Stopwatch
Start, pause, and record laps with hundredth-of-a-second precision. If you switch tabs or reload the page, the time is still correct.
- Space Start or pause
- L Lap
- R Reset
- F Full screen
Laps 0
| # | Lap | Total | Diff. from best |
|---|
The best and worst laps are marked with text, not just color.
Parallel stopwatches
Time several things at once: up to three more stopwatches, each with its own name. Handy for turns, tasks, or sports.
How to use it
- Select Start or press the space bar to begin counting.
- With the stopwatch running, select Lap (or press L) to record a split time without stopping the count.
- Select Pause to stop and Resume to continue. Reset (R) sets everything back to zero.
- Copy the lap table or download it as CSV. To project the stopwatch, use Full screen (F).
Frequently asked questions
Is the stopwatch accurate if I switch tabs or lock my phone?
Yes. The time is not calculated by adding up ticks but by subtracting the start mark from the current moment, so it does not drift even if the browser throttles the page in the background. When you come back you will see the real elapsed time.
What happens if I reload or close the page while the stopwatch is running?
We save the start time and the laps in your browser, not every hundredth of a second. When you open the page again we pick up the count from the real elapsed time. If you clear the site data, it is lost.
How are the best and worst laps marked?
With “Best” and “Worst” labels in the table, plus a soft background. The difference column shows how much slower each lap was than the best one. They are marked starting with the second lap.
Can I time several things at once?
Yes. Below the main stopwatch you can add up to three more, each with its own name and its own buttons, and all of them run in parallel.
Does the screen stay on on my phone?
In browsers that allow it, we ask the screen not to turn off while the stopwatch is running. If your browser does not support it, the stopwatch keeps working, but the screen may turn off depending on your settings.
What keyboard shortcuts does it have?
Space starts or pauses, L records a lap, R resets, and F turns full screen on. They work when the focus is not in a text field.
What a stopwatch with laps is for
A stopwatch measures how long something takes; laps let you split that measurement into segments without stopping the count. With a single screen you can handle very different situations.
Ways to use it
- Running or swimming: record a lap every 400 meters or every pool length and compare the pace of each segment with the others.
- Presentations: mark a lap at the end of each slide or section and find out which one takes longer than planned.
- Cooking and lab work: add up to three parallel stopwatches, each with its own name, to keep track of the dough, the sauce, and the oven at once.
- Study and work: time how long it takes you to solve each practice exercise or to finish a repetitive task.
How to read the lap table
- Lap: the time since the previous lap.
- Total: the accumulated time since the stopwatch started.
- Difference from best: how much slower that lap was than the fastest one. The best and worst are labeled starting with the second lap.
If you need to analyze the data, copy the table with tabs to paste it into a spreadsheet, or download it as CSV.
Why it does not drift
The stopwatch does not add up ticks: it saves the start mark and calculates the time by subtracting it from the current moment. So even if the browser throttles the page in the background or you lock your phone, you see the real time when you come back. If you reload, we pick the count up from what is saved in your browser, and while it runs we ask the screen to stay on, when the browser allows it.
Shortcuts and full screen
Space starts or pauses, L marks a lap, R resets, and F turns on full screen, which is great for projecting the time in a class or at the gym. If you reset by accident, you have a few seconds to select Undo and get the count back.
Time format
It is shown as minutes:seconds.hundredths (for example 01:05.43). Past one hour, the hours appear in front (01:05:43.21). Hundredths are truncated, never rounded up. If what you need is a countdown, use the timer.
Updated on September 30, 2026