Online Stopwatch With Lap Times

Measure elapsed time to the hundredth of a second with this online stopwatch. Start it with a click or a keypress, record as many laps as you need, and compare them at a glance, all in your browser and without installing anything.

How to time something

1. Press start, or tap the Space bar.
2. Each time you finish a lap, segment or repetition, press L or the lap button.
3. Press Space again to pause. Pressing it once more resumes from where you stopped.
4. When you are done, review the lap list, then reset to start a fresh session.

Laps, splits and totals

Every lap is recorded with two numbers: the split, which is the time of that lap alone, and the total, which is the running time since you started. The fastest and slowest laps are highlighted automatically, so you can spot an unusually quick or slow interval without scanning the whole list.

This makes it easy to see whether you are holding a steady pace. A runner doing track repeats, for example, can tell straight away if the last lap was the worst of the session.

Accurate even when the tab is hidden

The stopwatch is timestamp based. Instead of adding up ticks, it compares the current time with the moment you pressed start. That means it stays correct if you switch tabs, minimize the window or your computer gets busy with something else. When you come back, the reading is exactly what it should be.

Good uses for a browser stopwatch

• Running, swimming or cycling intervals with lap-by-lap comparison.
• Timing a speech or presentation rehearsal.
• Science experiments and classroom activities.
• Measuring how long routine tasks really take at work.
• Puzzle solving, speed challenges and board games.

Reading your lap list

Each lap is added to the list as soon as you record it, so you can compare the current interval with the previous one while you are still moving. Looking at the whole list afterwards tells a different story. A steady run shows splits that sit close together, while a big gap between the best and worst highlight usually means you started too fast or faded at the end.

Pausing does not create a lap. If you stop the clock to tie a shoe or set up the next experiment, the paused time is simply left out, and the next lap continues from the moment you resume. Reset clears both the main reading and the list, so note anything you want to keep before you start over.

Practical tips

Keep your hands on the keyboard when precision matters: Space and L react faster than moving a mouse to a button. If several people need to see the time, for example at a training session or a class race, switch to full-screen or projector mode for large digits.

Remember that a stopwatch counts up from zero. If you want to count down from a set duration and hear an alarm at the end, use the online timer instead.