Pick 4 colours and press Guess
| Tap the colours | Build a four-colour guess. |
| Guess | Submit it and read the clues. |
| New game | Generate a fresh hidden code. |
Code Breaker is the classic deduction game usually sold as Mastermind. A hidden code of four colours sits behind the screen, and you guess. After each attempt you are told how many of your colours are exactly right and how many are correct but in the wrong place. From those clues alone, you narrow the possibilities down.
There is no luck in it beyond the first guess. Every subsequent attempt should be chosen to eliminate as many remaining possibilities as it can, which makes this a genuine exercise in logical inference. A good player cracks most codes in four or five attempts; a careless one runs out of tries having learned very little.
Open with a guess that uses several different colours rather than four of the same. A varied first guess returns much more information, telling you which colours are in play at all before you start worrying about their positions.
Read the two clue types carefully. One tells you a colour is right and in the right place, the other that it belongs in the code but sits elsewhere. Confusing them wastes attempts, because the second kind means you should keep the colour but move it.
Change one thing at a time when you are close. If a guess scored well, alter a single colour or swap a single pair on the next attempt. That way any change in the clues tells you exactly what that one difference caused.
Keep track of what you have ruled out. A colour that produced no clues at all is not in the code anywhere, so never use it again. Systematically eliminating colours narrows the puzzle far faster than guessing new combinations at random.
One marker means a colour is correct and in the correct position; the other means the colour is in the code but somewhere else.
A limited number of attempts. Running out reveals the code and ends the round.
Depending on the round, yes, which is why a guess returning fewer clues than expected can still be informative.
Cracking the code in four or five guesses is strong play. Two or three usually means a lucky opening.
No. Code Breaker runs entirely inside this page, so it starts the moment the page opens. There is nothing to download, no plugin, and no account to create.