# UN Number vs ChesHaz

The clearest difference is review sentiment: ChesHaz at 100% against UN Number's 63%. ChesHaz also leads on in-app purchases (none vs 5) and rating (5.0 vs 4.7). UN Number's advantage is ratings volume (55 vs 4). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. UN Number sells 5 in-app purchases, starting at $1.99 per month. ChesHaz asks for nothing beyond the download.

ChesHaz holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: UN Number has 55 ratings behind it against 4, so its average is the more settled of the two. Written reviews point the same way: 63% of UN Number's written reviews are positive against 100% of ChesHaz's.

UN Number ships an update every 3 months, ChesHaz every 6 weeks. The most recent releases landed on November 6, 2026 and November 2, 2026 respectively.

## The numbers

| Metric | UN Number | ChesHaz |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.7 (55 ratings)](https://appshunter.io/ios/app/un-number/id307373793/reviews) | **[5.0 (4 ratings)](https://appshunter.io/ios/app/cheshaz/id1320963064/reviews)** |
| Number of ratings | **55** | 4 |
| Positive reviews | 63.0% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 6 weeks** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 44 MB | 3 MB |
| Requires iOS | 11.0 | **10.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [ZWEIDENKER Holding GmbH](https://appshunter.io/developer/307356444) | [WIlliam Cheswick](https://appshunter.io/developer/419708950) |

## What reviewers say

### UN Number

[App page](https://appshunter.io/ios/app/un-number/id307373793)

Quickly access essential information for hazardous materials emergencies. This reference guide provides detailed data based on established emergency response cards, usable even without an internet connection. It's designed for rapid retrieval of critical details in critical situations.

**Highlights:** Enter UN numbers via keypad, Quick information retrieval, Based on ERI-Cards, Offline functionality, Categorized data display, User-friendly interface

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

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| UN⁺ Monthly | $1.99 | per month |
| UN⁺ Yearly | $17.99 | per year |
| ADR Label | $0.99 | one-time |
| Hazard Diamond | $0.99 | one-time |
| Hommel | $2.99 | one-time |


### ChesHaz

[App page](https://appshunter.io/ios/app/cheshaz/id1320963064)

Quickly identify hazardous materials using four-digit UN/NA numbers found on placards. Access chemical names and additional information offline. Links to external resources provide further details.

**Highlights:** Offline UN/NA number lookup, Chemical name display, Links to Wikipedia, Links to NOAA information, Educational purposes

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is UN Number free?

UN Number is free to download, with in-app purchases available.

### Is ChesHaz free?

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

### Which has better reviews, UN Number or ChesHaz?

ChesHaz is rated higher. UN Number averages 4.7 out of 5 from 55 ratings, while ChesHaz averages 5.0 from 4 ratings.

### Do UN Number or ChesHaz have ads?

Neither UN Number nor ChesHaz shows ads.

### Which is updated more often, UN Number or ChesHaz?

UN Number ships an update every 3 months, and ChesHaz every 6 weeks. Most recently, UN Number was updated on November 6, 2026 and ChesHaz on November 2, 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.*