# Common Error vs AI Grammar Check

The clearest difference is in-app purchases: Common Error at none against AI Grammar Check's 2. Common Error also leads on iOS requirement (7.0 vs 15.6). AI Grammar Check's advantage is update cadence (every 3 weeks vs every 35 months). On price, ads and device support there is nothing between them.

Both are free to download. AI Grammar Check sells 2 in-app purchases, starting at $6.99 per month. Common Error asks for nothing beyond the download.

Common Error ships an update every 35 months, AI Grammar Check every 3 weeks. The most recent releases landed on October 5, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Common Error | AI Grammar Check |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 35 months | **Every 3 weeks** |
| Size | 7 MB | 31 MB |
| Requires iOS | **7.0** | 15.6 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Le Thi Quynh Ny](https://appshunter.io/developer/1321764676) | [Amina Sehar](https://appshunter.io/developer/1823051162) |

## What reviewers say

### Common Error

[App page](https://appshunter.io/ios/app/common-error/id1224350614)

**Features:** macOS Compatibility

**In-app purchases:** none


### AI Grammar Check

[App page](https://appshunter.io/ios/app/ai-grammar-check-corrector/id6760130507)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $6.99 | per month |
| Yearly | $28.99 | per year |


## Frequently asked questions

### Is Common Error free?

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

### Is AI Grammar Check free?

AI Grammar Check is free to download, with in-app purchases available.

### Do Common Error or AI Grammar Check have ads?

Neither Common Error nor AI Grammar Check shows ads.

### Which is updated more often, Common Error or AI Grammar Check?

Common Error ships an update every 35 months, and AI Grammar Check every 3 weeks. Most recently, Common Error was updated on October 5, 2026 and AI Grammar Check on October 25, 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.*