# Aura CO2 vs Clairsense

The clearest difference is in-app purchases: Aura CO2 at none against Clairsense's 1. Clairsense's advantage is update cadence (every 3 weeks vs every 3 months). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Clairsense sells 1 in-app purchase, starting at $29.99 per year. Aura CO2 asks for nothing beyond the download.

Aura CO2 ships an update every 3 months, Clairsense every 3 weeks. The most recent releases landed on December 20, 2025 and September 16, 2026 respectively.

## The numbers

| Metric | Aura CO2 | Clairsense |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 3 weeks** |
| Size | 59 MB | 81 MB |
| Requires iOS | 14.0 | **13.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [ELICHENS](https://appshunter.io/developer/1538561088) | [ARTEQ ARGE VE MUHENDISLIK LIMITED SIRKETI](https://appshunter.io/developer/1662256239) |

## What reviewers say

### Aura CO2

[App page](https://appshunter.io/ios/app/aura-co2/id1565190899)

**Features:** macOS Compatibility

**In-app purchases:** none


### Clairsense

[App page](https://appshunter.io/ios/app/clairsense/id6470394555)

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Clairsense Pro | $29.99 | per year |


## Frequently asked questions

### Is Aura CO2 free?

Aura CO2 is free to download, with no in-app purchases.

### Is Clairsense free?

Clairsense is free to download, with in-app purchases available.

### Do Aura CO2 or Clairsense have ads?

Neither Aura CO2 nor Clairsense shows ads.

### Which is updated more often, Aura CO2 or Clairsense?

Aura CO2 ships an update every 3 months, and Clairsense every 3 weeks. Most recently, Aura CO2 was updated on December 20, 2025 and Clairsense on September 16, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*