# Sudoku Extreme Hard Puzzles — Classic number airplane sodoku

> Classic Sudoku puzzles with customizable themes, difficulty levels, and progress tracking. (iPhone/iPad app by Pranoy Chowdhury.)

- Source: https://appshunter.io/ios/app/sudoku-extreme-hard-puzzles/id1451683705 (this page in markdown: same URL + `.md`)
- Developer: [Pranoy Chowdhury](https://appshunter.io/developer/952263202)
- Category: Games, Entertainment, Board, Puzzle
- Price: Free with in-app purchases
- Rating: 4.50/5 from 827 App Store ratings · 125 written reviews indexed
- Age rating: 4+
- Requires: iOS 15.0 · 29 MB
- Languages: American English
- Released: 2019-02-14
- Data updated: 2026-11-03
- Monetization: free with in-app purchases
- User reviews in markdown: https://appshunter.io/ios/app/sudoku-extreme-hard-puzzles/id1451683705/reviews.md

## What is Sudoku Extreme Hard Puzzles?

Sudoku Extreme is a beautiful way to experience classic Sudoku number puzzles for both beginners & advanced players! It includes over 100,000 puzzles from easy to hard levels. It works in airplane mode without wifi, no ads, and no subscriptions. It's a great way to keep your mind active while relaxing to pass time. Each puzzle has only one solution. The puzzle comes with a few cells pre-filled. Your job is to fill the remaining empty cells. Fill the empty cells with numbers 1-9 in a way that each row, column and block (3x3 cells) only contains a single instance of the number 1-9.

- Over 100,000 puzzles in 6 difficulty levels: beginner, easy, medium, hard, unfair and extreme.
- Highly customizable with many beautiful themes as well as settings to customize the app exactly the way you like it. App comes with both light and dark amoled themes to be comfortable on your eyes!
- The simple to use notes and hint features help you if you get stuck but I encourage spending time trying to figure out the puzzles without using hints. Cells filled with use of hints don't get any points.
- Haptic feature gives a positive vibration when correct and negative vibration when wrong answer is filled in the sodoku puzzle. This can be disabled in settings.
- If you make a mistake you can use the undo, delete and redo buttons. Note that each mistake deducts points from your overall score.
- Long press the undo button to restart the game
- After a game is finished, you get your overall stats like total time spent, best time, average time, overall score, hints used, mistakes made etc. Sudoku Extreme also comes with a graph of how your scores progress over time. As you play more difficult levels, you get more score. Each higher level gives twice the number of points as the previous level.
- Game can be paused and you can resume the previous game when you come back.
- Sudoku Extreme can automatically pre-fill the notes and auto-remove them when they are used in a row, column or block. Though I encourage disabling this setting and filling it manually as it makes your brain more active! Manually filling notes also gets you extra points! Long pressing the notes button lets you fill remaining notes automatically at any point in the game. Swiping up and down on the notes button still lets you toggle their display hidden/unhidden.
- The quick fill feature lets you tap-and-hold a number and then simply tap cells and it will fill it with that number.
- Long press a cell with only 1 candidate note to quick fill it.
- Numbers show how many instances of that number are left to be filled in the puzzle. When a number has been used 9 times correctly, it hides itself. You can disable this setting if you like.
- You can swipe up/down to enter notes numbers quickly without having to enter edit/note mode (setting needs to be switched on)
- There is a setting to allow up to 3 mistakes without being penalized in your score.
- "Export Scores" from the app. This can be used in Excel.
- No intrusive ads, trackers, subscriptions, or other nonsense.
- As a solo indie developer, there are ongoing costs of developing and maintaining the game. You can try out all difficulty levels and customizations during free trial. A one-time-only purchase unlocks over 100,000 puzzles and all difficulty levels for lifetime. It also helps me keep the game ad-free. No subscription. It's a small and fair amount which helps cover development costs of future updates.

You can also leave me a positive rating on the app store as that helps get the word out to others!

Thank you for supporting me. Hope you enjoy the puzzles :)

Send me feedback at:
pran@pranapps.com

## Key features

- Multiple difficulty levels
- Customizable themes and settings
- Notes and hint features
- Haptic feedback
- Undo, delete, and redo functions
- Detailed game statistics and progress graphs
- Quick fill and auto-fill options

## Pricing and in-app purchases

Base price: Free.

