Stopwatch
Precise, private, laps included.
How it works
Under the hood the stopwatch uses performance.now() — a high-resolution monotonic clock — to record when you tap Start and calculate the elapsed time each animation frame. It doesn't drift over long runs. Lap times are stored as timestamps relative to the start, so you can see both each lap's duration and the running total. Everything is in memory — refresh the page and it resets.
How to use
- 01Tap Start to begin.
- 02Tap Lap while running to record a split.
- 03Tap Pause to freeze; Resume to continue.
- 04Tap Reset (visible when paused) to clear.
Frequently asked
How accurate is the stopwatch?open
It ticks on every browser animation frame — typically 60 times a second — using performance.now() which gives sub-millisecond precision. In practice it's accurate to well within 10 ms.
Does it keep time if I switch tabs?open
Yes. We record the start time; the display updates on animation frames but the elapsed time is calculated fresh from the clock each frame.
Can I export lap times?open
Not yet. Copy them from the list manually. CSV export is on the roadmap.