Press start and the stopwatch runs in hundredths of a second. Each lap press records a split, the fastest and slowest laps are marked so a set of times is readable at a glance, and the whole table copies out tab-separated for a spreadsheet. Pause and resume as often as you like — no time is lost between segments.
0:00.00
Current lap: 0:00.00
Ready
Time comes from the system clock, so a background tab keeps the total correct even though the display stops refreshing. Nothing is stored — copy your laps before leaving.
How it works
Elapsed time is banked whenever you pause, and the running segment is measured from the clock rather than counted up tick by tick. That means the reading is exact even if the browser slows the page down, and pausing for an hour before resuming adds nothing to the total.
The display refreshes on the browser animation frame while running, which is what makes the hundredths look smooth, and stops entirely when paused so a paused stopwatch uses no processing at all. Because the reading is derived from timestamps, the smoothness of the display never affects accuracy.
A lap press stores the total at that instant. Lap durations are then the differences between consecutive totals, which is why the table shows both: the lap column for the split you just ran and the total column for cumulative time. With more than one lap, the fastest and slowest are marked — unless every lap is identical, in which case marking them would say nothing.
Practical examples
Timing 400 m repeats
Start once and press lap at the end of each repeat. The lap column shows each run, the total column the session, and the fastest lap is marked so you can see whether you faded.
Checking how long a task takes
Start when you begin, pause for interruptions, resume after them. The total counts only the time actually spent, which is the honest number for an estimate.
Logging times into a spreadsheet
Copy laps and paste — the rows arrive tab-separated as lap number, lap time and cumulative time, oldest first, so no reformatting is needed.
Comparing two attempts
Lap after each attempt instead of resetting. Two laps in one list are easier to compare than two numbers you had to write down.
Frequently asked questions
How precise is an online stopwatch?
The reading is derived from the system clock, so it is accurate to a few milliseconds. Your reaction time on the start and stop presses is a much larger source of error than the tool itself — which is true of a handheld stopwatch too.
Does it keep running in a background tab?
Yes. The display stops refreshing when the tab is hidden, but the elapsed time comes from timestamps, so switching back shows the correct total rather than a frozen one.
What is the difference between lap time and total time?
Lap time is the segment since the previous lap press; total time is everything since the start. A set of 60-second laps gives totals of 1:00, 2:00, 3:00 and so on.
Can I pause without losing my laps?
Yes. Pause only stops the clock; recorded laps stay in the table and resume continues the current lap where it left off.
Why are the fastest and slowest laps not marked?
Because there is only one lap, or because all laps are the same length. Marking a single lap as fastest, or every lap at once, would carry no information.
What does the current lap figure show?
Time since the last lap press — the lap in progress. It is the number that matters mid-effort, while the big display gives the total.
Does reset also clear the laps?
Yes, reset clears the clock and the lap table together. Copy the laps first if you want to keep them.
Will my laps survive a page reload?
No, and deliberately so — nothing is stored. Copy the table before closing the tab if the times matter.
Can I use it as a countdown instead?
No, a stopwatch only counts up. For counting down from a set duration use the online timer, which also has an alarm.
Does it work on a phone?
Yes. Keep the screen awake for long sessions, since some phones suspend page timers aggressively when the display sleeps — the total will still be right when you come back, but the live display will not update while asleep.
Is there a keyboard shortcut?
The buttons are reachable with Tab and activate with Space or Enter, which is the fastest way to start and lap without moving the mouse.
Is anything uploaded?
No. The stopwatch runs entirely in the page and no times leave your device.
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