Sudoku Master

Sudoku Master packs the classic 9x9 logic puzzle into a clean browser format with several difficulty tiers — from an easy grid for a morning warm-up to an expert setting where pencil marks stop being optional. There's no clutter around the edges: a plain grid, legible numbers, and exactly the tools a solver actually needs.

The rules are the standard ones: fill every row, column, and 3x3 block with the digits 1 through 9 with no repeats. Click a cell to select it, then click a number on the side panel to fill it in, or long-press a cell to switch it into pencil-mark mode for tracking several candidate digits at once. A hint button points to a cell where the logic is already fully determined whenever you get stuck, and an undo button rolls back the last entry without resetting the whole board. A small timer in the corner tracks each session for players who like racing their own best times.

The game works for beginners still learning sudoku logic on the easy tier, and for veterans hunting the kind of hard, newspaper-puzzle-page grids that actually take real deduction. It doubles as a daily brain warm-up for memory and focus, and easy-tier rounds are short enough to finish in a five-minute break. Harder grids are easier to manage on a full screen, where it's simpler to keep several rows of pencil marks in view at once. Tip: before guessing a digit, scan the full row and column for a cell where only one number is logically possible — that's almost always faster than a random guess that might need backtracking later.