Why does the stopwatch pause in the background?
Browsers slow timers in background tabs to save power, so updates may stop until you return to the tab. Keep the page visible during timed work, or use a dedicated timer app for long sessions.
Online Stopwatch
Start, stop and record laps with a stopwatch that runs in your browser, with split times for each lap.
Runs in your browser — nothing is uploaded
About the Online Stopwatch
A stopwatch is useful for timing workouts, interval sessions, presentations and cooking. Lap times show how each segment compares with the last, which is more informative than the total alone.
Press Start, record laps as you go, and Stop when you finish. The display shows minutes, seconds and hundredths, and each lap shows its total time and the split since the previous lap.
FAQ
Online Stopwatch — frequently asked
How accurate is it?
It uses the browser's high-resolution clock, so the elapsed time is accurate to the nearest hundredth of a second. Your reaction time at the start and end still adds a small error.
Can I resume after stopping?
Yes. Press Resume to carry on from the stopped time. Reset clears the time and all laps.
What is a split time?
A split is the time for one lap, measured from the previous lap. Comparing splits shows whether you slowed down or sped up during a session.
Does it keep my times?
No. Times are kept only while the page is open. Copy any results you want to keep before closing the tab.
Can I use it for a race?
For official timing, use certified equipment. This tool is good for training, practice and casual timing.
Related tools
Swim Pace CalculatorTurn a swim time and distance into pace per 100 metres, pace per 50 metres, speed and pool laps.Heart Rate Zone CalculatorEstimate your maximum heart rate from age and see five training zones in beats per minute, from easy recovery to all-out effort.Crontab CalculatorEnter a five-field cron expression and see the next five times it will run, in your local time zone.