**One-time purchases**

| Purchase | Price | Type |
| --- | --- | --- |
| Sudoku Extreme Premium | $9.99 | one-time |


## What do users think of Sudoku Extreme Hard Puzzles?

Reviews of Sudoku Extreme Hard Puzzles are mostly positive: the game is rated 4.5/5 from 827 App Store ratings. What users like most: smooth gameplay, customizable themes. Top complaints: difficulty levels not properly calibrated, accidental number input issues. Summarized from real user reviews.

**Pros**

- 🚀 Smooth gameplay
- 👍 Customizable themes
- 🔒 No data tracking
- 💡 Detailed statistics and graphs
- 👍 Intuitive user interface
- 🚀 Responsive and fast
- 👍 Comprehensive features

**Cons**

- 🐛 Difficulty levels not properly calibrated
- 🐛 Accidental number input issues
- 💰 Paywall for basic settings
- 🐛 Inconsistent difficulty across puzzles

**Commonly reported bugs**

- Scoring system inconsistencies at higher levels
- Animation issues causing delays in rapid input

**Most requested features**

- Option to disable auto-fill notes
- Ability to resume unfinished games
- Coloring and advanced note-taking tools
- Sync progress across devices
- Difficulty level selector before starting a game

## Is Sudoku Extreme Hard Puzzles safe?

Sudoku Extreme Hard Puzzles appears safe based on user ratings. The AppsHunter Safety Score for Sudoku Extreme Hard Puzzles is 90 out of 100. This assessment is based on 827 user ratings, with an App Store average of 4.5 out of 5. Of 827 App Store ratings, 88.8% point to a safe experience, 3.7% suggest some concerns, and 7.5% point to a risky experience.

## Is Sudoku Extreme Hard Puzzles legit?

Sudoku Extreme Hard Puzzles appears to be a legitimate app. The AppsHunter Legitimacy Score for Sudoku Extreme Hard Puzzles is 95 out of 100 points across 7 verification signals from App Store and developer data.

## Recent user reviews (10 of 125)

All indexed reviews: https://appshunter.io/ios/app/sudoku-extreme-hard-puzzles/id1451683705/reviews.md

### 3/5 — Some good accessibility features, room for improvement

*2026-09-30*

No white flashes on startup and has dark mode and light mode themes. Lots of customizable settings that are immediately available with no searching but the wall of text might be best organized with headers. But there is one big issue. 
There is a bug where puzzles get wiped when you leave them and you don't get the opportunity to resume them. And it has nothing to do with changing difficulties. Sent a screen recording when dev asked. Developer did not fully watch it or they would have not responded to me saying it was because I switched difficulties (and even it was, that means the game punishes players who get better or want to take it easier; that is still a bug).
Also intelligent hints would be good down the line.

**Developer response:** Thanks for reaching out.
When you switch difficulty level, it clears out the previous game because otherwise, it'd be confusing seeing for example a previous Easy game when you have switched to a Medium difficulty. It also clears out the previous game if you change a setting which may impact the puzzle (for same reason of preventing confusion). However, I will add a setting to prevent this behavior.

I opted for all settings available in the settings screen at once so as to prevent having to click through multiple pages to find a setting. But I do plan on adding headers and a search feature to easily find the setting in there and better organization.

Detailed hints are also on my todo list. I will be adding it in an update.

### 3/5 — Unnötige Vorgabe + unrealistische Auswertung

*2026-08-06*

Es sollten beim Spielen nicht alle Möglichkeiten der Feldzahlen angegeben werden.

Außerdem scheint die Auswertungsstatistik unrealistische Ergebnisse zu beinhalten: Wer schafft es, ein (mittelschweres) Sudoku in 00:01 zu lösen? Das geht schon allein wegen der Schnelligkeit der manuellen Eingabe nicht!

**Developer response:** Hello, I apologize for having a hard time understanding the issue as I don't understand German. However, based upon Google Translate, if I am understanding correctly, you have 2 issues which I address below:

1. Your first issue is "Not all possible cell values ​​should be specified during gameplay"

Is this referring to the notes? If so, you can easily disable auto-filling of notes in settings.

