A chess clock on any phone or computer
This online chess clock turns a phone, a tablet or a laptop into a tournament clock for two players. Each player has a half of the screen with their remaining time in large numbers. After your move, tap your half: your clock stops and your opponent’s starts. The clock that is running turns white, so both players can see at a glance whose turn it is.
Set the phone flat between the two players: the screen splits into a top half, turned upside down for the player across the table, and a bottom half. On a computer or a phone in landscape, the halves sit side by side. There is nothing to install, no account, and the page keeps the screen on during the game.
How to use the chess clock
- Choose the time control. Tap a preset at the bottom of the screen, or turn the two wheels in the sentence: minutes per player, then seconds added per move.
- Start the game. In casual games, the player with Black taps their half to start White’s clock. In tournaments, the arbiter starts White’s clock.
- Tap after each move, with the same hand you used to move the piece. Your increment is added at that moment.
- Pause with the middle button if you need to stop both clocks, then press it again to resume.
- Time is up when a clock reaches zero: that half stays white, the bell rings and both clocks stop. The reset button prepares a new game.
Each half also counts the moves of its player. On a computer, the space bar presses the clock of the player whose time is running, and P pauses the game.
Time controls explained
A time control is written as two numbers: 3+2 means 3 minutes per player, plus 2 seconds added after each move. Here are the presets of this clock:
| Time control | Usual name | Under FIDE rules | Time per player for 40 moves |
|---|---|---|---|
| 1+0 | Bullet | Blitz | 1:00 |
| 3+2 | Blitz | Blitz | 4:20 |
| 5+0 | Blitz | Blitz | 5:00 |
| 10+0 | Rapid (online) | Blitz | 10:00 |
| 15+10 | Rapid | Rapid | 21:40 |
The FIDE Laws of Chess define two fast categories. Blitz: 10 minutes or less per player. Rapid: more than 10 and less than 60 minutes. With an increment, the rule adds 60 times the increment to the base time: 15+10 counts as 25 minutes. Online sites sort games a little differently. Chess.com estimates a 40-move game, base time plus 40 times the increment, and calls bullet anything under 3 minutes, blitz from 3 to under 10, and rapid 10 minutes and up.
Increment and delay
The increment you set is a Fischer increment, named after the world champion Bobby Fischer. He filed a patent in 1988, granted in 1989, for a digital clock that adds a few seconds after each move. The idea ended the sad sight of players losing a won position on time: as long as you move faster than the increment, your clock goes up. Under FIDE and US Chess rules, it applies from the first move. On this clock, the seconds are added when you press after your move, as long as your time has not run out.
Some clocks offer a delay instead: with a simple or Bronstein delay, the first seconds of each move are free, but unused seconds are not saved for later. This clock uses the increment only, which is what most tournaments and online games use today.
The clock rules, in short
From the FIDE Laws of Chess, in force since January 1, 2023:
- Same hand: a player must press the clock with the same hand that made the move, and must not keep a finger on it or hover over it (Article 6.2.3).
- Flag fall: a flag is considered fallen when the arbiter sees it, or when a player makes a valid claim (Article 6.8).
- Out of time: the player whose time runs out loses, except when the opponent cannot checkmate by any series of legal moves, for example with a lone king. Then the game is a draw (Article 6.9).
This clock stops at the first flag. It is up to the players to apply the draw rule by looking at the board.
Managing your time
- Divide your time by about 40 moves to get a budget per move, then spend more in critical positions and less on obvious moves.
- Play known openings quickly and keep your reserve for the middlegame.
- Avoid time trouble: without increment, under a minute, even a won game is hard to finish.
- Use the increment in the endgame: moving in less time than the increment makes your clock go up.
- Look at both clocks: when your opponent is short of time, keep the position complex.
Not just for chess
Any two-player game with turns works with this clock: checkers, Go, Scrabble, or a debate where each side has the same speaking time. For a single countdown, use the online timer, and to measure a duration, the stopwatch.