Stopwatch

Lap vs Split Times

A lap time is the elapsed time for that individual segment only (time since the last lap). A split time (shown in the Split column) is the cumulative total time from the very start up to that lap — useful for races where you want to know overall progress at each checkpoint.

Precision

The display updates every 50 ms and shows time to the nearest millisecond. The underlying timer uses performance.now() — a high-resolution timestamp accurate to sub-millisecond precision in modern browsers.

Best & Worst Laps

After recording two or more laps, the fastest lap is highlighted in green and the slowest in red — useful for identifying your best and worst intervals at a glance.

Common Uses for a Stopwatch

• Sports training — time running intervals, swimming laps, cycling sprints. The lap function lets you record each segment without stopping the overall clock.
• Cooking — time pasta, eggs, or any recipe step that needs precise timing.
• Presentations — rehearse talk segments and check you're hitting your time targets.
• Productivity — use the Pomodoro technique (25-minute work sessions) or measure how long tasks actually take.
• Science experiments — record reaction times, pendulum periods, or any timed observation.
• Games — speed-running, escape rooms, quiz timers, or any game that needs a neutral visible clock.

Stopwatch vs Countdown Timer

A stopwatch counts up from zero and measures how long something takes. A countdown timer counts down from a set duration to zero and alerts you when time is up. Use this stopwatch when you want to measure elapsed time or track lap splits. Use the Countdown Timer when you need to be notified when a fixed time period ends — study sessions, cooking, or meeting time limits.