A chess clock for over-the-board games, right on your phone
You are sitting at a real board and the only clock in the room is the one on the wall. This chess clock turns a phone or tablet into a proper two-player game clock: two big halves, a tap to end your turn, a move counter for each side, and the increment or delay your club or tournament uses.
It is separate from the on-screen chess game: this one only keeps time, so you play with a physical board and pieces. Place the phone between the players, leave “Face-to-face” on so Black can read the top clock, and tap your own half after each move.
How to use the Chess Clock
- Choose a time control: a preset such as Blitz 3+2, Rapid 10+5 or Classical 90+30, or type your own minutes. Black can have a different amount of time for handicap games.
- Pick the increment type and its seconds: Fischer, Bronstein, simple delay or none. For a classical control, set “extra time after move no.” (for example 40) and the minutes added then.
- Press Start. White’s clock runs first. After White moves on the board, tap the bottom half; Black’s clock then runs, and so on.
- Use Pause for an arbiter call or a break; both clocks stop until you press Resume. Reset returns to the starting time and unlocks the settings.
- When a clock reaches zero the flag falls: the half turns red, the phone beeps and vibrates (if your device allows it) and the clock stops.
Chess Clock features
Big tap halves
Each half of the screen is one giant button, so you can slap it without looking. Only the running side responds, so a stray touch on the idle half does nothing.
Three kinds of extra time
Fischer adds the increment after every move. Bronstein adds back the time you actually used, up to the delay. Simple delay holds the clock for the delay and loses any unused part.
Time bonus at a move number
Add minutes to a player’s clock when that player completes a chosen move, such as 30 minutes after move 40.
Accurate timing
The clock reads the system time on every update instead of counting ticks, so a busy phone cannot make it run slow.
Alarm and screen wake
A flag-fall beep and vibration, a mute switch, and a request to keep the screen awake while a game runs.
How the clock follows the Laws of Chess
The behaviour mirrors Article 6 of the FIDE Laws of Chess (checked on the FIDE handbook PDF on 30 October 2026; the copy online carries the 2009 wording of the article, which has not changed in these principles):
- White’s clock is started first at the time set for the game to begin.
- After making a move on the board a player stops their own clock and starts the opponent’s; the time spent between moving and pressing counts against that player.
- A flag falls when the allotted time for a player expires. The clock stops there and shows which side ran out; whether that loses the game depends on the position and the arbiter (for example, if the opponent cannot checkmate by any sequence of legal moves it is a draw).
- Time-delay mode: both players get main thinking time and a fixed extra time per move; the main time starts counting down only after the fixed time expires, and unused delay does not change the main time.
- The names Fischer increment and Bronstein delay are the usual clock-manufacturer terms. They are not defined in the Laws themselves, so confirm the setting with the event’s regulations.
Limits
This is a casual aid, not an approved tournament clock. It does not store your game, record moves or enforce handbook details such as move counting for the 40-move rule. A phone can lock, receive calls or lose power, so use an approved clock for rated events, and keep the screen awake setting on for long games.
Chess Clock FAQ
What is the difference between increment and delay?
An increment adds time to your clock after you move, so you can bank it. A delay gives a fixed number of seconds before your main time starts to run each move, and what you do not use is lost.
What is Bronstein delay?
After each move the clock adds back the time you used, up to the delay. If you move in 3 seconds on a 5-second Bronstein delay you get 3 seconds back; take 8 seconds and you get 5 back.
Which player starts, and which half do I tap?
White starts after you press Start. Tap your own half right after you have made your move; the clock passes to your opponent.
Why does the top clock look upside down?
With “Face-to-face” on, Black’s clock is rotated so the player on the other side of the board can read it. Turn it off if you sit side by side.
Can I give one player more time?
Yes. Type the minutes for Black in the second box; White uses the first.
Does it keep running if I switch tabs?
Yes. Time is measured from the system clock, so the clocks stay correct. Keep the page open and the screen on for long games.