Take White against a see-through chess engine with adjustable depth, move hints, and a live advantage bar.
Chess vs Computer gives you the white pieces against a compact engine written in JavaScript. You move, the engine takes a moment to think, and Black replies. As always, the aim is to checkmate the enemy king.
What makes it unusual is how much it shows you. After each reply you can see how many positions the engine looked at, how long it spent, and how many positions it checked per second. A bar beside the board tracks who is ahead.
Getting started
Full chess rules are in place, castling and en passant included. Drag one of your pieces to its new square and release it. An illegal move simply snaps back. With a mouse, hovering over a piece shades every square it can legally reach.
Your latest move is outlined in yellow and the engine’s answer in blue, which makes it easy to follow the game. One rule differs from tournament play: any pawn that reaches the final rank always becomes a queen, for both sides.
How the engine thinks
Under the hood, the computer runs a minimax search trimmed by alpha-beta pruning. It judges positions by the value of each piece and by where pieces stand on the board. Under Settings you can set Black’s search depth anywhere from 1 to 5, with 3 as the default. A deeper search plays far more carefully but takes longer, and the page waits while it calculates.
The Advantage reading is the engine’s own score. A sudden swing after your move usually means you left something unprotected.
Strategy notes
- Begin at depth 2 and only climb once you are winning there regularly.
- Use the Opening Positions menu to jump straight into the Ruy Lopez, the Italian Game or the Sicilian Defense, then practice the middle game that follows.
- Undo removes your move and the engine’s reply together, and Redo replays them. Try an alternative and watch how the bar reacts.
- Because promotion is always to a queen, check for stalemate tricks before pushing a pawn to the end.
Who it suits
This is a good fit for players who want to understand a chess engine rather than just lose to one. Beginners can stay at low depth and lean on hints. Stronger players can crank the depth to 5 and use the search stats to see how hard the computer is working.
Controls
| Action | Mouse | Touch |
|---|---|---|
| Move a piece | Drag the piece to its new square | Drag the piece to its new square |
| Preview legal moves | Hover over one of your pieces | — |
| Take back your last move and the reply | Click "Undo" | Tap "Undo" |
| Replay moves you took back | Click "Redo" | Tap "Redo" |
| Change engine depth or turn on hints | Open "Settings" and pick a value or tick the box | Open "Settings" and pick a value or tick the box |
| Load an opening or restart | Open "Opening Positions" and click a button | Open "Opening Positions" and tap a button |
Chess vs Computer FAQ
Can I play Chess vs Computer on a phone or Chromebook?
A Chromebook or laptop is the most comfortable, since you drag pieces with the trackpad and can hover to preview legal moves. On a phone you can drag pieces with a finger, but on a narrow screen the menus sit on top of the board, which means scrolling down inside the game to find it.
Is it one or two players?
It is built for one player against the engine, and you always take White. There is also a Computer vs. Computer mode where the engine plays itself, with a separate depth setting for the White side.
What should I do when I am stuck?
Open Settings and tick "Show Suggested Move (White)". A red outline then marks where the move the engine likes best for you begins and ends. Treat it as a second opinion, and use Undo if you want to test a different idea.
How does a game end?
Checkmate wins it. The Status line also reports draws by stalemate, a position repeated three times, fifty moves without progress, or too little material left to force mate, and it warns you whenever a king is in check.
