Is this a free online stopwatch?

Yes. This online stopwatch runs in the browser with a large display, lap timing, adjustable precision, and wake lock—no app download or account.

Can I use this online stopwatch for study?

Yes. Start when a study block begins and stop when you pause. For a fixed countdown such as 25 minutes, use the Classroom Timer instead.

Does the online stopwatch support laps?

Yes. Record laps while running, show split and/or total columns, and see the fastest and slowest segments highlighted.

How precise is the display?

Hundredths of a second are shown by default. Settings can switch to tenths or milliseconds; timing itself always uses timestamp differences.

Can I project the online stopwatch on a classroom screen?

Yes. Expand the display to enlarge the digits for projectors and classroom boards. Use wake lock when supported so the display is less likely to sleep.

Does a refresh preserve my laps?

No. The current version starts with a clean session after a page refresh. Copy results before closing if you need to keep them.

Are there keyboard shortcuts?

Yes. When focus is not on a control: Space starts or stops, L records a lap, and R resets.

How is this online stopwatch different from Google’s stopwatch?

This online stopwatch is built for classroom and study use: a larger shared display, configurable lap columns, precision settings, shortcuts, and wake lock—without leaving ClassroomTimers.

00:00.00

Select Start to begin. Record laps while the stopwatch is running.

Online stopwatch for study, classroom drills, and training

This free online stopwatch starts in the browser with a large, easy-to-read display. Time study sessions, classroom drills, and practice runs; record laps while running; choose centisecond or millisecond precision; and expand the display so the whole room can follow the elapsed time—no download or account required.

Project the stopwatch for the whole room

Expand the display to hide navigation and enlarge the elapsed time for projectors, classroom boards, and spare monitors—digits students can read from a distance.
When supported, wake lock helps the display stay visible during long drills instead of dimming mid-session.
Start, Stop, Lap, and Reset stay large enough for quick classroom use on phone, tablet, or desktop.

Centisecond and millisecond precision

Defaults to hundredths of a second (0.01)—centisecond timing that stays easy to read during drills.
In Settings, switch the display to tenths (0.1) or thousandths (0.001) without changing the underlying timestamp-based timing.
For official competition results, use certified timing equipment; this free online stopwatch is built for classroom practice, study, and everyday measurement.

Online stopwatch with lap timing

Select Lap while running to record a split without stopping—ideal for laps, stations, or task segments.
Choose lap columns: split only, total only, or both split and cumulative time.
The fastest and slowest recorded segments are highlighted so you can spot outliers after a drill.

Accurate even in a background tab

Elapsed time is calculated from timestamps, not accumulated animation frames, so background-tab throttling does not make timing run slow.
Stop and Resume keep previous laps; Reset clears the session when you are ready for a new run.
A page refresh starts a clean session—copy results before closing if you need to keep them.

Use Cases

Use the online stopwatch for study blocks: start when focus begins, stop when you break, and review how long each subject actually took.
Time classroom drills, reading races, lab steps, or speaking turns with a shared online stopwatch on the board.
Record lap times for PE circuits and practice runs; compare split and total times after each set.
Track work segments—start a task, Lap when you switch, and finish with a clear total for each block.
Rehearse presentations or demos and note how long each section runs before the live session.
Need a countdown for a fixed study interval (5, 10, 25 minutes)? Use the Classroom Timer. Need the current time only? Open Digital Clock or Flip Clock.

How to use the online stopwatch

Select Start to begin; large digits show elapsed time immediately.
Select Lap while running to record a split without stopping.
Stop and Resume without losing previous laps; Reset clears time and laps.
Open Settings to change display precision, lap columns, and optional sound feedback.
Expand the display when the room needs a shared view; enable wake lock for long sessions.
When focus is not on a control: Space starts or stops, L records a lap, and R resets.

Online stopwatch vs countdown timer

A stopwatch measures how long something took—elapsed time counting up from zero, with optional laps.
A countdown constrains how long something may take—time counting down to zero with a finish cue.
Choose this online stopwatch for measurement and laps. Choose the Classroom Timer when you need a fixed-length study or lesson countdown.

Related classroom tools

Online Stopwatch FAQ

Is this a free online stopwatch?: Yes. This online stopwatch runs in the browser with a large display, lap timing, adjustable precision, and wake lock—no app download or account.
Can I use this online stopwatch for study?: Yes. Start when a study block begins and stop when you pause. For a fixed countdown such as 25 minutes, use the Classroom Timer instead.
Does the online stopwatch support laps?: Yes. Record laps while running, show split and/or total columns, and see the fastest and slowest segments highlighted.
How precise is the display?: Hundredths of a second are shown by default. Settings can switch to tenths or milliseconds; timing itself always uses timestamp differences.
Can I project the online stopwatch on a classroom screen?: Yes. Expand the display to enlarge the digits for projectors and classroom boards. Use wake lock when supported so the display is less likely to sleep.
Does a refresh preserve my laps?: No. The current version starts with a clean session after a page refresh. Copy results before closing if you need to keep them.
Are there keyboard shortcuts?: Yes. When focus is not on a control: Space starts or stops, L records a lap, and R resets.
How is this online stopwatch different from Google’s stopwatch?: This online stopwatch is built for classroom and study use: a larger shared display, configurable lap columns, precision settings, shortcuts, and wake lock—without leaving ClassroomTimers.