Online stopwatch

Start and pause the online stopwatch

Press Start to measure upward from zero. The online stopwatch shows active elapsed time, including periods between laps and excluding periods when paused. It is useful when you do not know a task’s duration in advance and want to read how much time has passed rather than stop at a chosen countdown deadline.

1. Press Start when the activity begins.
2. Press Lap to record a boundary while timing continues.
3. Pause at the end, then Copy results before clearing your laps.

Resume continues from the paused elapsed time and keeps the existing lap table. Reset returns to zero. If recorded laps exist, the tool asks you to confirm before clearing them. Cancel that confirmation when you still need the results, then copy the table or select its text manually.

The display uses hours, minutes and seconds, with hundredths shown for reading lap values. Seeing hundredths does not establish certified timing accuracy. Device input delay and browser execution affect when actions are recorded. Use appropriate dedicated equipment for official competition timing or any task that requires guaranteed precision.

If you need a finish alarm after a set period, open the 10 minute timer. A stopwatch counts up and does not know when your activity should end. It does not play a completion alarm merely because a particular amount of time has passed.

Space starts or pauses the online stopwatch when focus is outside a field. R requests reset and F requests fullscreen. Normal buttons provide the same actions for touch and keyboard navigation. The state label makes it clear whether the displayed elapsed time is still increasing or being held.

Read lap times and cumulative results

A lap timer records two useful values at every boundary: the time since the previous lap and the cumulative active time since Start. The first lap has the same value in both columns because there was no previous boundary. Later lap durations are differences between cumulative readings.

This is a worked arithmetic example, not recorded race data. The second duration is 23.60 − 10.25 = 13.35 seconds. If you pause for five seconds between the two readings, those five seconds are excluded from active elapsed time. The second cumulative result remains 23.60 when that much active timing has occurred.

Record a lap while timing continues

Press Lap at the end of each segment you want to distinguish. A stopwatch with laps keeps running between those presses, so you can record separate steps without restarting the elapsed display. An optional short label identifies the segment, but you can leave it blank and use the numbered lap name.

For example, time a practice reading, press Lap after each selected section and pause when finished. The table shows the duration of each section as well as the total active period. Choose boundaries before starting when consistent comparison matters; changing the boundary halfway through makes the rows describe different activities.

The online stopwatch accepts up to one hundred laps. When the limit is reached, a message tells you to copy and reset before recording more. It does not silently discard the first rows. Keep labels under sixty characters and avoid private information, especially if you plan to paste results into a shared document.

A lap boundary can include resumed timing after a pause. Suppose Lap 1 is at 10.25 seconds, then you pause, resume and record Lap 2 at 23.60 active seconds. The second lap is still 13.35 seconds. Pause holds elapsed time; it does not reset the previous lap boundary or add a row of its own.

Copy results before resetting

Copy results produces plain text with lap number, label, lap duration and cumulative time. The lap timer reports whether copying succeeded. If browser clipboard access is unavailable, selectable fallback text appears so you can copy it manually. The visible table also remains available for review.

Paste the result into your own notes and check that every row you need is included. The tool does not automatically email, upload or synchronize the table. Reset asks before clearing recorded rows, but once you confirm, the current session’s lap data is removed. Saving settings is not a substitute for keeping your own exported results.

A stopwatch with laps records consecutive boundaries within one elapsed activity. If separate tasks need their own remaining-time displays, use multiple timers. If you already know the duration of each work and rest phase, the interval timer previews that planned sequence instead of measuring it after the fact.

Understand display precision and device limits

The online stopwatch calculates active elapsed time with a monotonic session clock. Pause adds the current run to the accumulated total, and Resume begins another run. Paused intervals are excluded. The displayed values are rounded for readability, while lap arithmetic uses the underlying active-time measurements.

Browser callback frequency is not the stopwatch’s claimed precision. A redraw can be delayed without a separate second being added for every callback. However, device sleep, browser suspension and platform behavior affect what happens during a long interruption. MDN’s performance clock documentation describes the clock and differences around sleep behavior.

Keep the page open for the current elapsed session. Reopening a closed tab is not a reliable way to reconstruct how long an unattended activity ran. The stopwatch provides no background notification or future alarm. For official timing, use equipment designed and approved for the relevant setting rather than relying on this browser display.

The lap timer announces new laps and state changes through a restrained status message, without reading every hundredth aloud. The table has separate headers for lap duration and cumulative time. On narrow screens, scroll the table region to inspect the columns while keeping the controls readable and reachable.

Fullscreen gives the elapsed digits more room. Escape exits supported fullscreen, and a rejected request leaves the ordinary page usable. Keep screen awake is an optional browser request while running. It can be denied or released by the device; the visible status tells you whether it is currently active rather than guaranteeing that the device cannot sleep.

Task and lap labels are text. They are displayed as text and are not inserted as executable markup or public URL state. Optional local saving can retain a paused snapshot and recorded laps in this browser. A saved running snapshot requires deliberate review and restores as paused; it cannot certify elapsed time while the page was closed. Clear saved settings on a shared device.

If Copy results fails, use the fallback text before resetting. If a lap looks unexpected, compare its cumulative reading with the previous row and check whether the boundary was pressed at the intended moment. For a reproducible issue, send the page URL, browser and action sequence through Contact, omitting private labels and any sensitive pasted results.