2. Your second issue is "Furthermore, the evaluation statistics seem to include unrealistic results: Who can solve a (medium-difficulty) Sudoku in 00:01?"

The score is simply telling you how fast the quickest cell was solved (not the whole puzzle). Cells which only have 1 possible result (when all other numbers have been used in the row, column and block) can in fact be filled in 1 second by long pressing the cell. Long pressing a cell auto fills that cell when only 1 possible number is remaining.

I hope this answers your question and you update your review. If you still have questions or if I didn't understand your issue correctly, please email me at:

pran@pranapps.com

### 5/5 — Best sudoku app

*2026-07-29*

I’ve tried so many and this is by far my favorite sudoku app. I do wish there was a level between easy and medium. The easy ones are very simple and with the mediums I find myself sometimes stuck and can’t solve the puzzle so have to guess. I have looked up advanced strategies and have used many and gotten better, but still there are times when I see no way to move forward. Don’t know if that would be added on at some point, not just a hint at telling you a number but actually a strategy you can use to solve it at that point. This would take some doing I’m sure. Regardless I will still be playing my mediums and occasionally a hard puzzle. Great app!

**Developer response:** Thank you! The latest update now lets you try all Levels and change settings and themes for Free. However, I do hope some users try out the app and purchase the one-time-only purchase to support me.

I am a small indie developer. I do not use any ads whatsoever because I value user privacy. The only way for me to support ongoing development, maintenance of the app and developer fees is by having a single in app purchase. The in app purchase is also a small single one time only purchase and there are no subscriptions as I understand users dislike those. I think this model is quite fair as one gets to try the app and if they enjoy, they can buy the small 1 time only in app purchase to support development. I hope this explains my situation.

If you have questions, please email me at pran@pranapps.com

### 5/5 — Great App Hoping for More Future Updates & Features

*2026-07-24*

EDIT** Developer is continuing to update and has listened and added our requests :) Best sudoku app on the market. Well worth the premium purchase

Latest update was 3 years ago, and I purchased the premium version to support the developer. I really hope this app continues to receive updates, as it has a lot of potential. I do have a few suggestions:

* Add an option where using the “X” also removes notes from cells
* Include a toggle that allows up to 3 mistakes (can be edited) per game
* Expand customization options. More colors or even a color wheel would be great

Overall, I’d love to see this app continue to grow with more features and improvements.

**Developer response:** Hello, the latest update now includes a setting to allow up to 3 mistakes.

Would you mind emailing me what you mean by "using the “X” also removes notes from cells"? Do you want it to remove all notes from that cell?

pran@pranapps.com

### 5/5 — Super Sudoku App

*2026-07-19*

Die App ist super. Sie sieht gut aus und man kann viele Dinge anpassen und ändern. Ich nutze sie mittlerweile seit Jahren und kann sie jedem der Sudoku mag empfehlen. 

Der Entwickler ist sehr nett und reagiert super schnell auf Nachrichten.

**Developer response:** Thank you!

### 5/5 — Addictive

*2026-07-09*

One of the better ones available. No troublesome Ads and engaging difficulty levels. Can be better by including a restart option for any puzzle midway.

**Developer response:** Thank you for the kind words. You can restart any puzzle midway by long pressing the undo button and it will ask you if you want to restart. - Pran (developer)

### 1/5 — Kind of disappointing

*2026-06-04, version 7.0*

I had hoped that this app would teach sudoku concepts, rather than just give a hint by telling you a number. 
I had a great sudoku app that is no longer made, and it let me scan games in as well as taught different techniques. So when you asked for a hint, it would say something like “look for a naked pair” rather than saying “do you accept defeat?“ I think that’s just insulting and stupid because it doesn’t teach anything. It just fills in the number for you.

### 5/5 — Great App Hoping for More Future Updates & Features

*2026-04-29, version 7.0*

Latest update was 3 years ago, and I purchased the premium version to support the developer. I really hope this app continues to receive updates, as it has a lot of potential. I do have a few suggestions:

* Add an option where using the “X” also removes notes from cells
* Include a toggle that allows up to 3 mistakes (can be edited) per game
* Expand customization options. More colors or even a color wheel would be great

Overall, I’d love to see this app continue to grow with more features and improvements.

