Stopwatch with laps
Built for intervals: every press of L stamps a lap, and the table keeps splits, totals and your best round side by side.
Guide
How to use it
- Start with the button or the space bar.
- Press L at the end of every interval, work bout, rep or lap of the track.
- Read the Split column for each interval’s own time and vs best for how far off your fastest it was.
- Stop with space when the set ends, the table stays put for reading and copying.
- R resets everything for the next set.
Examples
Session patterns
Track intervals: lap at every finish line. Consistent splits matter more than one heroic opener, the vs-best column makes the fade obvious.
Thirty seconds hard, thirty easy. Lap on every change and the alternating splits should read like a metronome, when the hard 30s drift up, the set is done.
Lap at the end of each round of a five-exercise circuit. Round three is usually the honest one, pace off that next week.
Method
How it works
Each lap stores the elapsed total at the moment you press, splits are computed as the difference between consecutive laps, so a missed press simply merges two intervals rather than corrupting the set.
The clock is the browser’s monotonic timer, unaffected by tab switching or the system clock, and the green highlight tracks your fastest split as the set grows.
FAQ
Frequently asked questions
What happens if I miss a lap press?
Nothing breaks, that split just covers two intervals. Press L on the next boundary and carry on, the totals stay correct throughout.
Can I lap while the page is in the background?
The keyboard shortcuts need the tab focused. For hands-busy sessions put the tab full screen on a phone within reach.
How many laps can it hold?
Hundreds. Long sets scroll within the table rather than pushing the page about.
Is my best lap saved between sessions?
No, a reset clears the set. Copy the table into a note or spreadsheet if you track progress week to week.
Why do my splits differ from my sports watch?
Reaction time at the button, usually a tenth or two per lap. For comparing intervals within one session it cancels out.
Can I time multiple people?
One clock per tab. Open a second tab for a second athlete, each keeps its own laps.
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