# Sound Meter vs Cairos IOT

The clearest difference is in-app purchases: Cairos IOT at none against Sound Meter's 1. On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Sound Meter sells 1 one-off in-app purchase. Cairos IOT asks for nothing beyond the download.

Sound Meter ships an update fortnightly, Cairos IOT every 3 weeks. Both last shipped on October 10, 2026.

## The numbers

| Metric | Sound Meter | Cairos IOT |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.4 (16 ratings)](https://appshunter.io/ios/app/sound-meter/id1560541986/reviews)** | — |
| Number of ratings | **16** | — |
| Positive reviews | 40.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Fortnightly** | Every 3 weeks |
| Monetization | Free with in-app purchases | — |
| Size | 57 MB | 34 MB |
| Requires iOS | 13.0 | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Hiep Pham](https://appshunter.io/developer/1040792388) | [JARS Services Private Limited](https://appshunter.io/developer/1157416886) |

## What reviewers say

### Sound Meter

[App page](https://appshunter.io/ios/app/sound-meter/id1560541986)

This utility app measures ambient noise levels in decibels. It provides a reference table to help users understand safe listening levels and protects their hearing. The app also stores historical measurements for later review.

**Highlights:** Measures sound level in decibels, Decibel level reference table, Hearing protection guidance, Stores measurement history, Easy to use interface

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove ADs | $4.99 | one-time |


### Cairos IOT

[App page](https://appshunter.io/ios/app/cairos-iot/id1663195314)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Sound Meter free?

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

### Is Cairos IOT free?

Cairos IOT is free to download, with no in-app purchases.

### Do Sound Meter or Cairos IOT have ads?

Neither Sound Meter nor Cairos IOT shows ads.

### Which is updated more often, Sound Meter or Cairos IOT?

Sound Meter ships an update fortnightly, and Cairos IOT every 3 weeks. Most recently, Sound Meter was updated on October 10, 2026 and Cairos IOT on October 10, 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.*