How to use the chess clock
- Pick a preset such as 5 minutes or 15 minutes plus 10 seconds, or type your own minutes and increment in seconds.
- Press Start. White's clock begins to run. Turn the top clock upside down with the checkbox if you are sitting across from each other.
- After each move, tap your own side of the screen or press the Space bar. Your clock stops, your increment is added, and your opponent's clock starts.
- Use Pause if you need to stop the game and Reset to start over with the same time control. When a clock reaches zero, the tool says whose time ran out.
How the clock works
Each player has their own time. Only the clock of the player whose turn it is runs. Pressing your side after you move stops your clock, adds your increment, and starts the other one. The first press starts White's clock, the way a game starts when the first move is on the board. Time is measured from the device clock rather than by counting ticks, so it stays correct even if the tab is in the background or the display slows down.
Time controls
A time control is the base time each player gets plus an optional increment added after each move. Common examples are shown in the preset list.
- Bullet games are about 1 minute each.
- Blitz games run from 3 to 5 minutes each, often with a small increment.
- Rapid games run from 10 to 30 minutes each.
- Classical games are longer, such as 90 minutes with a 30 second increment.
Other games and limits
The clock works for any two player game with turns, including shogi, checkers, Scrabble, Go and board games with a speed limit. It does not play a sound, because sounds are not needed for the clock to work, and it does not keep a record of games. It does not support delay or Bronstein time or multiple stage controls. For a single countdown see the online timer, and for a stopwatch use the stopwatch.
Assumptions and limits
- The time control is the same for both players. Minutes can be fractions, such as 0.5 for 30 seconds.
- The increment is added after a player completes a move, the style used for Fischer increment.
- The clock runs in your browser tab only and is not saved. Closing or reloading the page ends the game.
- Nothing is uploaded and no game data is stored anywhere.
Frequently asked questions
What does increment mean on a chess clock?
An increment is time added to a player's clock after each move. With 5 minutes and a 3 second increment, you gain 3 seconds every time you finish a move, so you cannot lose all your time just by playing steadily.
Does the clock keep running if I switch tabs?
Yes. It measures real elapsed time from the device clock, so the numbers are correct when you come back. The display may update less often while the tab is hidden.
How do I start a game?
Choose a time control and press Start. White's clock begins at once. After White moves, White taps their side and Black's clock starts.
Can I use it with a different time for each player?
Not in this version. Both players get the same base time and increment, which is the standard for most games.