About the Online Stopwatch with Laps
A precise, drift-free browser stopwatch with lap recording, split totals, and fastest/slowest highlighting.
What it is
The Computezy Online Stopwatch is a free browser-based timer that counts up from zero with centisecond precision. Tap Start to begin, Lap to record splits without stopping, and Stop to pause — then Resume to continue exactly where you left off. Reset clears everything for a fresh run.
Everything runs in your browser. No data is stored or sent anywhere — close the tab and all lap records are gone.
Laps vs splits
Lap time
The duration of a single segment — the time since your last lap tap. Useful for comparing individual intervals, rounds, or legs of a race.
Split (cumulative)
The total elapsed time at the moment the lap was recorded. Useful for knowing when each segment finished within the overall session.
Key features
Centisecond display
Shows HH:MM:SS.cc — hours, minutes, seconds, and hundredths — for precise timing at any scale from a second to hours.
Lap table
Each tap of the Lap button records the lap number, individual lap duration, and cumulative split in a scrollable table.
Fastest & slowest
When two or more laps exist, the best lap is highlighted in green and the slowest in red — no counting needed.
Drift-free engine
Uses performance.now() timestamp anchors, not frame counting, so elapsed time stays accurate over long runs and when the tab is throttled.
Screen wake lock
Requests a wake lock on supported browsers while running, preventing the screen from dimming mid-session. Degrades gracefully elsewhere.
Stop & resume
Pause the clock at any moment and pick up exactly where you left off — paused time is excluded from the elapsed total.
Common uses
Workouts & runs
Record lap times for each interval, lap, or set. See at a glance which effort was fastest and which was slowest.
Races & competitions
Time multiple competitors or track splits across legs of a relay — the cumulative split shows finish times without mental arithmetic.
Lab & experiments
Record reaction times, process durations, or trial intervals with centisecond resolution and a clear table to review afterward.
Presentations & speeches
Tap Lap at each section to track how long each part took — useful for rehearsing talks with time targets per segment.
Completely free
No account, no rate limit, no premium tier. Use it as often and as long as you need, on any device, without installing anything.