Sudoku Sprint

Sudoku Sprint is a free online sudoku game built for speed and set in a calm zen garden. Instead of one big 9×9 puzzle that takes half an hour, you get three mini sudokus in a row, each a 6×6 grid of carved stone tiles on raked sand, and one clock for all of them. Fill every row, every column and every 2×3 box with the numbers 1 to 6, each exactly once, then move straight on to the next grid. It is the classic number puzzle you know from newspapers, cut down to a quick sudoku game you can finish on a coffee break, in your browser, with no download and no sign-up.

A run starts with a warm-up grid of 20 clues, where the next number is never hard to find. The second grid gives you 17 clues and fewer obvious moves. The third grid has only 14 clues and one moment where no number can be placed until you spot a locked candidate: a number that must sit in one row or column of a box, which rules it out everywhere else in that line. Every 6x6 sudoku in the game has exactly one solution and can be solved by pure logic, without guessing, and every grid of the same level is equally hard, whichever puzzle you are dealt.

The clock is what makes it a sprint. You have just under two minutes for all three grids, and the clock keeps running between them. Every right number scores 100 points, and if you keep a flow going, placing each number within three seconds of the last, the third in a row is worth double and the sixth triple. A grid solved without a single mistake earns a clean bonus of 500 on top of the 1,000 every solved grid is worth. A wrong number cracks red, shows you the stones it clashes with and costs five seconds, so guessing is allowed but expensive. Stuck for ten seconds? The hint button lights up and sets one stone for you, for no points. Solve all three sudokus and every second left on the clock is worth 120 bonus points.

Because the game has a finish line it also has a fastest-clear leaderboard, which makes it one of our speedrun games as well as one of the puzzle games and sudoku games. The board ranks the real time from the first tap to the end of the short finish after your last stone, and every ranked run is replayed on our servers before it counts. Mistakes and hints do not change that time directly, but they shrink the clock, the bonus and your score.

The controls are made for touch. Tap a square and its row, column and box light up, along with every stone that holds the same number; tap a number on the stone pad first and every stone of that number glows, which makes scanning by number one tap. Notes switches the pad to pencil marks and Erase clears a red number or the marks. On a computer, click the same way or play with the keyboard: the arrow keys move the selection, the number keys 1 to 6 enter numbers, Backspace or Delete erase, Space toggles notes and H takes the hint. It plays just as well on mobile as on a PC.

If you enjoy logic puzzles with numbers, Sudoku Sprint sits alongside the other number games and the short challenges on the brain games page. A full run lasts two minutes at most, so it is also one of our quick games and a good pick among the free games to play at work. New to sudoku? The mini grid is the friendliest way to learn it, the first grid is easy enough to finish on your first try, and a few runs are enough to start seeing the patterns.