Candidate mode
Sudoku with Auto Candidates
Use automatic candidate marks to keep possible numbers visible while you solve harder puzzles.
Read the guideFeatures
Sudoku features for cleaner solving
Ruedoku is built for people who want a simple free Sudoku board with practical help when the puzzle gets busy. These guides explain the built-in hints, candidate mode, and pencil mark workflow.
Learning mode
Sudoku with Hints
Get hints that explain the solving move, not just the answer, and use Auto Play to study the next step.
Read the guidePencil marks
Sudoku with Pencil Marks
Track notes manually, toggle candidates from the keyboard, and avoid guessing in medium and hard puzzles.
Read the guideStart with candidates enabled
If you already know the rules, open a puzzle with candidate marks visible and use the Hint button when you want the next logical move explained.
Play free Sudoku