Play Othello Online Against the Computer

A board, two colors, and a different decision every turn

Othello online: a place to learn by playing

Othello is a strategy board game in which each move can change the color of several discs. You and the computer share an 8 by 8 board, taking turns to place a disc and flip opposing lines. The goal is to finish with more discs of your color when neither side can move. An early lead is only a snapshot: a handful of well-timed moves can reverse a large part of the board.

This version is designed for playing against the computer on your own. There is no opponent queue, account form or installation step. Load the page, choose a difficulty and select one of the marked squares. The computer calculates its reply in your browser. That makes it useful for a quick break or for repeatedly practicing the same opening without waiting for another player.

How to play Othello in this browser

1. Choose your starting level. Easy is useful when you are learning which moves are legal. Medium adds positional choices, while Hard looks further ahead. The new-game selector above the board starts a fresh position at your selected difficulty. The menu beside the board lets you change levels during play, with confirmation before an unfinished game is discarded.
2. Play a marked empty square. You control Black and take the first turn. A move must trap at least one opposing disc between your new disc and another black disc in a straight line. Hint dots show legal squares. They do not rank the moves or promise that a particular square is strategically best.
3. Watch the complete reply. All lines captured by your placement flip automatically, then White responds. Read the turn indicator before choosing again. If one side has no legal move, its turn passes automatically. It can be correct for the same player to move twice in succession; this does not mean the other color has disappeared from the game.
4. Review a decision with Undo. In this human-versus-computer game, Undo returns to an earlier position where you can choose a move. It usually removes your previous placement and the computer's reply. When passes occur, the number of steps taken back may differ. Try an alternative and compare the resulting choices.
5. Count at the end. When both sides are unable to place a disc, the game is over. The larger on-board disc count wins and equal counts produce a draw. Use New game to practice again, or open Stats to review the results stored in this browser.

Pick an Othello computer difficulty that suits your practice

Hard searches up to six plies, meaning six alternating placements in the search tree rather than six complete pairs of turns. Its search is capped at approximately 1.5 seconds; animation and scheduling can add visible time. A reply can finish earlier, and the deepest completed search can vary by position and device. These settings are implementation limits, not tournament ratings. None of the three options is presented as an unbeatable or perfect-play opponent.

Try a real opening example

The board starts with White at D4 and E5 and Black at E4 and D5. At this position Black has four legal first moves: C4, D3, E6 and F5. Choose D3 to see a vertical capture. D4 lies between the new black disc at D3 and the existing black disc at D5, so D4 changes from white to black.

The visible count becomes four black discs and one white disc. After White answers at C3, the diagonal through D4 to E5 is bracketed, and D4 turns white again. The count then becomes three discs of each color. You can reproduce this two-placement sequence on a physical board. In the live game the computer chooses its own reply, so it is not required to choose C3. Use the example to understand the rule, not as a prediction of its move.

The important detail is that the disc never moves to another square: only its visible color changes. A single placement may capture horizontally, vertically and diagonally, but newly flipped discs do not start a separate chain of captures. For diagrams and answers about unusual positions, use the Othello rules and common questions guide.

A focused practice routine for beginners

For your first game, ignore the score until you understand why each marked square is legal. Before clicking, trace one line from the intended move to a black disc already on the board. Identify exactly which white discs are between them. After your placement, compare your prediction with the animation. This small habit builds a clearer understanding than clicking every available square as quickly as possible.

For your next game, check corner access before counting flips. Corners cannot be captured back, because there is no square beyond them from which to complete a bracket. A move near an empty corner can offer the opponent an entry. However, an edge is not automatically safe and a square beside a corner is not always forbidden. Look at the actual legal reply rather than treating a square's location as a complete strategy.

Once that feels comfortable, compare two candidate moves by the choices they leave your opponent. This is the idea of mobility. A move that flips fewer discs may preserve more options for later. It is still possible to choose a bad move that flips very little, so do not replace one rigid rule with another. Ask what your opponent can do next and which choices you would have afterward.

Near the finish, change your question again: what final counts follow from the remaining moves? Include forced passes when counting a sequence. General ideas such as corner control help you choose candidates, but an exact final count is more useful than a positional rule when you can see the rest of the game. A loss can be a useful result if you can identify one decision you would now make differently.

Controls, local results and browser behavior

Use a mouse or tap to select a legal square. The board also exposes buttons to keyboard users; use Tab to reach available moves and Enter or Space to activate them. Keyboard shortcuts include N for a new game, U for undo, L for local statistics, H for the tutorial and M to toggle sound. Sound is optional, and the game can be played with it muted.

Stats records completed results locally. This is a personal practice record, not a worldwide leaderboard or an account that synchronizes across devices. Changing browsers or clearing this site's storage can remove that record. A browser refresh starts a fresh board rather than restoring the unfinished game, so finish a position before reloading if you want to keep playing it.

AI decisions run on your device; they do not require a paid language-model service. You still need to load the page and its resources. There is no offline installation or guaranteed disconnected reload. The current version does not include live multiplayer, chat, a rating ladder or timed tournaments. Those are different experiences from this single-player practice board.

Othello online questions