LogicNumbersPuzzleMadness

Odd-Even Sudoku (PuzzleMadness)

Sudoku where squares and circles mark which cells hold odd or even digits.

Every day: A new dated Odd-Even Sudoku puzzle every day, the same for every player, one for each difficulty (Easy, Medium, Hard, Tough and Mixed); completed puzzles score on monthly and all-time leaderboards and past days stay in the archive. New puzzle: Once a day (the site does not state the time).

Play Odd-Even Sudoku (PuzzleMadness) on puzzlemadness.co.uk
A completed Odd-Even Sudoku from PuzzleMadness's rules, with square and circle markers

PuzzleMadness posts a new Odd-Even Sudoku puzzle every day, the same grid for every player, at several difficulty levels. Normal sudoku rules, and squares marked with a square hold odd digits while squares marked with a circle hold even ones. Finished puzzles score points on the site's monthly and all-time leaderboards.

About Odd-Even Sudoku (PuzzleMadness)

Odd-Even Sudoku is a 9x9 sudoku with shape markers in some squares. A square marker means the digit there is odd (1, 3, 5, 7 or 9); a circle means it is even (2, 4, 6 or 8). The markers cut the candidates in half for the squares that carry them.

The daily page opens today's puzzle on its own, and its title carries the date (on 3 October 2026 it read "Daily Medium Odd-Even Sudoku Puzzle for Saturday 3rd October 2026 (Medium)"). There is a separate dated puzzle for each difficulty: Easy, Medium, Hard, Tough and Mixed. Past days stay in the archive, so a missed puzzle can be played later, and there is a print version and an image download of the grid. PuzzleMadness does not publish solutions: the site tells you when you have finished a grid correctly or made a mistake. Each completed puzzle adds to your total on the Odd-Even Sudoku monthly and all-time leaderboards, where only your best score on any one puzzle counts.

Count the markers along a row or box: since each line has five odd and four even digits, a line with four circles already has all its even squares located, and every other square in it is odd. That counting is often more useful than the markers one at a time.

PuzzleMadness is a British puzzle site with dozens of daily puzzle types in the browser, from many sudoku variants to logic grids such as Nurikabe, Hashi and Slitherlink. It is free to play and carries ads. A free account keeps track of the puzzles you have finished and puts your name on the leaderboards, and the badges next to usernames mark how many puzzles a player has completed.

How to play Odd-Even Sudoku (PuzzleMadness)

  1. Open the day's Odd-Even Sudoku page and choose Easy, Medium, Hard, Tough or Mixed.
  2. Note which squares are marked odd (square) and even (circle).
  3. Fill the grid so every row, column and 3x3 box holds 1 to 9 once, respecting the markers.
  4. Complete the grid to finish and score.

Tips

  • Each row, column and box has five odd digits and four even digits.
  • Once four even squares in a line are known, the rest of that line is odd.
  • Pencil in only odd or only even candidates in marked squares.

Questions

What do the squares and circles mean in Odd-Even Sudoku?

A square marks an odd digit and a circle marks an even digit.

When does the PuzzleMadness Odd-Even Sudoku change?

Once a day: each puzzle is dated, and the daily page opens the current day's grid. The site does not say at what time the new one appears.

Is PuzzleMadness Odd-Even Sudoku free?

Yes. You can play without an account; the site shows ads. A free account records which puzzles you have finished and enters your scores on the leaderboards.

Where can I find the answers?

PuzzleMadness does not publish solutions. It tells you when your grid is complete and correct, and when you have made a mistake.

Can I play earlier Odd-Even Sudoku puzzles?

Yes, older puzzles are in the archive, and puzzles completed on any day count toward that month's leaderboard.

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