Stopwatch & Timer

About this tool

Visible timing is useful across a wide range of activities — training intervals, study sessions, cooking, speech practice, and meetings all benefit from a clock you can glance at. This tool puts a stopwatch and a countdown timer on the same page, and the two run independently, so you can time a workout while a rest countdown runs. The stopwatch counts up in whole seconds, shown as mm:ss and switching to hh:mm:ss after an hour. Start, Stop and Start again to pause and resume, press Lap to record the current elapsed time without stopping the clock (newest lap at the top), and Reset to clear the time and laps. The countdown takes minutes and seconds — up to 999 minutes — and counts down to 00:00; pressing Start while it runs pauses it, and Reset reloads your entered time. The countdown shows 00:00 when finished but plays no sound, so keep the page in view.

Why use it

• Stopwatch and Countdown Side by Side: Both timers are on screen at once and run independently, so you can time an activity and a rest period together without opening a second tab.

• Lap Recording: Press Lap at any point to record the current elapsed time without pausing the main clock. Laps appear newest first in a scrollable list.

• Pause and Resume: Both the stopwatch and the countdown can be paused and resumed from the same point, which suits interrupted study or cooking sessions.

• Long Countdowns: The countdown accepts up to 999 minutes plus seconds, enough for long bakes, exams or work blocks.

• Browser-native, No Install: The timers run entirely in browser JavaScript against the system clock. There is no app to download, no account to create, and no permissions to grant.

How to use

1. In the Stopwatch panel, press Start to begin counting up
2. Press Lap to record the current elapsed time, or Stop to pause; Start again resumes
3. Press Reset to clear the stopwatch and its laps
4. In the Countdown panel, set Minutes and Seconds, then press Reset to load the new time
5. Press Start to count down to 00:00; press Start again to pause, and Reset to reload the time

When it helps

• When timing intervals in athletic training such as sprint reps, rest periods, or swimming laps
• When following a Pomodoro or similar timed study technique that alternates focused work with short breaks
• When cooking a recipe that requires multiple items timed simultaneously or in sequence
• When practising a timed presentation, speech, or reading assignment and needing to track pacing
• When running a meeting with an agenda and keeping each topic to a fixed duration
• When conducting a lab experiment, test, or evaluation that requires accurate elapsed-time recording

Examples

Tips

• Lap entries are cumulative — subtract consecutive laps to get each segment's duration
• After changing the countdown minutes or seconds, press Reset so the new time is loaded before you press Start
• The countdown is silent at zero — keep the page visible or pair it with a phone alarm for hands-free use
• Use laps for interval training — reviewing the list afterwards is easier than remembering times
• For regulated competitive timing, use a certified hardware stopwatch — browser timers can lag under heavy CPU load

Frequently Asked Questions

Glossary

Stopwatch

A timing device or mode that measures elapsed time from a start event, counting upward in real time. The user starts, pauses, and resets the timer manually. Precise stopwatches display hundredths or thousandths of a second.

Countdown Timer

A timing mode that counts downward from a preset duration toward zero. When the timer reaches zero, it signals completion — typically with a visual change and an audible alarm.

Lap Time

The duration of a single timed segment between two consecutive lap-trigger events. Lap times measure the pace of individual intervals within a longer session, such as swimming lengths or running circuits.

Split Time

The cumulative elapsed time from the start of a stopwatch session to a specific lap-trigger event. Split times show overall pacing progress and are recorded alongside individual lap times for full analysis.

Elapsed Time

The total time that has passed since the stopwatch was started, including all paused intervals subtracted. It is the value displayed on the main stopwatch face.

Millisecond

One thousandth of a second (0.001 s). Browser stopwatches typically display to the centisecond (0.01 s) level. JavaScript's performance.now() API provides sub-millisecond resolution, though display updates are limited by the screen refresh rate.