Chess clock offline: play with no signal at all
Club halls have bad signal, school gyms have none, and a clock that needs a connection is not a clock. Load this page once and it keeps working with the network off, because everything it needs is already on your device.
Nothing leaves this tab. The clock is JavaScript running on your own device. No account, no upload, no ads, no time limit — and once the page has loaded it keeps working with the Wi-Fi off.
What this clock does
Nothing is uploaded
The clock makes no network requests at all once the page has loaded. There is no analytics call, no font fetch and no API — your game exists only on your own device.
Your settings stay local
Your theme, your last control and your sound preference are kept in this browser's own storage. Clear your browsing data and they are gone, because there is no account holding a copy.
For a truly cold start, use the app
A browser still needs to have loaded the page at least once. If you want a clock that works from a cold phone in a dead zone, install the free app.
What offline actually means here
Once this page has finished loading, the clock is a self-contained piece of JavaScript. It does not call a server to start a game, to count time, or to decide who flagged. Put the device in aeroplane mode and nothing changes.
Be precise about the limit: the page has to have loaded once. If you close the tab and the venue has no signal, the browser may not be able to fetch it again. For genuinely unreliable venues, the app is the right answer — it lives on the device and opens instantly whatever the network is doing.
Why a clock should not need a connection
Three reasons, all of them practical. Latency is the obvious one: nobody wants a round trip between pressing the clock and the clock stopping. Reliability is the second: a dropped connection mid-game with a server-side clock is a genuine dispute. Privacy is the third, and it is simpler than it sounds — a clock that never sends anything cannot leak anything.
No ads, no tracking, no account
There is no sign-up, no email capture, no cookie banner and no advertising script. That is not a claim about our intentions; it is a property of the page. An ad script would need a network request, and this page makes none once loaded.
It also means the clock cannot slow down because an ad network is having a bad day — which, on a one-minute bullet clock, is not a trivial consideration.
Battery
The clock keeps the screen awake while a game is running and releases the lock the moment a flag falls or you pause. A dark theme on an OLED phone helps; Minimal Dark and Matrix are the two darkest in the list. Over a two-hour classical game, a screen held awake is the main draw on the battery, so plug in for anything long.
Read next
Guides that go with this clock
How to use a chess clock
Who presses first, which hand to use, when to press, and what happens when a flag falls. The whole thing, once, properly.
Read it Getting startedHow to set a chess clock
Digital, analog and app. What to set, in what order, and why every brand hides it behind a different mode number.
Read it Choosing a controlUsing a clock with kids
When to introduce one, which control to start with, and how to handle the first time a child loses on time in a winning position.
Read itFAQ
Questions about this clock
Does this chess clock work offline?
Yes. Once the page has loaded, the clock runs entirely on your own device and makes no network requests at all. Aeroplane mode makes no difference to it. The only requirement is that the page loaded at least once while you had a connection.
Do you collect anything about my games?
No. The clock never sends a request, so there is nothing to collect. Your theme, your last time control and your sound setting are stored in your own browser and never leave it.
Is there an offline app version?
Yes — Chess Timer for iPhone, iPad and Android. It is free to download, lives on the device, and works from a cold start with no signal at all. It plays single-stage controls with Fischer increment.
Free, in your browser
Other clocks on this site
Same engine underneath, set up for a different game. Pick the one that matches what is on the table.
Two players, one phone
Lay the device flat between you. Each player taps their own half, and the far half is rotated so it reads correctly across the board.
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Real multi-stage controls. Reach move 40 and the next period is added to the time you saved, exactly as a hardware clock does.
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