Sudoku
Every row, column, and 3×3 box holds 1–9 exactly once.
Why Sudoku is in Kefiw Daily
What it trains
Sudoku is a structured attention drill. The useful work is scanning rows, columns, and boxes, then making a small certain placement instead of guessing.
How scoring works
Faster completed grids rank higher, but clean logic matters more than speed. A steady solve usually beats a rushed board with contradictions.
Privacy
The grid and progress live in local browser state. Leaderboard submission is optional and separate from solving the puzzle.
Use it with
Pair Sudoku with Kefiw Spatial when you want a short routine that mixes logic, visual scanning, and pattern recognition.
How to make the practice useful
If the grid stalls, review the last certain placement instead of jumping to a guess. Ask which row, column, or box made that number unavoidable. That habit trains constraint checking, the same skill behind clean planning decisions: reduce the possible choices, place the one supported answer, then rescan the board after the situation changes. Speed is useful only after that logic is clean.