Best Co2 Check Apps

250+ iOS apps curated and reviewed

4.1 avg rating

20 free apps

Updated October 2026

From beginner-friendly picks to power-user tools, our co2 check list covers 250+ iPhone apps updated through October 2026. Compare ratings, prices, and screenshots in one place.

Compare top Co2 Check Apps (October 2026)

#	App	Price	Rating	Ads	In-App Purchases	Updated
1	C02 Monitor	Free	3.0★ (2)	No	No	May 2026
2	Altos: Air analyzer, CO2 Check	Free	—	No	No	May 2026
3	CO2 sensor	Free	3.4★ (7)	No	No	Oct 2026
4	CO2 Risk Calculator	Free	—	No	No	May 2026
5	CO2 Monitor 2	Free	—	No	No	May 2026
6	Gas Checker	Free	5.0★ (1)	No	No	Oct 2026
7	CO2 Filter Calc	Free	—	No	No	May 2026
8	Denbury CO2 Unit Converter	Free	—	No	No	Oct 2026

Top Picks for Co2 Check

#1

C02 Monitor by ReFleX Wireless Inc.

requires a wireless CO2 sensor

Editor's Choice

📊 Productivity

3.0(2 ratings)

Free

C02 Monitor screenshot 1

This application displays real-time CO2 levels from compatible wireless sensors. It provides a remote view of indoor air quality, helping users monitor their environment.

#2

Altos: Air analyzer, CO2 Check by Woodenshark LLC

Wellness and Productivity App

Strong Contender

📊 Productivity

0.0(0 ratings)

Free

Altos: Air analyzer, CO2 Check screenshot 1

Altos: Air analyzer, CO2 Check screenshot 2

Altos: Air analyzer, CO2 Check screenshot 3

Altos: Air analyzer, CO2 Check screenshot 4

Altos: Air analyzer, CO2 Check screenshot 5

#3

CO2 sensor by sighmon

Display SCD-41 CO2 readings.

Worth Considering

3.4(7 ratings)

Free

CO2 sensor screenshot 1

CO2 sensor screenshot 2

CO2 sensor screenshot 3

CO2 sensor screenshot 4

CO2 sensor screenshot 5

CO2 sensor screenshot 6

Monitor CO2, temperature, and humidity levels in real-time using a Bluetooth sensor. Save readings with location data and sync them across Apple devices via iCloud. View historical data on a map.

More Co2 Check apps to explore

CO2 Risk Calculator

CO2 Risk Calculator

CO2 Risk Calculator

by Logico2 International AB

Software for Gas Engineers

Streamline your gas and heating business with digital reporting and invoicing. Automate customer reminders, create PDF reports, and integrate with accounting software. Eliminate paper forms and manage all your job documentation efficiently.

Create PDF reports (certificates, invoices, quotes)Automated customer remindersDigital job sheets

CO2 Filter Calc

CO2 Filter Calc

CO2 Filter Calc

by TOMCO2 Systems Company

Denbury CO2 Unit Converter

Denbury CO2 Unit Converter

Denbury CO2 Unit Converter

by Exxon Mobil Corporation

Denver CO2 Risk Calculator

Denver CO2 Risk Calculator

Denver CO2 Risk Calculator

by Logico2 International AB

Visualise CO₂ Emissions in AR

by Logico2 International AB

Flight CO2 Calculator

Flight CO2 Calculator

Flight CO2 Calculator

Reduce your carbon footprint

Birdie - Fresh Air Company

Birdie - Fresh Air Company

Birdie - Fresh Air Company

Monitor indoor air quality, including CO2, temperature, humidity, mold risk, and local pollen. View historical data with graphs and access educational content about indoor climate. Connects via Bluetooth for a simple setup.

CO2, temperature, and humidity trackingMold risk and pollen level monitoringOutside air quality data

Flight CO2 Calculator - Protect the Climate

Flight CO2 Calculator - Protect the Climate

Flight CO2 Calculator - Protect the Climate

by Andrea Bizzotto

Calculate the CO2 emissions generated by your flights and offset them through donations to climate protection projects. This app helps you understand your travel's environmental impact and offers a way to mitigate it.

Calculate flight CO2 emissionsOffset emissions via donationsOffline flight calculator

Energy & CO2 calculator for iPhone

Energy & CO2 calculator for iPhone

Energy & CO2 calculator for iPhone

by iQ Media Ltd

IGC H₂-CO₂ Unit Conversion App

IGC H₂-CO₂ Unit Conversion App

IGC H₂-CO₂ Unit Conversion App

Industrial Gas Unit Conversion

Change climate on your phone

Bambu – Easy carbon credits

Bambu – Easy carbon credits

Bambu – Easy carbon credits

Carbon neutral lifestyle

Easily calculate and offset your carbon emissions to live a carbon-neutral lifestyle. Choose from a selection of certified nature projects to support positive environmental and social impacts.

Simple footprint calculationsAffordable carbon offsettingCarbon neutral lifestyle

carbon footprint calculator

FAQ about Co2 Check

What are the best co2 check apps for iPhone?

C02 Monitor tops our co2 check apps ranking as of October 2026, with a 3.0-star average from 2 App Store ratings, and it's free to download.

Are there free co2 check apps for iPhone?

Yes — 20 of the top co2 check apps we rank are free to download, including C02 Monitor and Altos: Air analyzer, CO2 Check.

Does C02 Monitor have ads or in-app purchases?

C02 Monitor has no ads and has no in-app purchases, according to its App Store listing as of October 2026.

How many co2 check apps are on the App Store?

We track 250+ co2 check apps on the iOS App Store as of October 2026, ranked by rating, recency, and analysis of real user reviews.

Related searches

altos: air analyzer, co2 check