# Sudoku Checker — For your hand-made Sudoku > Sudoku puzzle solver and validator for hand-written grids. (iPhone/iPad app by Atsuo Kazama.) - Source: https://appshunter.io/ios/app/sudoku-checker/id1458321132 (this page in markdown: same URL + `.md`) - Developer: [Atsuo Kazama](https://appshunter.io/developer/1442822891) - Category: Utilities, Productivity - Price: Free - Rating: 4.00/5 from 3 App Store ratings · 7 written reviews indexed - Age rating: 4+ - Requires: iOS 9.0 · 23 MB - Languages: English, Japanese, Spanish - Released: 2019-05-02 - Data updated: 2026-08-11 - Monetization: free - User reviews in markdown: https://appshunter.io/ios/app/sudoku-checker/id1458321132/reviews.md ## What is Sudoku Checker? When launched, an empty number place table will appear. At first everything is "?". Enter the number of your own number place here. The entered numbers are displayed in black. If there are numbers that can be derived from the entered numbers, they will be displayed in gray. After completing the input, touch the [Verify] button to obtain the results. ・ When only one solution can be derived ・ When there are multiple solutions ・ When contradiction occurs The results are shown in the three dialogs of. At the moment, the ability to load your own number places with your camera and to capture from photos is not yet implemented. Display the ad at the bottom of the screen. ## Key features - Input hand-written Sudoku numbers - Displays derived numbers in gray - Verifies puzzle validity - Detects single/multiple solutions - Identifies contradictions ## Recent user reviews (7 of 7) All indexed reviews: https://appshunter.io/ios/app/sudoku-checker/id1458321132/reviews.md ### 5/5 — So helpful *2026-03-18, version 1.3.3* This has been great for helping me check puzzles and even make a few of my own. ### 3/5 — 矛盾 *2025-02-03, version 1.3.3* 「矛盾があります。確認してください」の表示はありがたいのだが、どこがどう矛盾しているかまで表示されるとより便利だと思う ### 5/5 — 世界一難しい数独TOP10も数秒で解けるスグレモノ *2021-07-13, version 1.2.3* いくつかの数独解答アプリを試した事があります。 Android Windows Mac iOS この中でもこのアプリは特に優れています。 タイトルにも書きましたが世界一難しい数独TOP10も数秒で解ける程の実力があります。 これは、AI数独解答アプリ等であれば、変な思考に陥ってしまい、アプリエラーが起こることもしばしばありましたが、このアプリだけはそんなことありません。 数独に没頭している方、答えが分からない際は是非おすすめしたいアプリです。 ### 4/5 — I’m confused *2021-06-09, version 1.2.2* What does there’s a contradiction mean ### 5/5 — 瞬間で解けちゃう *2021-02-11, version 1.2.1* すごい！ ### 4/5 — Nice! *2020-04-23* The only things it needs is image and photo recognition so that I don't have to type in all the individual numbers after I solve a sudoku puzzle on paper. ### 5/5 — すげえ！ *2020-01-26, version 1.2* いや、これ、めっちゃ凄いんだけどw ## Frequently asked questions about Sudoku Checker ### How does Sudoku Checker work? You manually enter the numbers from your hand-written Sudoku grid into the app. The app then analyzes your input to determine if it leads to a valid solution, multiple solutions, or a contradiction. ### What are the results shown by Sudoku Checker? After you input your numbers and touch the 'Verify' button, Sudoku Checker will display results in three dialogs: indicating if only one solution can be derived, if there are multiple solutions, or if a contradiction occurs. ### Can Sudoku Checker load puzzles from photos? Currently, Sudoku Checker does not have the ability to load your number places from a camera or capture them from photos. You need to manually input the numbers. ### What devices is Sudoku Checker compatible with? Sudoku Checker is available for iPhone, iPad, and iPod devices. ### What is the age rating for Sudoku Checker? Sudoku Checker has an age rating of 4+. ### How often is Sudoku Checker updated? The latest version, 1.3.3, was released on March 31, 2022. Updates are not frequent, with the last update being over a year ago. ### What is the user rating for Sudoku Checker? Sudoku Checker has a rating of 4.0 stars based on 3 ratings. ### Does Sudoku Checker have ads? Yes, Sudoku Checker displays an ad at the bottom of the screen. ## Version history (last 5 releases) ### 1.3.3 — 2022-03-31 Version 1.3.3 has the following modifications to 1.3.2. ・ The recognition sensitivity of the Sudoku technique called XY-Wing is increased. ・ The recognition sensitivity of the Sudoku technique called XYZ-Wing is increased. ・ We are increasing the recognition sensitivity of the Sudoku technique called the Hidden Triple. ・ We are increasing the recognition sensitivity of the Sudoku technique called skyscraper. ・ The recognition sensitivity of the Sudoku technique