How to use the chess clock
- Choose a time control such as Blitz 5+0, Blitz 3+2 or Rapid 15+10, or set custom minutes and increment.
- Place the phone or tablet between the players. Black taps first to start White's clock (or either player taps their own side to begin).
- After each move, tap your own clock to stop it and start your opponent's. Space works on a keyboard.
- Pause with ⏸ and reset with ↺. When a player's time runs out, their side turns red and a tone sounds.
Increment and delay explained
Time controls are written as minutes + seconds, like 3+2: three minutes each, plus a bonus per move. With a Fischer increment, the bonus is added after every move, so a player can build up time by moving quickly; this is standard in online and most over-the-board tournaments. With a Bronstein delay, you get back the time you used up to the delay amount, so your clock never gains time. With a simple delay (US delay), the clock waits for the delay before it starts counting down. Under 10 seconds, the display shows tenths so you can see exactly how close it is.
The clock is driven by the browser's high-resolution timer and calculates remaining time from timestamps, so it stays accurate even if the device is busy. It works for chess, Go, Scrabble, debates and any two-player game with a time limit. Everything runs locally in your browser.
What does 3+2 mean?
Three minutes per player, plus two seconds added after each move.
Who starts the clock in chess?
Black starts White's clock at the beginning of the game.
Can I use it for other games?
Yes. Any two-player game with turns, such as Go, Scrabble or debate rounds.