# KDIAG vs CAR OBD

The clearest difference is rating: CAR OBD at 5.0 against KDIAG's 3.3. CAR OBD also leads on iOS requirement (13 vs 17.0). KDIAG's advantage is in-app purchases (none vs 5) and review sentiment (31% vs 0%). On price, ads and device support there is nothing between them.

Both are free to download. CAR OBD sells 5 one-off in-app purchases. KDIAG asks for nothing beyond the download.

CAR OBD holds the better App Store score, 5.0 against 3.3. That said, the two scores are not equally well evidenced: KDIAG has 20 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 31% of KDIAG's written reviews are positive against 0% of CAR OBD's, so the app with the better star average is not the one people write more warmly about.

KDIAG ships an update fortnightly, CAR OBD every 6 weeks. The most recent releases landed on October 24, 2026 and October 20, 2026 respectively.

## The numbers

| Metric | KDIAG | CAR OBD |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.3 (20 ratings)](https://appshunter.io/ios/app/kdiag/id6450169808/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/car-obd/id6470771313/reviews)** |
| Number of ratings | **20** | 1 |
| Positive reviews | **30.8% of reviews** | 0.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | **Fortnightly** | Every 6 weeks |
| Monetization | **Free** | Free with in-app purchases |
| Size | 74 MB | 15 MB |
| Requires iOS | 17.0 | **13** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [祖策 谢](https://appshunter.io/developer/983519195) | [Dongguan Shendu Research Intelligent Technology Co., Ltd.](https://appshunter.io/developer/1827187525) |

## What reviewers say

### KDIAG

[App page](https://appshunter.io/ios/app/kdiag/id6450169808)

This app offers comprehensive automotive fault detection and OBD functions for various car brands. It provides professional diagnostic services to quickly identify and resolve car issues, making driving safer and smoother for enthusiasts and professionals alike. The app supports 8 languages and is free to use.

**Highlights:** Comprehensive automotive fault detection, OBD functions, System fault diagnosis for mainstream brands, Free to use, Supports 8 languages, Professional diagnostic services

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

**In-app purchases:** none


### CAR OBD

[App page](https://appshunter.io/ios/app/car-obd/id6470771313)

This utility app helps users manage car keys by facilitating the matching of existing keys and the addition of new ones. It supports both single key additions and batch processing for multiple keys.

**Highlights:** Match car keys, Add single car key, Batch add multiple keys, Supports iPhone and iPad

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

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| OBD number recharge One | $3.00 | one-time |
| OBD number recharge Two | $6.00 | one-time |
| OBD number recharge three | $9.00 | one-time |
| OBD number recharge four | $12.00 | one-time |
| OBD number recharge five | $15.00 | one-time |


## Frequently asked questions

### Is KDIAG free?

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

### Is CAR OBD free?

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

### Which has better reviews, KDIAG or CAR OBD?

CAR OBD is rated higher. KDIAG averages 3.3 out of 5 from 20 ratings, while CAR OBD averages 5.0 from 1 ratings.

### Do KDIAG or CAR OBD have ads?

Neither KDIAG nor CAR OBD shows ads.

### Which is updated more often, KDIAG or CAR OBD?

KDIAG ships an update fortnightly, and CAR OBD every 6 weeks. Most recently, KDIAG was updated on October 24, 2026 and CAR OBD on October 20, 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.*