Mastermind

Mastermind is a free code breaking puzzle you can play in your browser. Deduce a hidden color peg sequence using black and white hint pegs after each guess. Standard, Hard, or the shared Daily Code with unlimited replays.

Also known as: code breaker, color code game, bulls and cows

Free Mastermind online in your browser: guess the hidden color code with black and white peg feedback. Standard, Hard, or the shared Daily Code.

How to play Mastermind

  1. Standard: 4 pegs, 6 colors, duplicates allowed, 10 guess rows. Hard: 5 pegs, 8 colors, 12 rows. Daily Code uses Standard rules on a UTC-seeded code — unlimited replays, today’s best is kept.
  2. Pick a color from the palette, then tap each hole in the active row (or tap holes to fill with the selected color).
  3. Press Submit Guess when the row is full.
  4. Black hint pegs = right color and position. White = right color, wrong position. Empty = not in the code (duplicates are not double-counted).
  5. Four black pegs wins. Running out of rows loses and reveals the code.

Score = max(0, 10000 − 400 × rows used − 5 × seconds). Higher is better. Best is stored per mode; Daily keeps today’s best separately on this device.

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