### 5/5 — One of the better sudoku apps

*2025-12-14, version 7.0*

Nice themes, good gameplay. I’d really like to see GameCenter syncing of my scores between devices.

### 4/5 — GREAT App

*2025-11-10*

Points for stating how you score the puzzle, with a simple strategy to maximize points. BIG niggle: I would like to reset the statistics preferably each difficulty separately. I like to play 25 games at a go. Currently the only way I see is to delete and DL. Small niggle: currently if you abandon a game (can’t solve) the game isn’t noted in the games played statistic. There doesn’t have to be a penalty but a simple counter would be nice.
Finally, the game before paying the app came off sort of clunky to me, if you find this, ignore it and unlock the full game. Worth every penny

**Developer response:** Hello

The latest update now includes a feature where you can just swipe left on a level to reset its scores. So now, you don't need to delete and redownload the app. Hope you update your review after trying :)

Pran

## Frequently asked questions about Sudoku Extreme Hard Puzzles

### What is Sudoku Extreme: Classic Number?

Sudoku Extreme is a mobile application that offers classic Sudoku puzzles for players of all levels. It provides a relaxing way to keep your mind active, featuring a single solution for each puzzle. The app allows you to fill in missing numbers based on Sudoku rules.

### What are the key features of Sudoku Extreme?

Key features include six difficulty levels from beginner to extreme, customizable themes with light and dark modes, and helpful tools like notes and hints. It also offers haptic feedback, undo/redo options, detailed game statistics, and progress tracking.

### How much does Sudoku Extreme cost?

The app is free to download and play, with no ads or subscriptions. Advanced levels, themes, and settings customization are available through a small, one-time in-app purchase to support development.

### What devices is Sudoku Extreme compatible with?

While specific device compatibility is not detailed, the app is designed for mobile use. It offers both light and dark amoled themes for eye comfort, suggesting it is available on devices that support these display features.

### What are the common use cases for Sudoku Extreme?

This app is ideal for passing time, exercising your brain, and improving logical thinking skills. It's suitable for both beginners learning Sudoku and advanced players seeking a challenging experience, all within a customizable and ad-free environment.

## Version history (last 5 releases)

### 23 — 2026-10-30

- Updates for iOS 27 SDK.
- My game has over 100,000 puzzles in 6 difficulty levels. I don't use intrusive ads, trackers, subscriptions, or other nonsense. Only 0.2% of players in the last month chose to support this game via the one-time purchase. As a solo indie developer, it's unsustainable and that doesn't cover the ongoing costs of developing and maintaining the game. With this update, nothing changes for Pro users. Free users can try out all difficulty levels and customizations during the free trial. A one-time-only purchase unlocks over 100,000 puzzles and all difficulty levels for lifetime. It also helps me keep the game ad-free. No subscription. It's a small and fair amount which helps cover development costs of future updates.

Thank you for supporting me. Hope you are enjoying the puzzles :)

Send me feedback at:
pran@pranapps.com

### 22 — 2026-10-19

- Updated to iOS 27 SDK.
- My game has over 100,000 puzzles in 6 difficulty levels. I don't use intrusive ads, trackers, subscriptions, or other nonsense. Only 0.2% of players in the last month chose to support this game via the one-time purchase. As a solo indie developer, it's unsustainable and that doesn't cover the ongoing costs of developing and maintaining the game. With this update, nothing changes for Pro users. Free users can try out all difficulty levels and customizations during the free trial. A one-time-only purchase unlocks over 100,000 puzzles and all difficulty levels for lifetime. It also helps me keep the game ad-free. No subscription. It's a small and fair amount which helps cover development costs of future updates.

Thank you for supporting me. Hope you are enjoying the puzzles :)

Send me feedback at:
pran@pranapps.com

### 20 — 2026-10-17

- Updated to iOS 27 SDK.
- My game has over 100,000 puzzles in 6 difficulty levels. I don't use intrusive ads, trackers, subscriptions, or other nonsense. Only 0.2% of players in the last month chose to support this game via the one-time purchase. As a solo indie developer, it's unsustainable and that doesn't cover the ongoing costs of developing and maintaining the game. With this update, nothing changes for Pro users. Free users can try out all difficulty levels and customizations during the free trial. A one-time-only purchase unlocks over 100,000 puzzles and all difficulty levels for lifetime. It also helps me keep the game ad-free. No subscription. It's a small and fair amount which helps cover development costs of future updates.

