# Hardness Unit Converter vs Hardness Conversion Master

The clearest difference is price: Hardness Conversion Master at Free against Hardness Unit Converter's $1.99. Hardness Conversion Master also leads on update cadence (every 3 days vs every 5 months). Hardness Unit Converter's advantage is in-app purchases (none vs 1) and ads (none vs shown). On device support there is nothing between them.

Hardness Conversion Master is free to download; Hardness Unit Converter costs $1.99 up front. Hardness Conversion Master sells 1 one-off in-app purchase. Hardness Unit Converter asks for nothing beyond the download.

Hardness Unit Converter ships an update every 5 months, Hardness Conversion Master every 3 days. The most recent releases landed on September 29, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | Hardness Unit Converter | Hardness Conversion Master |
| --- | --- | --- |
| Price | $1.99 | **Free** |
| Rating | **[4.0 (7 ratings)](https://appshunter.io/ios/app/hardness-unit-converter/id1409248484/reviews)** | — |
| Number of ratings | **7** | — |
| Positive reviews | 0.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 5 months | **Every 3 days** |
| Monetization | Paid | — |
| Size | 1 MB | 259 MB |
| Requires iOS | **15.6** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Kei Suefuji](https://appshunter.io/developer/1388335881) | [POYU WANG](https://appshunter.io/developer/1883764660) |

## What reviewers say

### Hardness Unit Converter

[App page](https://appshunter.io/ios/app/hardness-unit-converter/id1409248484)

Easily convert hardness values between 12 different units, including Vickers, Brinell, Rockwell, and Shore. Input your value and select the desired unit for instant conversion, referencing ASTM E 140 standards and polynomial approximations for accuracy.

**Highlights:** Converts 12 hardness units, Vickers, Brinell, Rockwell, Shore support, Tensile strength conversion, ASTM E 140 reference, Polynomial approximation for data, Simple input and unit selection

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

**In-app purchases:** none


### Hardness Conversion Master

[App page](https://appshunter.io/ios/app/hardness-conversion-master/id6760411989)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Pro | $1.99 | one-time |


## Frequently asked questions

### Is Hardness Unit Converter free?

Hardness Unit Converter costs $1.99, with no in-app purchases.

### Is Hardness Conversion Master free?

Hardness Conversion Master is free to download, with in-app purchases available.

### Do Hardness Unit Converter or Hardness Conversion Master have ads?

Hardness Conversion Master shows ads; Hardness Unit Converter does not.

### Which is updated more often, Hardness Unit Converter or Hardness Conversion Master?

Hardness Unit Converter ships an update every 5 months, and Hardness Conversion Master every 3 days. Most recently, Hardness Unit Converter was updated on September 29, 2026 and Hardness Conversion Master on October 5, 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.*