Online Stopwatch with Laps
Measure elapsed time with precision and track laps.
Elapsed Time
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How to use the online stopwatch
This browser-based stopwatch measures elapsed time down to the centisecond (hundredth of a second). Press Start to begin timing. Press Lap to record a split time without stopping the clock — useful for tracking intervals during runs, workouts, experiments, or any activity where you need multiple checkpoints. Press Pause to freeze the display, and Reset to clear everything and start over.
What are laps and split times?
A lap (also called a split time) records the time elapsed since the last lap — not since the start. This is different from the total time, which shows how long the stopwatch has been running overall. For example, if you're running 400-meter laps and your first lap is 1:30 and your second lap is 1:25, the total time after two laps is 2:55. The lap table shows both the individual lap duration and the cumulative total, so you can track your pace at a glance.
Common uses for a stopwatch
- Running and athletics: Track mile or kilometer splits to monitor pace consistency during training.
- Science experiments: Time chemical reactions, physical processes, or biological observations with centisecond precision.
- Cooking and baking: Time individual steps in a recipe that requires precise timing.
- Productivity sprints: Use the Pomodoro Technique by timing 25-minute focused work intervals.
- Speed cubing and puzzles: Measure solve times for Rubik's cubes, jigsaw puzzles, or other timed challenges.
- Classroom activities: Teachers use stopwatches for timed quizzes, presentations, and science labs.
Stopwatch vs. countdown timer
A stopwatch counts up from zero — it measures how much time has passed. A countdown timer counts down from a set duration — it tells you how much time remains. Use a stopwatch when you don't know how long something will take and want to measure it. Use a timer when you have a fixed duration (like 10 minutes for boiling eggs or 25 minutes for a Pomodoro session). Both tools are available on this site — try the Countdown Timer for duration-based timing.
Technical details
This stopwatch uses Date.now() for timing, which provides millisecond-level accuracy. The display updates every 10 milliseconds (centisecond precision). The timer runs entirely in your browser — no data is sent to any server, and the stopwatch works even if your internet connection drops after the page has loaded. Note that modern browsers may throttle JavaScript timers in background tabs, so keep the tab visible for the most accurate results.
Related tools
- Countdown Timer — set a timer for a specific duration.
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- Meeting Planner — find overlapping hours across timezones.
- World Clock — see the current time in 60+ cities.
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Frequently Asked Questions
An Online Stopwatch is a digital timekeeping tool that measures elapsed time with high precision. Our version includes start, pause, reset, and lap functionalities, making it perfect for a wide range of timing needs.
Click the 'Start' button to begin timing. The button will then change to a 'Pause' button, which you can click to halt the timer. Click 'Start' again to resume from where you left off.
The 'Lap' button allows you to record a specific split time without interrupting the main timer. When you click 'Lap', the time for that segment is recorded in the table below, and the timer for the next lap begins immediately.
Click the 'Reset' button to stop the timer completely, clear the displayed time back to zero, and erase all recorded laps. You can only reset the stopwatch when it is paused or stopped.
This stopwatch measures time down to the centisecond (one-hundredth of a second), providing a high level of precision suitable for sports, scientific experiments, and other activities.
'Lap' is the lap number. 'Lap Time' is the duration of that specific lap only. 'Total Time' is the cumulative time from the very beginning of the session up to the end of that lap.
You need an internet connection to load the webpage. However, once loaded, the stopwatch runs entirely within your browser and does not require a continuous internet connection to function.
Modern browsers may slow down or pause JavaScript timers in background tabs to save resources. For the most accurate timing, it is best to keep the stopwatch tab visible and active.
Currently, there is no direct export feature. However, you can easily copy and paste the lap data from the table into a spreadsheet or text document for your records.
There is no set limit to the number of laps you can record. The lap table is scrollable, allowing you to record as many split times as you need for your activity.
A stopwatch measures time that has passed, counting up from zero (elapsed time). A countdown timer counts down from a specified duration to zero.
Absolutely. The lap feature is ideal for runners who want to track their time for each mile, kilometer, or lap around a track without having to stop and reset the timer.
No, this stopwatch is a silent tool. It does not make any beeps or alarms when you start, stop, or record laps.
If you close the tab, the current stopwatch session, including the elapsed time and all lap data, will be lost. The timer does not persist between sessions.
This is a web-based tool, but it is fully responsive and designed to work perfectly on mobile phone and tablet browsers.
This is correct. The first lap's duration is, by definition, the same as the total elapsed time at the moment you press the 'Lap' button for the first time.
This stopwatch is designed to time a single event with multiple splits (laps). To time several separate events simultaneously, you would need to open the stopwatch in multiple browser tabs.
The stopwatch's timing is based on your device's internal clock. While generally very accurate for measuring durations, it is not synchronized with an external atomic clock.
The time is displayed as MM:SS.CS, which stands for Minutes, Seconds, and Centiseconds. The large digits are minutes and seconds, and the smaller digits are hundredths of a second.
No, the 'Lap' button is disabled when the stopwatch is paused. Laps can only be recorded while the timer is actively running to ensure accurate split times.