Best Portable CO2 Monitors

Portable CO2 monitors have become increasingly popular since the pandemic, as people want to assess ventilation quality in restaurants, gyms, hotels, and public transport before deciding whether to stay. A good portable monitor fits in your pocket or bag, runs on batteries for hours or days, and gives fast, accurate readings without needing WiFi or a power outlet. The Aranet4 pioneered this category, but several strong alternatives now exist at various price points. Whether you are a health-conscious traveler, a parent checking your child school air quality, or a professional doing site assessments, these are the best portable options available.

16 monitors rankedUpdated March 2026
1

Temtop LKC-1000S+

Price: $170
Accuracy: ±75 ppm
Sensor: NDIR
CO2PM2.5PM10TemperatureHumidity+1 more
2

Huma-i HI-150

Price: $130
Accuracy: ±75 ppm
Sensor: NDIR
CO2PM2.5VOCTemperatureHumidity
3

Temtop P600

Price: $200
Accuracy: ±50 ppm
Sensor: NDIR
CO2PM2.5PM10TemperatureHumidity
4

Aranet Aranet4 Home

Price: $200
Accuracy: ±50 ppm
Sensor: NDIR
CO2TemperatureHumidityAtmospheric Pressure
5

Kaiterra Laser Egg+ CO2

Price: $200
Accuracy: ±50 ppm
Sensor: NDIR
CO2PM2.5TemperatureHumidity
6

Aranet Aranet4 Pro

Price: $250
Accuracy: ±30 ppm
Sensor: NDIR
CO2TemperatureHumidityAtmospheric Pressure
7

PJRC CO2 Gadget DIY Kit

Price: $45
Accuracy: ±50 ppm
Sensor: NDIR
CO2TemperatureHumidity
8

Temtop M10

Price: $90
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
9

Gain Express CO2 Monitor 7752

Price: $140
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
10

Klein Tools ET110

Price: $140
Accuracy: ±75 ppm
Sensor: NDIR
CO2TemperatureHumidity
11

SAF Aranet4 Compatible Probe

Price: $180
Accuracy: ±50 ppm
Sensor: NDIR
CO2TemperatureHumidity
12

Amprobe CO2-200

Price: $320
Accuracy: ±50 ppm
Sensor: NDIR
CO2TemperatureHumidity
13

Extech CO250

Price: $350
Accuracy: ±50 ppm
Sensor: NDIR
CO2TemperatureHumidity
14

Testo 440 CO2 Kit

Price: $900
Accuracy: ±50 ppm
Sensor: NDIR
CO2TemperatureHumidity
15

CO2.Click CO2.Click

Price: $70
Accuracy: ±50 ppm
Sensor: NDIR
CO2
16

TFA Dostmann AirCO2ntrol Mini

Price: $75
Accuracy: ±75 ppm
Sensor: NDIR
CO2

Buying Tips: Best Portable CO2 Monitors

  • 1

    Battery life is the most critical factor for portable use. The Aranet4 leads with 2+ years on replaceable batteries, while rechargeable options typically last 6-12 hours per charge.

  • 2

    Compact size matters when you are carrying a monitor daily. Look for devices that weigh under 200 grams and fit comfortably in a jacket pocket.

  • 3

    Response time affects usability. Look for monitors that reach accurate readings within 2-3 minutes of entering a new environment rather than requiring a 10-minute warm-up.

  • 4

    Bluetooth connectivity lets you log data to your phone for later review, which is useful for building a picture of air quality in places you visit regularly.

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