Games Like Sudoku — Free Logic Puzzles Online

If you love Sudoku, these games will feel familiar. They share the same core mechanic — fill a grid using constraints and deduction — but each adds a new twist. Free, no ads, no account needed.

Sudoku with cage sum constraints. All standard Sudoku rules apply, but the grid starts completely empty — cages replace given digits. Forced combinations like "2-cell cage summing to 3 must be {1,2}" provide a new deduction layer.

Play Killer Sudoku →

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Kakuro

Number crossword

The number crossword. Fill white cells with digits 1–9 so each run sums to its clue, no repeats within a run. The intersection logic is identical to Sudoku scanning, but the arithmetic layer makes it harder and more rewarding.

Binary Sudoku. Same grid, same row/column constraint logic, but you only place two values (0 and 1) instead of nine. Much faster than Sudoku — Easy solves in under 2 minutes, Hard in 10–15.

Turn all the lights off. Every click toggles a cell and its orthogonal neighbours. Like Sudoku, the correct solution is reachable by pure logic — but the constraint structure is entirely different and surprisingly tricky.

Play Lights Out →

How are these games similar to Sudoku?

All of them share Sudoku's core design principle: a grid puzzle with a unique solution reachable by logical deduction. No guessing required. If you can solve Sudoku, you already understand the mindset these games require.

Which game is the most like Sudoku?

Killer Sudoku is structurally closest — it uses the same 9×9 grid and the same row/column/box rules. The cage constraints add arithmetic on top. If you've mastered Hard Sudoku, Killer Sudoku Medium is a natural next challenge.

Which is harder — Sudoku or Kakuro?

Generally Kakuro. Sudoku requires positional logic only. Kakuro requires both arithmetic reasoning (combination analysis) and positional logic simultaneously. Most players find Easy Kakuro comparable to Medium Sudoku in difficulty.

What are the best free Sudoku alternatives?

Killer Sudoku is the closest direct alternative. Binairo is faster and easier to learn. Kakuro is harder and more rewarding for experienced Sudoku players.

Do I need to know Sudoku to play these games?

No. Each game explains its own rules. Sudoku experience helps with Killer Sudoku, but Binairo, Lights Out and Kakuro have entirely different rule sets.

Are these games free forever?

Yes — free, no account, no ads, no time limits. All games include global leaderboards and dark mode.