Chess Clock

About the Chess Clock

This free online chess clock turns a phone, tablet or laptop into the two-sided clock you put beside a board. Each player has their own time. You press your own half when your move is finished, which stops your clock and starts your opponent's.

It works for any two-player game with a time limit — chess, shogi, go, draughts, Scrabble, backgammon, or a debate where each side gets equal time.

Everything runs in your browser, so it keeps working with no internet once the page has loaded.

Increment and delay

These are the two ways of stopping a game from being decided purely by who can move their hand faster.

• Increment (Fischer) — a fixed number of seconds is added to your clock each time you complete a move. With 3+2, every move you make gives you two seconds back. Play quickly enough and your time can go up.
• Delay (Bronstein) — each move gets a few free seconds before your clock starts running down. Move inside the delay and you lose nothing, but you can never gain time either.

Increment is the common choice online and in most modern tournaments. Delay is more usual in over-the-board play in some federations. Set either to 0 if you want a plain countdown.

The presets

• Bullet 1+0 — one minute each, no increment. Very fast.
• Blitz 3+2 — the most played online blitz setting.
• Blitz 5+3 — a little more room to think.
• Rapid 10+5 — long enough for a real game, short enough for a lunch break.
• Classical 30+20 — club-evening length.

Pick Custom to set your own minutes, increment and delay.

Why the top clock is upside down

The two players sit facing each other across the board, so a screen lying flat between them is the right way up for only one of them. The top half is rotated 180° so both players read their own clock the right way up.

Put the device flat on the table between you, press Full screen, and it behaves like a real clock.

Features

• Increment (Fischer) and delay (Bronstein), separately adjustable
• Five presets from bullet to classical, plus custom times
• Move counter for each player
• Tenths of a second shown under ten seconds, when it matters
• A warning beep at 30 seconds, and a low tone when the flag falls
• Pause and reset without losing your settings
• Full screen, with the top half rotated for the player opposite
• Arrow keys on a computer — left for player 1, right for player 2
• Your last settings are remembered in this browser

Good to know

• Time is measured against the real clock, not counted down frame by frame. If your browser throttles the tab in the background, nobody gains free seconds.
• Only the player whose clock is running can press. Pressing the other half does nothing, which prevents the usual accidental double-tap.
• The first press starts the opponent's clock, exactly like a mechanical clock: White presses, Black's time begins.
• Keep the screen from sleeping during a long game — most phones have a setting for this.
• This is a clock, not an arbiter. It does not know the rules of your game, and it does not record moves.

How to use it

• Choose a preset, or set the minutes, increment and delay yourself
• Press Start, then press Full screen and put the device between the players
• The player who moves first presses their own half when their move is done
• Each player presses their own side after every move
• Use Pause to stop everything, and Resume to carry on
• Press Reset for another game with the same settings