called swordfish is increased. Version 1.3.2 fixes the following bugs in 1.3.1. -Sometimes I couldn't recognize the Sudoku technique called X-Wing. -The X-Wing level and the Hidden Triples level are displayed in the difficulty nest display dialog. Version 1.3.1 fixes the following bugs in 1.3.0. -Sometimes it freezes while entering numerical values. Version 1.3.x has revised the calculation logic of the difficulty level. Previously (up to Version 1.2.x), the difficulty level was high when the number of hints was small, or the difficulty level was less than 300 even though advanced techniques were required. Therefore, the calculation logic is revised. The basic functions are the same as before. You can also call the calculation result of the past calculation logics. ### 1.3.2 — 2022-01-23 Version 1.3.2 fixes the following bugs in 1.3.1. -Sometimes I couldn't recognize the Sudoku technique called X-Wing. -The X-Wing level and the Hidden Triples level are displayed in the difficulty nest display dialog. Version 1.3.1 fixes the following bugs in 1.3.0. -Sometimes it freezes while entering numerical values. Version 1.3.x has revised the calculation logic of the difficulty level. Previously (up to Version 1.2.x), the difficulty level was high when the number of hints was small, or the difficulty level was less than 300 even though advanced techniques were required. Therefore, the calculation logic is revised. The basic functions are the same as before. You can also call the calculation result of the past calculation logics. ### 1.3.1 — 2021-12-30 Version 1.3.1 fixes the following bugs in 1.3.0. -Sometimes it hangs (freezes) while entering numerical values. In Version1.3, the calculation logic of the difficulty level has been revised. Previously (up to Version 1.2.x), the difficulty level was high when the number of hints was small, or the difficulty level was less than 300 even though advanced techniques were required. Therefore, the calculation logic is revised. The basic functions are the same as before. You can also call the calculation result of the past calculation logic. ### 1.3.0 — 2021-12-27 In Version1.3, the calculation logic of the difficulty level has been revised. Previously (up to Version 1.2.x), the difficulty level was high when the number of hints was small, or the difficulty level was less than 300 even though advanced techniques were required. Therefore, the calculation logic is revised. The basic functions are the same as before. You can also call the calculation result of the past calculation logic. ### 1.2.4 — 2021-10-07 Version 1.2.4 makes the following changes to Version 1.2.3. -Changed to display "advanced technique level" and "complexity index" in the difficulty level display dialog. -The "Clear" button in the dialog when a contradiction occurs has been eliminated. ## Apps similar to Sudoku Checker | App | Rating | Price | Category | | --- | --- | --- | --- | | [Counter +](https://appshunter.io/ios/app/counter-plus/id478557426) | 4.2 (384) | Free | Utilities | | [iFont: find, install any font](https://appshunter.io/ios/app/ifont-find-install-any-font/id1173222289) | 4.6 (12,929) | Free | Utilities | | [Count That Now - Tally counter](https://appshunter.io/ios/app/count-that-now-tally-counter/id955952873) | 4.7 (4,089) | Free | Utilities | | [Counter Tally Count](https://appshunter.io/ios/app/counter-tally-count/id1144352844) | 4.8 (13,324) | Free | Utilities | | [Sudoku Solver AI: Hints](https://appshunter.io/ios/app/sudoku-solver-ai-hints/id1450071180) | 3.0 (2) | Free | Utilities | | [Sudoku Puzzle Solver](https://appshunter.io/ios/app/sudoku-puzzle-solver/id1527437039) | 4.7 (18) | Free | Utilities | ## More apps by Atsuo Kazama - [R2o式わりかん電卓](https://appshunter.io/ios/app/r2o/id1442822892) - [R2o式 出欠管理表](https://appshunter.io/ios/app/r2o/id1449111484) - [MochimonoList](https://appshunter.io/ios/app/mochimonolist/id1492480277) - [I KU RA ?](https://appshunter.io/ios/app/i-ku-ra/id1499341953) - [The cheapest toilet paper!](https://appshunter.io/ios/app/the-cheapest-toilet-paper/id1507398025) All apps by Atsuo Kazama: https://appshunter.io/developer/1442822891 ## Related topics [atsuo kazama](https://appshunter.io/ios/topics/atsuo-kazama) · [r2o](https://appshunter.io/ios/topics/r2o) · [dwello](https://appshunter.io/ios/topics/dwello) · [r2logistics](https://appshunter.io/ios/topics/r2logistics) --- *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 2026-08-11.*