Free tool

Online Chess Clock

A two-player tap clock for casual over-the-board games: pick a preset or set a custom time, lay the phone flat between you, and tap your own side after each move. It supports Fischer increment, Bronstein delay, a move counter, optional low-time sounds and fullscreen where the browser allows them. Timing continues from elapsed timestamps once the page has loaded; no account or installation is needed.

On this page

Start the clock
How to use it
Increment vs delay: Fischer and Bronstein
Which time control should you pick?
Clock procedure under the FIDE Laws
Keep learning

Start the clock

The interactive clock needs JavaScript — once this page has loaded it runs entirely on your device. Presets use familiar online labels: 1+0 bullet; 3+2 and 5+0 blitz; 10+0, often called rapid online but classified as blitz by FIDE; and 15+10 rapid. You can also set a custom time with Fischer increment or Bronstein delay.

How to use it

Pick a time control, then place the phone flat between the two players. In portrait the far clock is upside-down on purpose — it faces your opponent. In landscape the clocks sit side by side.
The player with Black starts the clock (tap the Black side) — that starts White’s time, exactly as on a physical clock.
After you move, tap your own side. Your clock stops, your opponent’s starts. While it is not your turn, your button does nothing — it is “locked”, like the real thing.
On a computer, Space or Enter activates a focused clock button. P pauses and R resets while focus is outside a form field. The ⛶ button requests fullscreen where supported.
Under 10 seconds a side’s clock turns red and, when sound is enabled and browser audio is available, gives a warning. At zero the flag falls and both clocks stop.

Increment vs delay: Fischer and Bronstein

A time control like 3+2 has two parts: the base time (3 minutes) and 2 extra seconds per move. The two classic ways of granting those seconds work differently, and this clock supports both.

Fischer increment: the full 2 seconds are added to your clock after every completed move. Move faster than the increment and your time grows, so you can end the game with more time than you started with. This system is widely used online and in FIDE events.

Bronstein delay: your displayed time falls immediately. When you complete the move, the clock returns the time you used, up to the delay amount. A two-second delay therefore returns 1.2 seconds after a 1.2-second move and two seconds after a five-second move. It cannot raise the clock above the time held at the start of the move, and reaching zero before pressing still loses on time.

Simple or US delay is different. It waits for the delay period before the main display begins to fall. The net time used is usually the same, but the display and the moment at which a flag can fall are not. This tool implements Bronstein timing. Increment is widespread online and in FIDE events; simple delay is used in many US tournament settings.

Which time control should you pick?

1+0 · bullet online: An online label for a reflex-heavy game; FIDE places it in blitz
3+2 · blitz: Fast, with an increment that provides time after each completed move
5+0 · blitz: Five minutes per player with no added time
10+0 · online rapid / FIDE blitz: A boundary case: common platform labels and FIDE categories differ
15+10 · rapid: Twenty-five minutes under FIDE’s assumed 60-move calculation

For a learner, 10+0 or 15+10 leaves more room to practise a move-by-move check and calculate short variations than shorter bullet and blitz controls do. The full taxonomy — bullet through classical, and why increment exists — is in chess time controls explained.

Clock procedure under the FIDE Laws

Press with the same hand that moved the piece. The FIDE Laws require it — one hand does both — and it prevents the two-handed “move-and-slam”.
Press after making the move on the board. In the usual clocked case, releasing the piece makes the board move and pressing the clock completes the move. You may not keep a finger on the clock or hover over it, and you remain entitled to press after making your move even if the opponent has already replied.
Touch-move still applies. Touch a piece and you must move it if it has a legal move — pressing the clock does not undo anything. See the touch-move rule.
A flag fall has to be established. Under the FIDE Laws it is deemed to have occurred when the arbiter observes it or either player makes a valid claim. This browser clock stops automatically at zero, but that behaviour does not replace an arbiter’s procedure.
Flagging is not always a win. If your opponent runs out of time but you have no possible sequence of legal moves that checkmates them — say you have only a king — the game is a draw, not a win. See insufficient material.

What is the difference between Fischer increment and Bronstein delay?Fischer adds the full increment after every completed move, so your time can grow above where it started. With Bronstein, the display falls immediately and the clock then refunds the smaller of the elapsed time and the delay. You cannot finish a move with more time than you had when it began. Simple or US delay waits before reducing the main display; that is a separate mode and is not what this clock implements.

Will the screen stay on during a game?In browsers that support the Screen Wake Lock API, the clock asks the screen to stay awake while it is running and releases it when you pause or a flag falls. Timing is computed from timestamps rather than counted in ticks, so even if the tab is briefly hidden the elapsed time stays accurate.

Can we use this for a rated tournament?Use it for casual games or training. In an organised event, use the equipment supplied or approved by the organiser and arbiter. Mobile phones are normally restricted in the playing venue, so do not assume a browser clock is permitted in a rated game.

Why does the other player’s tap do nothing?By design — on a chess clock only the player whose clock is running can press. Your opponent’s side stays locked until you complete your move and tap your own side.

Play online — clocks built in Time controls explained