# Resistor color decoder vs Hardness Conversion Master

The clearest difference is in-app purchases: Resistor color decoder at none against Hardness Conversion Master's 1. Hardness Conversion Master's advantage is update cadence (every 3 days vs every 9 days). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Hardness Conversion Master sells 1 one-off in-app purchase. Resistor color decoder asks for nothing beyond the download.

Resistor color decoder ships an update every 9 days, Hardness Conversion Master every 3 days. The most recent releases landed on October 16, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | Resistor color decoder | Hardness Conversion Master |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | Yes | Yes |
| Update frequency | Every 9 days | **Every 3 days** |
| Size | 6 MB | 259 MB |
| Requires iOS | **17.0** | 17.6 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Michal Pajdak](https://appshunter.io/developer/1794089424) | [POYU WANG](https://appshunter.io/developer/1883764660) |

## What reviewers say

### Resistor color decoder

[App page](https://appshunter.io/ios/app/resistor-color-decoder/id6744559438)

**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 Resistor color decoder free?

Resistor color decoder is free to download, with no in-app purchases.

### Is Hardness Conversion Master free?

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

### Do Resistor color decoder or Hardness Conversion Master have ads?

Both Resistor color decoder and Hardness Conversion Master show ads.

### Which is updated more often, Resistor color decoder or Hardness Conversion Master?

Resistor color decoder ships an update every 9 days, and Hardness Conversion Master every 3 days. Most recently, Resistor color decoder was updated on October 16, 2026 and Hardness Conversion Master on October 5, 2026.

---

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