# ROT13 Decoder vs Error Decoder AI

The clearest difference is in-app purchases: ROT13 Decoder at none against Error Decoder AI's 2. ROT13 Decoder also leads on iOS requirement (15.0 vs 17.6). Error Decoder AI's advantage is update cadence (fortnightly vs every 8 months). On price, ads and device support there is nothing between them.

Both are free to download. Error Decoder AI sells 2 in-app purchases, starting at $6.99 per 7 days. ROT13 Decoder asks for nothing beyond the download.

ROT13 Decoder ships an update every 8 months, Error Decoder AI fortnightly. The most recent releases landed on September 9, 2026 and September 16, 2026 respectively.

## The numbers

| Metric | ROT13 Decoder | Error Decoder AI |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 8 months | **Fortnightly** |
| Size | 16 MB | 55 MB |
| Requires iOS | **15.0** | 17.6 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [佳伟 蔡](https://appshunter.io/developer/1801859662) | [Thomas Enevoldsen](https://appshunter.io/developer/1840489157) |

## What reviewers say

### ROT13 Decoder

[App page](https://appshunter.io/ios/app/rot13-decoder/id6743629613)

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

**In-app purchases:** none


### Error Decoder AI

[App page](https://appshunter.io/ios/app/error-decoder-ai/id6754816374)

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlimited error code decodes. | $6.99 | per 7 days |
| Unlimited error code decodes | $24.99 | per month |


## Frequently asked questions

### Is ROT13 Decoder free?

ROT13 Decoder is free to download, with no in-app purchases.

### Is Error Decoder AI free?

Error Decoder AI is free to download, with in-app purchases available.

### Do ROT13 Decoder or Error Decoder AI have ads?

Neither ROT13 Decoder nor Error Decoder AI shows ads.

### Which is updated more often, ROT13 Decoder or Error Decoder AI?

ROT13 Decoder ships an update every 8 months, and Error Decoder AI fortnightly. Most recently, ROT13 Decoder was updated on September 9, 2026 and Error Decoder AI on September 16, 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.*