Classic 9×9 Sudoku
Solve a full Sudoku grid directly in your browser—no downloads required.
Core gameplay experience
Six difficulty tiers
Choose from Easy to Extreme across six calibrated levels for every skill level.
Timer + mistake tracking
Challenge your speed and accuracy with a live timer and clear error counter.
Notes, hints, and undo
Use pencil marks, request a hint, or undo a move to stay in control.
Keyboard, mouse, and touch
Fast input for desktop, smooth number pad interactions on mobile, and full touch support.
Modes & content entry points
Multiple play styles
Jump into Classic today, with Killer mode planned alongside Daily Challenge and tournaments.
Rules and strategy guides
Find clear explanations and solving tips to level up your Sudoku technique.
Layout, navigation, and interaction
Adaptive navigation
Top navigation with a “More” dropdown and mobile-friendly collapsible menus.
Three-column layout
Gallery left, game center, and insights on the right—collapsing to a single column on small screens.
Board highlights
Selected cells, conflicts, and candidate numbers are highlighted for fast visual feedback.
Control panel
Switch difficulty or language, view stats, and tap New Game or Hint with one click.
Tech & algorithm foundation
Lightweight front-end
Pure HTML, CSS, and JavaScript—no framework required.
Sudoku generation + solver
Backtracking-based generation with difficulty tuning ensures solvable, graded puzzles.
State & autosave
Error hints, save states, and continuity features make it easy to continue later.
Configurable and ready to expand
Difficulty tuning
Adjust puzzle hole counts with difficultyLevels for fine-grained control.
Mistake limits
Define fail conditions with a configurable maxMistakes setting.
Theme-ready styling
CSS variables make it simple to refresh the color palette.
Roadmap highlights
Killer Sudoku, accounts, leaderboards, and variant expansions are on the way.