Stopwatch

Online stopwatch — free, accurate, and private

A stopwatch you can open in any browser, on any device, with nothing to install. Press Start to begin timing, Lap to record split times, Pause to hold, and Reset to clear. The display shows minutes, seconds, and hundredths of a second in a large monospaced readout, so the digits stay steady and easy to read at a glance. Everything runs in your browser — nothing is uploaded, and no account is needed.

It's built for the everyday timing jobs: workouts and intervals, cooking, study or focus sessions, presentations and speeches, lab work, games, or just settling how long something takes.

How to use it

The controls follow the familiar two-button pattern. The right button is Start; once running it becomes Pause. The left button records a Lap while the clock is running, and turns into Reset when the clock is paused, so you can clear everything and start fresh. Pausing keeps your time and laps on screen; pressing Start again resumes from where you left off rather than starting over.

Each lap is added to a scrollable list showing the lap number, the time for that individual lap, and the total elapsed time when you took it. Once you have a few laps, the fastest and slowest are highlighted, which makes it easy to spot your best split in a workout or the slowest step in a process.

Laps and split times

A lap time is the gap between one press of Lap and the next — useful for timing repeated efforts like laps of a track, sets in a workout, or stages of a task. The total, by contrast, is the running time from the very start. Seeing both side by side lets you compare individual efforts while still tracking the overall time. The list keeps the newest lap at the top so the most recent split is always in view without scrolling.

How the timing stays accurate

A naïve stopwatch adds a fixed amount — say ten milliseconds — on every tick. That drifts, because timers never fire at exactly even intervals, and the small errors pile up over minutes. This stopwatch avoids that entirely. It records an absolute timestamp when you press Start and, on every frame, calculates the elapsed time as the real difference between now and that start point (plus any time banked before a pause). The displayed time is therefore always the true elapsed time, not a running tally that can drift.

A helpful side effect is self-correction. If your device slows the page down — which browsers do to save battery when a tab isn't in front — the on-screen numbers may briefly stop updating, but the moment the page gets attention again, the next frame recomputes the elapsed time from the real clock and jumps straight to the correct value. You don't lose time; the display simply catches up.

What to expect on a phone

On a phone, timing is accurate while the browser tab is open and in the foreground. If you switch apps or the screen turns off, the operating system may freeze the page to save power, so the numbers stop moving. When you come back, the stopwatch recalculates from the real elapsed time and shows the correct total — it doesn't fall behind. Still, for anything critical, it's best to keep the tab in front with the screen on. There's no background alarm or notification; this is a stopwatch, not a countdown timer.

Nothing is saved

The stopwatch keeps its state in memory only. That means reloading or closing the page clears the running time and all recorded laps — there's no history to come back to later. If you need to keep your splits, copy them down before you leave. This is a deliberate trade-off for privacy and simplicity: nothing is written to a server or stored on your device.

Privacy: everything stays on your device

The stopwatch runs entirely in your browser. No times or laps are uploaded, nothing is stored on a server, and there is no account to create. It works the same whether you're online or offline, because it never needs to contact a server in the first place.

Frequently asked questions

Is the stopwatch accurate?

Yes. It measures elapsed time from an absolute timestamp rather than adding a fixed amount each tick, so it doesn't drift. Even if the page is briefly throttled, it recomputes from the real clock and corrects itself.

Does it keep running if I switch tabs or lock my phone?

The display may pause when the tab is in the background or the screen is off, because the browser can freeze the page to save power. The elapsed time stays correct and catches up when you return, but for critical timing keep the tab in the foreground with the screen on.

Are my laps saved if I reload?

No. The time and laps live in memory only, so reloading or closing the page clears them. Copy down anything you want to keep before leaving.

Is my data uploaded to a server?

No. Everything runs in your browser — nothing is uploaded, stored, or sent anywhere.