be watching a display or checking an app.

Airthings View Plus: CO2 as Part of the Whole

The Airthings View Plus also uses an NDIR CO2 sensor, and customer feedback indicates it provides accurate and responsive readings. However, the Airthings measures CO2 within a narrower 400-5,000 ppm range. For typical home and office environments (where CO2 rarely exceeds 2,500 ppm), this range is perfectly adequate.

The Airthings e-ink display can be customized to show CO2, but it shares screen space with other parameters. The CO2 reading is not as prominently displayed as on the Aranet4, and there is no audible alarm — alerts come through the app as push notifications.

CO2 Accuracy Verdict

Both monitors deliver accurate CO2 readings for consumer-grade devices. The Aranet4 has a slight edge in sensor range, display prominence, and the audible alarm feature. For use cases where CO2 monitoring is the primary goal — classrooms, meeting rooms, ventilation verification — the Aranet4 is the more purpose-built tool.

Sensor Coverage: Airthings Has No Competition

This is where the comparison tilts dramatically in the Airthings View Plus's favor. Beyond CO2, temperature, humidity, and air pressure (which both monitor), the Airthings adds three critical sensors the Aranet4 lacks entirely:

Radon (Airthings Only)

Radon is a radioactive gas and the second leading cause of lung cancer. The Airthings View Plus provides continuous radon monitoring — the only consumer device in this price range to do so. If you live in a radon-prone area, this sensor alone can justify the $50 premium over the Aranet4.

PM2.5 (Airthings Only)

Fine particulate matter (PM2.5) from cooking, wildfires, traffic exhaust, and other sources is one of the most harmful indoor pollutants. The Airthings View Plus tracks PM2.5 levels in real time, alerting you when particle pollution rises. The Aranet4 has no particle sensor of any kind.

VOCs (Airthings Only)

Volatile Organic Compounds from cleaning products, paint, new furniture, and building materials affect indoor air quality. The Airthings View Plus includes a VOC sensor that flags elevated chemical levels. The Aranet4 does not measure VOCs.

The bottom line on sensor coverage: If you need comprehensive air quality monitoring, the Airthings View Plus is the only choice. If you specifically need CO2 monitoring and nothing else, the Aranet4 is more focused and more affordable.

Portability and Battery Life

Aranet4 wins decisively. The Aranet4 Home weighs just 4.4 ounces and fits in a pocket or bag. Its two AA batteries last up to 4 years — extraordinary longevity that means you can set it on a desk and forget about maintenance for years. This makes it ideal for:

• Classrooms: Teachers can move it between rooms or schools carry it in a bag
• Offices: Place it in any meeting room without worrying about power
• Travel: Monitor hotel rooms, airplane cabins, or conference venues
• Multi-room spot checks: Carry it from room to room to identify problem areas

The Airthings View Plus is also battery-powered (4x AA, lasting approximately 1 year) and cordless, which is a genuine advantage over plug-in monitors like the Awair Element. But at 8.8 ounces and a larger form factor, it is designed to sit in one location rather than travel with you. Its batteries need annual replacement versus the Aranet4's 4-year lifespan.

App and Connectivity

Aranet4 Home: Bluetooth-Only

The Aranet4 connects via Bluetooth only — no Wi-Fi. Data syncs to the Aranet Home app when your phone is in range, providing historical charts and trend analysis. This design choice prioritizes battery life (no Wi-Fi radio to drain power) and simplicity.

Limitations of Bluetooth-only:

• No remote monitoring — you must be near the device to sync data
• No smart home integration (no IFTTT, no Alexa, no Google Assistant)
• No cloud-based dashboard for viewing data from anywhere
• Data logging requires periodic phone proximity for sync

For classroom and office use where someone is always nearby, Bluetooth is adequate. For home monitoring where you want to check readings from another room or while away, the lack of Wi-Fi is a meaningful limitation.

Airthings View Plus: Full Connectivity

The Airthings View Plus connects via Wi-Fi, enabling:

• Remote monitoring from anywhere through the Airthings app or web dashboard
• Historical data stored in the cloud with daily, weekly, and monthly trends
• IFTTT integration for home automation (e.g., trigger a fan when CO2 exceeds 1,000 ppm)
• Alexa and Google Assistant voice queries
• Multi-device management for whole-home monitoring across several rooms

For home users who want continuous, always-connected monitoring, the Airthings ecosystem is significantly more capable.

Use Case Recommendations

Best for Schools and Classrooms: Aranet4 Home

The Aranet4 has become the de facto standard CO2 monitor in educational settings. Its large, clear CO2 display is readable from across a classroom. The audible alarm alerts teachers when ventilation is insufficient. The 4-year battery life means minimal maintenance. And the compact size makes it easy to share between classrooms or carry between buildings.

Schools and universities across Europe and North America adopted the Aranet4 during the COVID-19 pandemic for ventilation monitoring, and many continue using it. Customer reviews from educators consistently cite its simplicity and reliability as key advantages.

Best for Office Meeting Rooms: Aranet4 Home

Meeting rooms are notorious for CO2 buildup — six people in a small conference room can push CO2 above 1,500 ppm within 30 minutes. The Aranet4's prominent display and audible alarm make it a practical tool for prompting someone to open a window or turn on ventilation. No app needed — just glance at the display.

Best for Whole-Home Monitoring: Airthings View Plus

If you want to understand the air quality in your home comprehensively, the Airthings View Plus is the better investment. It monitors radon in your basement, PM2.5 during cooking or wildfire season, CO2 in your bedroom overnight, and VOCs when you clean or bring in new furniture. The Wi-Fi connectivity and cloud dashboard mean you can check readings from anywhere.

For multi-room monitoring, multiple Airthings devices feed into a single dashboard, giving you a whole-home view that the Aranet4's Bluetooth-only design cannot match.

Best for Travel: Aranet4 Home

At 4.4 ounces with a 4-year battery, the Aranet4 is the only practical travel CO2 monitor. Use it to check ventilation in hotel rooms, Airbnb rentals, airplane cabins, or conference venues. The Airthings is simply too large and feature-heavy for portable use.

Cost Comparison

The Aranet4 is $50 cheaper upfront and has negligible ongoing costs thanks to its extraordinary battery life. Over 5 years, the cost gap widens to approximately $72 in the Aranet4's favor.

However, the Airthings monitors five additional parameters (radon, PM2.5, VOCs, plus more capable connectivity). On a per-sensor basis, the Airthings is the better value — you are paying $50 more for significantly more functionality.

The Bottom Line

The Aranet4 Home is the best dedicated CO2 monitor you can buy. Its NDIR sensor, extended measurement range, prominent display, audible alarm, and extraordinary 4-year battery life make it the purpose-built tool for CO2 monitoring in classrooms, offices, and travel. If CO2 is your primary concern and you want a device that does one thing exceptionally well, the Aranet4 is the clear choice at $249.

The Airthings View Plus is the best comprehensive air quality monitor you can buy. It covers seven parameters including radon and PM2.5, connects via Wi-Fi for remote monitoring, and integrates with smart home platforms. If you want a single device that gives you a complete picture of your indoor air quality, the Airthings View Plus justifies its $299 price tag — especially if radon monitoring matters for your home.

Can you use both? Absolutely. Some air quality enthusiasts use an Aranet4 as a portable spot-checker and classroom/office tool while keeping an Airthings View Plus as the permanent home monitor. The two devices complement each other well, and at a combined $548, the pair covers every monitoring scenario.

Based on our research and customer feedback, both are excellent, reliable devices. The right choice depends entirely on whether you need a CO2 specialist or a comprehensive air quality generalist.