Stopwatch

A stopwatch counts up from zero, recording elapsed time — the opposite job to a countdown timer, which counts down to zero. This one keeps accurate time even when the browser tab is in the background, since it timestamps against the system clock rather than relying on a loop that can be throttled by the browser when a tab isn't visible.

Lap times

Recording a lap captures both the split (time since the last lap) and the cumulative total (time since start), shown side by side — the two numbers athletes and coaches actually compare. Useful for interval training, timing repeated tasks, or any activity broken into stages where both the segment time and the running total matter.

Keyboard shortcuts and fullscreen

Space starts and pauses, L records a lap, R resets — fast enough to operate without looking away from whatever's being timed. Fullscreen enlarges the digits for reading from across a room, useful for gym timers, workshops or presentations where the display needs to be visible at a distance.