Thank you for supporting me. Hope you are enjoying the puzzles :)

Send me feedback at:
pran@pranapps.com

### 19 — 2026-09-02

- Fixed a bug where long pressing notes button to auto fill notes wasn't displaying the notes automatically if they had been toggled hidden before.
- Fixed a bug where cell with a possible candidate was being highlighted even when notes were toggled off.
- Board now shows the level name at top.
- Long pressing the notes button now lets you fill remaining notes automatically. Swiping up and down on the notes button still lets you toggle their display hidden/unhidden.
- Fixed a bug where changing levels or some settings wasn't creating a new puzzle and offering to resume previous puzzle instead.
- As requested by a user, added two new settings which are OFF by default: "Different color for selected Row, Column, Block" and "Highlight entire cell of note containing selected number"
- Fixed the ordering of couple settings.
- Switched from brackets to triangles at corners of the selected cell.
As a solo indie developer, there are ongoing costs of developing and maintaining the game. I don't use intrusive ads, trackers, subscriptions, or other nonsense that get in the way of playing. I provide all levels and customizations for free, hoping that players who enjoy the game will consider supporting it. So I'm asking, humbly: if my game has brought you a moment of fun, please consider making a one-time purchase to help me keep it ad-free. No subscription. Just one small way to say thanks. It's a small and fair amount which helps cover development costs of future updates. You can also leave me a positive rating on the app store as that helps get the word out to others!

Thank you for supporting me. Hope you are enjoying the puzzles :)

Send me feedback at:
pran@pranapps.com

### 18 — 2026-08-28

- Fixed a bug where cell with a possible candidate was being highlighted even when notes were toggled off.
- Board now shows the level name at top.
- Long pressing the notes button now lets you fill remaining notes automatically. Swiping up and down on the notes button still lets you toggle their display hidden/unhidden.
- Fixed a bug where changing levels or some settings wasn't creating a new puzzle and offering to resume previous puzzle instead.
- As requested by a user, added two new settings which are OFF by default: "Different color for selected Row, Column, Block" and "Highlight entire cell of note containing selected number"
- Fixed the ordering of couple settings.
- Switched from brackets to triangles at corners of the selected cell.
As a solo indie developer, there are ongoing costs of developing and maintaining the game. I don't use intrusive ads, trackers, subscriptions, or other nonsense that get in the way of playing. I provide all levels and customizations for free, hoping that players who enjoy the game will consider supporting it. So I'm asking, humbly: if my game has brought you a moment of fun, please consider making a one-time purchase to help me keep it ad-free. No subscription. Just one small way to say thanks. It's a small and fair amount which helps cover development costs of future updates. You can also leave me a positive rating on the app store as that helps get the word out to others!

Thank you for supporting me. Hope you are enjoying the puzzles :)

Send me feedback at:
pran@pranapps.com

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## More apps by Pranoy Chowdhury

- [Fititude - Cardio, Workout, Exercise tracker and full log with music player for fitness and training](https://appshunter.io/ios/app/fititude-cardio-workout-exercise-tracker-and-full-log-with-music-player-for-fitness-and-training/id952263203)
- [Color Circle - Tap to Switch](https://appshunter.io/ios/app/color-circle-tap-to-switch/id1084246048)
- [Note Flash Music Sight Reading](https://appshunter.io/ios/app/note-flash-music-sight-reading/id1285315687)
- [OLEDify Pure Black Wallpapers](https://appshunter.io/ios/app/oledify-pure-black-wallpapers/id1416984528)
- [Keyboard Warrior Speed Typing](https://appshunter.io/ios/app/keyboard-warrior-speed-typing/id1435547020)
- [MoodWell: moody tracker diary](https://appshunter.io/ios/app/moodwell-moody-tracker-diary/id1443436795)

All apps by Pranoy Chowdhury: https://appshunter.io/developer/952263202

## Related topics

[extreme sudoku](https://appshunter.io/ios/topics/extreme-sudoku)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-11-03.*