# TOPIX vs J1939FaultCode

The clearest difference is in-app purchases: TOPIX at none against J1939FaultCode's 1. TOPIX also leads on ads (none vs shown) and device support (3 vs 1). J1939FaultCode's advantage is update cadence (fortnightly vs every 2 months). On price there is nothing between them.

Both are free to download. J1939FaultCode sells 1 one-off in-app purchase. TOPIX asks for nothing beyond the download.

TOPIX ships an update every 2 months, J1939FaultCode fortnightly. The most recent releases landed on November 8, 2026 and November 5, 2026 respectively.

## The numbers

| Metric | TOPIX | J1939FaultCode |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 2 months | **Fortnightly** |
| Size | 46 MB | 14 MB |
| Requires iOS | **12.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [TOPIX Business Software AG](https://appshunter.io/developer/406479000) | [洋 刘](https://appshunter.io/developer/6775317751) |

## What reviewers say

### TOPIX

[App page](https://appshunter.io/ios/app/topix/id6474665830)

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

**In-app purchases:** none


### J1939FaultCode

[App page](https://appshunter.io/ios/app/j1939faultcode/id6778431735)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| J1939 Pro | $2.99 | one-time |


## Frequently asked questions

### Is TOPIX free?

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

### Is J1939FaultCode free?

J1939FaultCode is free to download, with in-app purchases available.

### Do TOPIX or J1939FaultCode have ads?

J1939FaultCode shows ads; TOPIX does not.

### Which is updated more often, TOPIX or J1939FaultCode?

TOPIX ships an update every 2 months, and J1939FaultCode fortnightly. Most recently, TOPIX was updated on November 8, 2026 and J1939FaultCode on November 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.*