A classic logic puzzle. Three difficulties, notes mode, error checking. Plays entirely in your browser — your puzzle never leaves your device.
This is a free Sudoku game that plays right in your browser — no app, no sign-up, nothing saved to a server. Pick a difficulty, select an empty cell, and enter a digit 1–9; start a new puzzle whenever you like. Use it to unwind, sharpen focus, or pass a few minutes.
Fill the 9×9 grid so every row, every column, and each of the nine 3×3 boxes contains the digits 1 through 9 with no repeats. Every puzzle has exactly one solution reachable by logic alone — no guessing required.
Scan for rows, columns, or boxes that are already crowded with numbers; their empty cells have the fewest possibilities. Pencilling in candidate digits for each open cell, then eliminating, is the core technique that unlocks the rest.
Easy puzzles start with more given numbers and solve with simple scanning; harder levels remove more givens and require advanced techniques like spotting hidden pairs or candidate chains. The solution is always unique regardless of level.
No — it's free and runs entirely in your browser, so your puzzle never leaves your device and there's no account to create. Refresh or start a new game anytime.
They're solid practice for focus, patience and logical reasoning, and many people find them genuinely relaxing. Honestly, research suggests they keep you sharp at that style of puzzle rather than raising general intelligence — but as low-stakes mental exercise they're great.