About Variadoku

What Variadoku is

Variadoku is a sudoku site for players who have done a lot of classic sudoku and want a different puzzle on the same idea. Every variant keeps the rule you know (no digit repeats in a row, column or region) and adds one more: sums on cages, towers seen from the edge, signs between neighbouring cells, odd and even cells, a board of triangles.

Every puzzle is generated on your device by the same solver that grades it, so the supply never runs out, and every puzzle can be solved by logic alone. No guessing is needed.

The variants

• Classic 9×9 Sudoku: Digits 1–9, one of each per row, column and box.
• 6×6 Sudoku: Smaller board: digits 1–6, boxes 3 wide and 2 tall.
• Difference Sudoku: Circles mark neighbours whose digits differ by 1.
• Irregular 6×6 Sudoku: Digits 1–6, with jigsaw regions instead of boxes.
• Odd/Even Sudoku: Pink cells take odd digits, white cells even.
• Relational 6×6 Sudoku: Every border says which neighbour is bigger.
• Killer Sudoku: Cages of distinct digits that add up to a given total.
• Windowed Sudoku: Outside numbers total the three nearest cells.
• Triangle Sudoku: Triangular board, with lines in three directions.
• Skyscraper Sudoku 5×5: Digits are towers; clues count what you can see.

Ways to play

• Endless tracks: one per variant, starting easy and getting harder level by level.
• The daily puzzle: the same puzzle for everyone each day, with a streak to keep — and the daily killer, a hard killer sudoku every day with a streak of its own.
• Free play: choose a difficulty and get a new puzzle at that grade.

There is no account to make. Your progress is kept in your own browser, and the site works offline once you've opened it. On a phone you can add it to your home screen and use it like an app.

Who makes it

Variadoku is made by Zoltan Parti. Bug reports, puzzle ideas and complaints are all welcome at support@variadoku.com, or see the contact page.