Pure Sudoku!
A pure, clean classic Sudoku
Free · In‑App Purchases · Designed for iPad. Not verified for macOS.
This is a pure, clean Sudoku app, crafted with care by a Sudoku lover for fellow enthusiasts.
It’s mainly for casual games at the moment, but it still assumes you already know the basic concepts and rules of Sudoku:
- A horizontal line of 9 cells is called a “row”, a vertical line of 9 cells is a “column”, and each 3×3 group of cells is a “box”.
- Digits 1–9 must be placed in all cells, with no duplicates within any row, column, or box.
- At any moment, multiple digits might be possible for a single cell. You can add “pencil marks” (small digits) to help you infer the final answer by checking the pencil marks in surrounding cells.
For experienced users: this app currently supports techniques up to size-3 subsets (naked/hidden triples). More advanced techniques are actively under development, and future versions will include a “Professional Mode” designed for advanced players.
Key Features:
• Dual Keypads
- Keypads for entering answer digits and pencil marks are shown on the screen at the same time.
- This helps prevent mistakes caused by forgetting to switch between answer mode and pencil-mark mode.
• Auto-fill Pencil Marks
- By tapping the wand icon, you can fill pencil marks for all empty cells with one click.
- It only fills empty cells — if you’ve removed some pencil marks using a technique, don’t worry, it won’t overwrite your work.
- It’s also handy when your pencil marks get messy: just clear the cell and tap the wand again.
• Cross-hatching
- When you tap a cell, a set of crossing lines appears, shading out all rows, columns, and boxes affected by that digit. This makes it easier to spot the available cells for the selected digit.
- It’s useful in easy games, and at the beginning and near the end of puzzles of any difficulty.
• Highlight Digits
- When you tap a cell that contains a digit, all other cells with the same digit — including pencil marks — will be highlighted.
- This is useful for spotting “single-digit patterns” such as hidden singles and locked candidates.
• Progressive Hints
- All hints are shown step by step. They don’t just give you the solution — they also show you why it works.
- Except for simple “single” techniques, most hints follow an “observation → reasoning → conclusion” structure.
- To close the hint pad without applying it, just tap anywhere on the game board.
• Auto Pause
- When you leave the app for any reason, it will automatically enter pause mode and stop the timer.
- You can also manually pause a game from the game menu, but you don’t really need to — want to pause? Just jump back to your home screen or turn off your display.
- Opening a hint won’t pause the game, and you can’t pause while a hint is open anyway :D the time you spend on hints still counts toward your final time.
• Themes
- Supports both light and dark themes, as well as an “Auto” mode to follow the system appearance.
• Optional Timer and Mistake Count
- The timer and mistake count can be shown above the board, and you can toggle them anytime in Settings.
- They are completely optional and are just for your reference — there are no penalties for taking too long or making too many mistakes.
• Statistics for a Single Game
- You can toggle the simple statistics in Settings; they will show your time used, mistake count, and hint usage after you solve a puzzle.
- These are completely optional and just for your reference.
- They are separate from the timer and mistake count shown above the board — you can hide them during the game and still get the statistics afterward, or vice versa.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
Added learning links to docs.pure-sudoku.app for helping user learn Sudoku solving techniques.
The developer, Yanbo Liu, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Yanbo Liu
- Size
- 8.6 MB
- Category
- Puzzle
- Compatibility
Requires iOS 17.6 or later.
- iPhone
Requires iOS 17.6 or later. - iPad
Requires iPadOS 17.6 or later. - Mac
Requires macOS 14.6 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.3 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- In-App Purchases
Yes
- Full Access $9.99
- 30 Days Pass $0.99
- Copyright
- Copyright © 2025-2026 Yanbo Liu. All rights reserved.
