Mastermind

Play free online — no downloads, no installs.

About Mastermind

Mastermind is the classic free online code-breaking game. A secret code of four colours is hidden; you guess, and after each try you get clues — a filled dot for a colour in the right place, a hollow dot for a right colour in the wrong place. Use the feedback to deduce the code in as few guesses as possible, within ten tries. Simple rules, deep logic, and playable on phone or desktop with no download and no sign-up.

How to play

Open with two guesses that test different colours to learn which ones are in the code before worrying about position. Remember: a hollow dot means the colour belongs somewhere else, so move it on your next try. Track what each clue rules out — good deduction usually cracks it in five or six guesses.

Frequently asked questions

Is Mastermind free to play?
Yes — Mastermind is completely free to play online in your browser, with no download, no installs and no sign-up.
How do you play Mastermind?
Pick colours from the palette to fill the four slots of your guess. Tap a placed peg to remove it; press Check when the row is full. Read the clues beside the row: a filled dot = right colour, right spot.
Can I play Mastermind on my phone?
Yes — Mastermind works on phones, tablets and computers. It runs in the browser, so there is nothing to install.
Any tips for Mastermind?
Open with two guesses that test different colours to learn which ones are in the code before worrying about position. Remember: a hollow dot means the colour belongs somewhere else, so move it on your next try. Track what each clue rules out — good deduction usually cracks it in five or six guesses.