For players who know the rules and can find singles reliably.
Medium Sudoku online
The balanced daily challenge.
Medium Sudoku keeps direct logic in the mix but makes you connect more than one observation. It is ideal for regular practice: demanding enough to build skill, yet short enough for a focused break.
Balanced challengeCandidate practiceFree, no sign-up
Balanced scanning and notes34 clues
Combine scans across rows, columns and neighbouring boxes.
Keep short, accurate notes where several values remain possible.
Maintain a repeatable solving loop when progress slows.
What changes at Medium difficulty?
Medium Sudoku uses the standard 9×9 grid and the same row, column and 3×3 box rules as Easy. The difference is the path through the puzzle. Fewer placements are immediately visible, so you must revisit the grid after each move and compare information between units.
Many Medium puzzles still rely heavily on naked and hidden singles, but those singles may appear only after candidates are updated elsewhere. You may also encounter simple pairs or locked candidates. The challenge is less about memorising advanced names and more about keeping an accurate picture of what each empty cell can contain.
A practical Medium Sudoku workflow
- Collect the obvious singles first. Clear direct moves before writing many notes; they simplify the candidate map.
- Scan one digit through every box. Compare the rows and columns already containing that digit to locate restricted positions.
- Write candidates in unresolved areas. Focus on cells with two or three possibilities instead of filling the entire board automatically.
- Look for repeated pairs. If two cells in one unit contain the same two candidates, those values can be removed from other cells in that unit.
- Restart the scan after each breakthrough. A pair or locked candidate often produces a new single somewhere else.
Patterns to recognise
Hidden single
A digit has only one available location in a row, column or box, even when the cell has multiple notes.
Naked pair
Two cells share the same two candidates, reserving those numbers and eliminating them elsewhere in the unit.
Pointing pair
A candidate inside one box is confined to one row or column, so it can be removed from that line outside the box.
Box-line reduction
A candidate in a row or column is confined to one box, allowing eliminations from the rest of that box.
How to use notes without creating clutter
Candidate notes are a temporary model of the puzzle. They help only when they stay accurate. Begin by noting cells in a dense unresolved area, especially those with two possibilities. After every placement, remove the value from its row, column and box. Then look for a cell reduced to one candidate or a digit that now has one location in a unit.
If your board becomes crowded, pause entry and audit one unit at a time. Incorrect candidates are usually caused by missing a given digit or forgetting to update notes. Do not guess merely because several notes remain. Switch perspectives: scan a different box, follow one digit across the grid, or compare candidate positions in neighbouring boxes.
How Medium fits into a practice plan
Medium is often the best level for daily play because it rewards good habits without requiring a long advanced chain. Track clean completions rather than chasing a single fast time. A useful practice cycle is one untimed puzzle for technique, followed by one timed puzzle only after your candidate work feels stable.
Move to Hard when you can complete Medium without guessing and can identify why a candidate is eliminated. If you frequently lose the solving thread, return to the singles guide and practise pairs before increasing difficulty.
Medium Sudoku questions
How long should a Medium Sudoku take?
There is no required time. Familiar players may finish quickly, while careful learners may take much longer. A correct, explainable solve is a better benchmark than a universal minute target.
Is a hint a failed solve?
No. A hint can be a learning tool. Inspect the affected row, column and box to understand why the move works, then continue without rushing.
Why do I get stuck after a fast start?
The first singles simplify the grid, but the next step may require candidate comparison. Update notes, search for pairs and scan one digit across all boxes.
Written and reviewed by the SudokuGG editorial team against the current Medium game. Last reviewed July 21, 2026. See our editorial policy.