How to play Neon Sudoku
Neon Sudoku is the classic 9x9 number puzzle glowing in neon. Fill the grid so every row, every column and each of the nine 3x3 boxes contains the digits 1 to 9 exactly once. Pick a difficulty — Easy, Medium or Hard — and press Start to generate a brand-new puzzle with a guaranteed unique solution, so every game is fair and solvable by pure logic.
Controls
Tap or click a cell to select it, then tap a number on the pad to place it. On desktop you can type digits 1 to 9 directly, use Backspace or 0 to erase, N to toggle notes mode, H for a hint, and the arrow keys to move your selection around the board. Notes mode lets you pencil small candidate numbers into a cell, which is essential for harder puzzles.
Tips & strategy
Start by scanning rows and boxes that are nearly complete — the missing digits reveal themselves. When a digit can only go in one spot within a box, lock it in. Turn on notes mode and pencil every candidate into empty cells; when a cell has just one note left, that is your answer. Avoid guessing: three mistakes end the game. If you are stuck, use a hint sparingly — it reveals one correct cell but you only get three per game.
Scoring
Your score is your solve time, shown live on the timer. Finish a puzzle with fewer mistakes and a faster clock to beat your best time, which is saved separately for each difficulty level. Harder puzzles earn bigger bragging rights — the real challenge is cracking Hard with zero mistakes.