Stopwatch.

A precise browser stopwatch with lap recording. Start, stop, record laps, and reset — no app needed.

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    A simple, precise stopwatch that runs in your browser. Tap Start to begin timing, Stop to pause, Lap to record a split time without stopping, and Reset to clear everything. All lap times are shown below the main display with the total elapsed time for each.

    How to use

    Click Start to begin. While running, click Lap to record a split without stopping, or Stop to pause. Click Start again to resume. Click Reset to clear the display and all laps. Times are shown in hours:minutes:seconds.tenths format.

    A stopwatch is for measuring duration after something starts

    That sounds obvious, but it separates a stopwatch from a countdown or calendar tool. You use a stopwatch when the question is not “how long until?” but “how long has this been going?” or “how long did that take?”

    This tool gives you a simple running measure of elapsed time, plus laps when the total alone is not enough.

    Where it is most useful

    Exercise and training

    Timing sets, rests, intervals, and repeated efforts is easier when the timer is visible and immediate.

    Focus and task tracking

    If you want a realistic sense of how long work actually takes, a stopwatch gives you raw timing without needing a larger productivity system.

    Practice and experiments

    Some activities need both a total duration and split points along the way.

    Why laps matter

    Lap timing is what turns a stopwatch from a basic timer into something more useful for repeated segments. The full duration tells you the whole session length; the laps tell you what happened inside it.

    That matters for workouts, drills, rehearsals, tests, and any activity where comparing sections is part of the point.

    Common mistakes this avoids

    Estimating from memory

    People are consistently bad at judging how long tasks and efforts actually took.

    Losing the overall duration while checking segments

    Without lap support, it is easy to choose between tracking the total and tracking the parts. A stopwatch with laps handles both.

    Using the wrong tool for the job

    If the event has not started yet, you usually need a countdown. If it has started and you are measuring it, you need a stopwatch.

    Practical examples

    Timing a sprint or workout block

    A visible running timer is often all you need to compare repeated efforts honestly.

    Measuring a work session

    If a task “felt like twenty minutes” but actually took forty-five, that is useful information.

    Tracking repeated practice runs

    Laps help when you want to compare sections without resetting the full session.

    What this tool does not do

    This tool measures elapsed time. It does not plan future events, classify sessions automatically, or maintain long-term records by itself. It is best at direct, in-the-moment timing.

    Why it remains useful

    Elapsed time is a basic metric, but it supports better training, better pacing, and better estimation. A stopwatch stays valuable because it answers that question immediately and without extra overhead.

    Examples

    1 km run Start → run → Stop. Shows elapsed time to 0.1 s precision
    Lap recording Lap 1: 1:23.4 · Lap 2: 1:19.7 · Lap 3: 1:21.2
    Cooking timer use Start when food goes in → Stop when done → see elapsed

    FAQ

    How accurate is the stopwatch?

    It displays to 0.1-second precision and is based on performance.now() internally, giving sub-millisecond timing accuracy. Display updates happen every 100 ms.

    Does it work when the tab is in the background?

    The timer keeps running accurately — it uses wall-clock time not frame-based counting. However, the visual display may pause updating until the tab is active again.

    Related tools

    Privacy and data handling

    This tool runs entirely in your browser. Nothing you type or paste is sent to any server — all processing happens locally on your device.