Code-breaking puzzle game. Guess the secret color code with feedback pegs. Three difficulty levels
Crack a secret color code using logic and deduction. After each guess, you receive feedback telling you how many colors are correct and how many are in the right position. Can you break the code within the allowed attempts?
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Sudoku puzzle generator and solver with auto-generated valid puzzles, hint system, and error highlighting
Classic minesweeper with right-click flagging, timer, first-click safety. Beginner, Intermediate, Expert modes
Slide numbered tiles to combine and reach 2048! Features touch/swipe support, undo functionality, and score tracking
Your guess gets two black pegs and one white peg of feedback.
Guess + feedback
R G B Y → ●● (right colour+spot) ○ (right colour, wrong spot)
Deduction
Exactly 3 of these 4 colours are in the code; one is correctly placed-count known
Black = right colour and position, white = right colour wrong position; combining feedback across guesses lets you deduce the code logically. Knuth’s strategy proves any code is solvable in five guesses or fewer with disciplined elimination.
Crack a secret color code using logic and deduction. After each guess, you receive feedback telling you how many colors are correct and how many are in the right position. Can you break the code within the allowed attempts?
Each game is a structured deduction exercise that sharpens analytical thinking.
Forming hypotheses and testing them against feedback mirrors real scientific inquiry.
The elimination logic in Mastermind maps directly to debugging and constraint-solving skills.
Race a friend to see who can crack the code in fewer guesses.
Mastermind rewards systematic thinking. Each round of feedback narrows the possibilities, and experienced players use elimination strategies to solve most codes in four or five guesses. It is one of the best logic puzzles for developing deductive reasoning skills.
The default is 10 attempts, but you can adjust the difficulty for more or fewer.
Black peg = correct color in the correct position. White peg = correct color but wrong position. No peg = that color is not in the code (for that slot).
Yes. With optimal strategy, any code can be cracked well within the default guess limit.
The game runs entirely in your browser. No account is needed and no gameplay data is collected.