# Noise Decibel Meter vs Ruler Studio

The clearest difference is update cadence: Ruler Studio at every 6 weeks against Noise Decibel Meter's every 8 months. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Noise Decibel Meter sells 1 in-app purchase, starting at $3.99 per month and Ruler Studio sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Noise Decibel Meter ships an update every 8 months, Ruler Studio every 6 weeks. The most recent releases landed on October 30, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | Noise Decibel Meter | Ruler Studio |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 8 months | **Every 6 weeks** |
| Size | 29 MB | 19 MB |
| Requires iOS | **12.0** | 13.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Packhorse Tech Co.,Ltd](https://appshunter.io/developer/1610710377) | [Spyridon Bousios](https://appshunter.io/developer/1168309944) |

## What reviewers say

### Noise Decibel Meter

[App page](https://appshunter.io/ios/app/noise-decibel-meter-db-meter/id6723885133)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 噪音分贝仪专业版 | $3.99 | per month |


### Ruler Studio

[App page](https://appshunter.io/ios/app/ruler-studio/id6777489772)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Ruler Pro Lifetime | $2.99 | one-time |


## Frequently asked questions

### Is Noise Decibel Meter free?

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

### Is Ruler Studio free?

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

### Do Noise Decibel Meter or Ruler Studio have ads?

Neither Noise Decibel Meter nor Ruler Studio shows ads.

### Which is updated more often, Noise Decibel Meter or Ruler Studio?

Noise Decibel Meter ships an update every 8 months, and Ruler Studio every 6 weeks. Most recently, Noise Decibel Meter was updated on October 30, 2026 and Ruler Studio on October 31, 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.*