GOMOKU
GOMOKU is a free five-in-a-row game on a 15x15 board where you play the AI or a friend and climb from 18 kyu to 9 dan, right in the browser.
You play black and move first. Connect five stones horizontally, vertically or diagonally to win, and a gold line is drawn through them. Neither side may play a double-three, so a red X appears on those points. If the board fills up, it is a draw.
You start against an 18 kyu opponent. Win and NEXT takes you up one rank; lose and you play that rank again. Higher ranks read further ahead, and the high dan ranks find wins built from threes and fours in a row. From 1 dan you switch between black and white every game. Your rank stays saved in the browser.
Block the opponent's four for NICE, or threaten two wins at once for GREAT. Press 2 PLAYERS on the title screen and two people take turns on one phone or PC.
- Type
- Board game · Gomoku
- Built in
- 1 day
- Made with
- Canvas 2D · alpha-beta search AI
- Status
- Complete · 27 ranks · 2-player mode
- Released
- 2026-09-13
- Last updated
- 2026-09-13
Good for — anyone who wants a Gomoku opponent at any hour, people looking for a Gomoku site with no app, and two people with one phone.
Frequently asked questions
What are the controls?
Tap or click where two lines cross to place a stone. On a phone, the row and column under your finger light up and the stone goes down when you lift your finger. On a PC, a faint stone shows where the mouse is.
What are the rules?
Black moves first. The first player to connect five stones of their color horizontally, vertically or diagonally wins, and six or more also counts. Neither side may play a double-three, a move that makes two open threes at once; a red X appears if you try. A move that blocks the opponent's four is allowed even if it makes a double-three, and four-four and four-three are allowed too. If the board fills up, the game is a draw.
How strong is the AI? Can a beginner win?
There are 27 steps, from 18 kyu through 1 kyu up to 9 dan. The 18 kyu opponent often overlooks your threes, so knowing the rules is enough to win. Higher ranks read further ahead, and the high dan ranks find wins built from threes and fours in a row. Because black moving first has a big edge, from 1 dan you switch between black and white every game. They are steps of opponent strength inside this game, not official ranks.
Can two people play, or play online?
Two people can play. Press 2 PLAYERS on the title screen and take turns on one phone or PC. There is no online play between different devices.
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