Online Stopwatch

What it does

A free online stopwatch with millisecond precision and unlimited lap times. Click Start to begin; the elapsed time displays in HH:MM:SS.cc (centiseconds) format. Click Lap to record an intermediate split — useful for timing multiple consecutive activities or workout intervals. Click Reset to clear and start over. Works in background tabs (the timer keeps running even when you switch away).

Common uses: workout timing (HIIT intervals, plank holds, run splits, squat / pushup-set rest); cooking (timing one specific recipe step among many); presentations / meetings (tracking speaking time per agenda item); productivity (timing how long tasks actually take so you can estimate better); kids’ games (timing how fast they can do something); quick scientific / cooking measurements (rough timings where ms precision is enough).

Stopwatch (counts UP from zero, you stop manually) vs countdown timer (counts DOWN from a set duration, alarm fires at zero) — different tools, different use cases. Stopwatch when you don’t know how long something will take and want to measure; timer when you know the duration and want a hands-free reminder.

This page is the same stopwatch as our /stopwatch tool — the duplicated URL captures “online stopwatch” search intent specifically. Both URLs are stable and bookmarkable; pick whichever you prefer typing.

How to use it

1. Click Start. The stopwatch begins counting from 0.00.
2. Click Lap to record a split time. The list builds up showing each lap.
3. Click Stop to pause; Resume continues from the paused time.
4. Click Reset to clear the time and laps. The display returns to 0.00.
5. Lap times are shown both as 'split' (since last lap) and 'total' (since start) — pick whichever measure matters for your use case.

When to use this tool

• Workout intervals, run splits, HIIT timing.
• Cooking when timing a single step matters more than total elapsed time.
• Meeting / presentation pacing.
• Quick measurement of how long any task takes.

When not to use it

• When you need an alarm at a specific duration — use a countdown timer instead.
• Hardware-precision measurements (sub-millisecond, scientific) — browser timer drift is small but real. For lab-grade timing use dedicated equipment.
• Long-running timing across browser sessions — closing the tab loses the timer state. Note the elapsed time before closing.

Common use cases

• Verifying a number or output before passing it on
• Quick use during a typical workday
• Pre-decision sanity-check on inputs and outputs
• Educational use — demonstrating the underlying concept