What is a chess clock used for?

It gives each player a separate time budget. Only the player whose turn it is uses time; pressing the clock passes the running timer to the opponent. Put this clock beside your chess board to time a game. It does not supply a playable board or an opponent.

How do I use this chess clock?

Set the base time, mode and seconds before pressing Start. White moves first. After making a move on your board, tap your own clock half or press Pass move. The waiting half does nothing. Pause holds both clocks; Resume continues the same turn. After you engage with the clock, Space passes the move, P pauses or resumes, and U undoes a press.

What is the difference between Fischer increment and delay?

Fischer increment adds the chosen seconds to the player who has just completed a move. Simple delay lets the first part of each turn pass without reducing the remaining time; unused delay is discarded. The Delay mode uses that grace-period display, rather than a Bronstein countdown-and-refund display. Sudden death applies neither increment nor delay.

What do 3+2 and 5+3 mean for blitz?

3+2 gives each player three minutes and adds two seconds after each completed move. 5+3 gives five minutes with a three-second increment. Choose the matching time-control button. For a custom game, enter minutes such as 5 or 2.5, or minutes and seconds such as 1:30. The base can range from one second to 720 minutes, with up to 600 seconds of increment or delay.

Can I use a phone or tablet as a chess clock?

Yes, open the page in a current browser and use the two large clock buttons. Facing turns the Black half around for players sitting across a table. The same controls work in a desktop browser. There is nothing to install, and the timer calculations run locally after the page loads. Load the page before disconnecting; opening it for the first time requires a connection.

What happens when the tab is hidden or the phone locks?

The display may stop updating while the browser suspends the page. When it resumes, the reading includes elapsed device time since the last press. Keep the device clock unchanged during a game. Closing or reloading the page ends the game.

How do I undo a mistaken press?

Undo restores the clocks, move counts and side to move from before the last press, then holds both clocks. Press Resume when ready. You can undo multiple presses, but a fallen flag cannot be undone.

Does a fallen flag decide who wins?

It shows which player ran out of time. This clock has no board position and cannot determine whether the opponent could checkmate, whether a move was legal, or the game result.

Can it time a tournament-style game?

It can time a single-stage control such as 3+2 or 90+30. Choose the matching button or enter the agreed base, mode and seconds. It has no multi-stage controls or board detection. Use at an official event depends on the organizer's equipment requirements; this page makes no tournament-approval claim.

Does it remember my settings?

When browser storage is available, deliberate changes to a valid time control and layout are remembered on this device. Invalid drafts do not replace the last valid control. A game in progress is not saved, so a reload starts with both clocks held.

Chess Clock

Run a two-player clock on one device. Choose a time control, press Start and tap your own half after each move. Pause or undo a mistaken press.

White 5:00 · Black 5:00 · not started · 5 min + 3 s increment

Base time

Mode

Increment (seconds)

Layout

Base time is in minutes: 5, 2.5, or 1:30 for a minute and a half. The seconds field is the increment added after a move is completed, or the delay granted once at the start of a turn.

Common time controls

Ready. Press Start, then pass the move with the big button, a tap on your own half, or the space bar.

The shortcuts wake up once you have clicked or tabbed into the clock, and only while it is on screen. Until then the space bar pages the article down, the way it does everywhere else.

What a move costs

The change to the moving player's clock after one move from a five minute base time.

Increment 3 sa 2 second move1 s added
Delay 3 sa 2 second moveno change
Delay 3 sa 5 second move2 s off the clock
Sudden deatha 5 second move5 s off the clock

Accuracy. Remaining time is calculated from device timestamps, including time while this page is hidden. A changed system clock can affect the reading. Increment is added after a completed move; delay is granted once per turn. This clock does not check moves or decide the result.

Common questions

What is a chess clock used for?: It gives each player a separate time budget. Only the player whose turn it is uses time; pressing the clock passes the running timer to the opponent. Put this clock beside your chess board to time a game. It does not supply a playable board or an opponent.
How do I use this chess clock?: Set the base time, mode and seconds before pressing Start. White moves first. After making a move on your board, tap your own clock half or press Pass move. The waiting half does nothing. Pause holds both clocks; Resume continues the same turn. After you engage with the clock, Space passes the move, P pauses or resumes, and U undoes a press.
What is the difference between Fischer increment and delay?: Fischer increment adds the chosen seconds to the player who has just completed a move. Simple delay lets the first part of each turn pass without reducing the remaining time; unused delay is discarded. The Delay mode uses that grace-period display, rather than a Bronstein countdown-and-refund display. Sudden death applies neither increment nor delay.
What do 3+2 and 5+3 mean for blitz?: 3+2 gives each player three minutes and adds two seconds after each completed move. 5+3 gives five minutes with a three-second increment. Choose the matching time-control button. For a custom game, enter minutes such as 5 or 2.5, or minutes and seconds such as 1:30. The base can range from one second to 720 minutes, with up to 600 seconds of increment or delay.
Can I use a phone or tablet as a chess clock?: Yes, open the page in a current browser and use the two large clock buttons. Facing turns the Black half around for players sitting across a table. The same controls work in a desktop browser. There is nothing to install, and the timer calculations run locally after the page loads. Load the page before disconnecting; opening it for the first time requires a connection.
What happens when the tab is hidden or the phone locks?: The display may stop updating while the browser suspends the page. When it resumes, the reading includes elapsed device time since the last press. Keep the device clock unchanged during a game. Closing or reloading the page ends the game.
How do I undo a mistaken press?: Undo restores the clocks, move counts and side to move from before the last press, then holds both clocks. Press Resume when ready. You can undo multiple presses, but a fallen flag cannot be undone.
Does a fallen flag decide who wins?: It shows which player ran out of time. This clock has no board position and cannot determine whether the opponent could checkmate, whether a move was legal, or the game result.
Can it time a tournament-style game?: It can time a single-stage control such as 3+2 or 90+30. Choose the matching button or enter the agreed base, mode and seconds. It has no multi-stage controls or board detection. Use at an official event depends on the organizer's equipment requirements; this page makes no tournament-approval claim.
Does it remember my settings?: When browser storage is available, deliberate changes to a valid time control and layout are remembered on this device. Invalid drafts do not replace the last valid control. A game in progress is not saved, so a reload starts with both clocks held.

Remaining time is calculated from device timestamps, including time while this page is hidden. A changed system clock can affect the reading. Increment is added after a completed move; delay is granted once per turn. This clock does not check moves or decide the result.