# Unit Converter HD. vs ChangeUnits2

The clearest difference is price: Unit Converter HD. at Free against ChangeUnits2's $0.99. Unit Converter HD. also leads on ratings volume (644 vs 1) and iOS requirement (13.0 vs 15.6). ChangeUnits2's advantage is in-app purchases (none vs 1) and ads (none vs shown). On device support there is nothing between them.

Unit Converter HD. is free to download; ChangeUnits2 costs $0.99 up front. Unit Converter HD. sells 1 one-off in-app purchase. ChangeUnits2 asks for nothing beyond the download.

ChangeUnits2 holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Unit Converter HD. has 644 ratings behind it against 1, so its average is the more settled of the two.

Unit Converter HD. ships an update every 2 months, ChangeUnits2 every 4 weeks. The most recent releases landed on September 29, 2026 and June 1, 2026 respectively.

## The numbers

| Metric | Unit Converter HD. | ChangeUnits2 |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | [4.7 (644 ratings)](https://appshunter.io/ios/app/unit-converter-hd/id481973377/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/changeunits2/id1661260714/reviews)** |
| Number of ratings | **644** | 1 |
| Positive reviews | 93.8% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 2 months | **Every 4 weeks** |
| Monetization | **Free with in-app purchases** | Paid |
| Size | 86 MB | 17 MB |
| Requires iOS | **13.0** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [良峰 侯](https://appshunter.io/developer/654444245) | [Jack McCormack](https://appshunter.io/developer/1658121467) |

## What reviewers say

### Unit Converter HD.

[App page](https://appshunter.io/ios/app/unit-converter-hd/id481973377)

Easily convert over 700 units across 30 categories with this powerful tool. It offers a user-friendly interface, dark mode support, and a backspace key for quick corrections. Save time on all your measurement conversion needs.

**Highlights:** 700+ Units of Measure, 30 Conversion Categories, Easy-to-Use Interface, Dark Mode Support, Backspace Key

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Remove Ads Pack | $1.99 | one-time |

**What reviewers like**

- 👍 Easy to use
- 🚀 Handy and convenient
- 💡 Comprehensive set of conversions
- 🚀 Very useful app
- 👍 Intuitive design

**What reviewers complain about**

- 🐛 Occasional crashes or freezing issues
- 💡 Could be more intuitive for some users
- 🔒 Requires horizontal orientation

**Reported bugs**

- Freezing or crashing on some devices
- Display issues with certain units

**Requested features**

- Add support for US weights (tons, lbs., oz.)
- Implement portrait mode support
- Provide more customization options


### ChangeUnits2

[App page](https://appshunter.io/ios/app/changeunits2/id1661260714)

This powerful utility app offers lightning-fast and accurate unit conversions for a wide range of needs. It includes advanced math functions, currency exchange, time zone tracking, and even chemical equation balancing. Designed for professionals and everyday users alike, it works offline and remembers your last calculations.

**Highlights:** Extreme speed and accuracy, Offline functionality, Currency exchange converter, Global time zone tracking, Advanced math functions, Chemical equation balancing, Last 33 calculations remembered

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Unit Converter HD. free?

Unit Converter HD. is free to download, with in-app purchases available.

### Is ChangeUnits2 free?

ChangeUnits2 costs $0.99, with no in-app purchases.

### Which has better reviews, Unit Converter HD. or ChangeUnits2?

ChangeUnits2 is rated higher. Unit Converter HD. averages 4.7 out of 5 from 644 ratings, while ChangeUnits2 averages 5.0 from 1 ratings.

### Do Unit Converter HD. or ChangeUnits2 have ads?

Unit Converter HD. shows ads; ChangeUnits2 does not.

### Which is updated more often, Unit Converter HD. or ChangeUnits2?

Unit Converter HD. ships an update every 2 months, and ChangeUnits2 every 4 weeks. Most recently, Unit Converter HD. was updated on September 29, 2026 and ChangeUnits2 on June 1, 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.*