# JSON Master vs Robot Eyes

The clearest difference is in-app purchases: Robot Eyes at none against JSON Master's 1. JSON Master's advantage is device support (3 vs 1). On price, update cadence, ads and iOS requirement there is nothing between them.

Both are free to download. JSON Master sells 1 one-off in-app purchase. Robot Eyes asks for nothing beyond the download.

JSON Master ships an update every 8 days, Robot Eyes fortnightly. Both last shipped on November 10, 2026.

## The numbers

| Metric | JSON Master | Robot Eyes |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Every 8 days** | Fortnightly |
| Size | 5 MB | 51 MB |
| Requires iOS | **18.0** | 18.6 |
| Devices | **iPhone, iPad, Mac** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Volodymyr Sichka](https://appshunter.io/developer/1125187457) | [Colin Rooney](https://appshunter.io/developer/1838817479) |

## What reviewers say

### JSON Master

[App page](https://appshunter.io/ios/app/json-master/id6799075435)

**Features:** Vision Pro support, iPhone Duo support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| JSON Master Pro | $1.99 | one-time |


### Robot Eyes

[App page](https://appshunter.io/ios/app/robot-eyes-vision-and-pose/id6813734887)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is JSON Master free?

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

### Is Robot Eyes free?

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

### Do JSON Master or Robot Eyes have ads?

Neither JSON Master nor Robot Eyes shows ads.

### Which is updated more often, JSON Master or Robot Eyes?

JSON Master ships an update every 8 days, and Robot Eyes fortnightly. Most recently, JSON Master was updated on November 10, 2026 and Robot Eyes on November 10, 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.*