# Sudoku 9 vs Challenge! Sudoku

The clearest difference is in-app purchases: Challenge! Sudoku at none against Sudoku 9's 2. Challenge! Sudoku also leads on ads (none vs shown) and update cadence (every 2 days vs every 4 weeks). Sudoku 9's advantage is ratings volume (21 vs 2). On price and device support there is nothing between them.

Both are free to download. Sudoku 9 sells 2 one-off in-app purchases. Challenge! Sudoku asks for nothing beyond the download.

Challenge! Sudoku holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Sudoku 9 has 21 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 90% of Sudoku 9's written reviews are positive against 100% of Challenge! Sudoku's.

Sudoku 9 ships an update every 4 weeks, Challenge! Sudoku every 2 days. The most recent releases landed on November 6, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Sudoku 9 | Challenge! Sudoku |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.8 (21 ratings)](https://appshunter.io/ios/app/sudoku-9/id403191170/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/challenge-sudoku-classic-game/id6468818921/reviews)** |
| Number of ratings | **21** | 2 |
| Positive reviews | 89.9% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 4 weeks | **Every 2 days** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 22 MB | 58 MB |
| Requires iOS | 15.0 | **12.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Gyuhyeon Jeon](https://appshunter.io/developer/353770805) | [kyulabs](https://appshunter.io/developer/1380867471) |

## What reviewers say

### Sudoku 9

[App page](https://appshunter.io/ios/app/sudoku-9/id403191170)

Engage in a variety of Sudoku puzzles with infinite levels and daily global competitions. Features include auto-saving, hints, memo functions, and social sharing options. Track your progress and compete on worldwide leaderboards.

**Highlights:** 5 types of Sudoku games, Daily worldwide Sudoku competition, Infinite puzzles at all levels, Auto-saving and unlimited undo/redo, Memo for candidate numbers, Hint function, Game Center integration for rankings

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Hint 50 | $0.99 | one-time |
| No Advertisement | $2.99 | one-time |


### Challenge! Sudoku

[App page](https://appshunter.io/ios/app/challenge-sudoku-classic-game/id6468818921)

Engage in classic Sudoku puzzles with a competitive edge. Challenge players globally and locally to achieve top rankings on leaderboards. Customize difficulty levels to suit your skill, from beginner to expert.

**Highlights:** Global ranking system, Compete with friends, Multiple difficulty levels, User-friendly interface, Record sharing

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

**In-app purchases:** none


## Frequently asked questions

### Is Sudoku 9 free?

Sudoku 9 is free to download, with in-app purchases available.

### Is Challenge! Sudoku free?

Challenge! Sudoku is free to download, with no in-app purchases.

### Which has better reviews, Sudoku 9 or Challenge! Sudoku?

Challenge! Sudoku is rated higher. Sudoku 9 averages 4.8 out of 5 from 21 ratings, while Challenge! Sudoku averages 5.0 from 2 ratings.

### Do Sudoku 9 or Challenge! Sudoku have ads?

Sudoku 9 shows ads; Challenge! Sudoku does not.

### Which is updated more often, Sudoku 9 or Challenge! Sudoku?

Sudoku 9 ships an update every 4 weeks, and Challenge! Sudoku every 2 days. Most recently, Sudoku 9 was updated on November 6, 2026 and Challenge! Sudoku on October 30, 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.*