Online Stopwatch & Timer with Lap Recording, Alerts

Online Stopwatch with Laps and Countdown Timer

This online stopwatch counts up from zero with centisecond precision and unlimited lap recording, so you can time a workout, a study session, or a speedrun and capture every split. No download, no sign-up — open the page and press Start.

It also doubles as a countdown timer: switch to Timer mode, pick a duration, and get a sound alarm, vibration, and a browser notification when time runs out — even if you have moved to another tab. Eight themes and five dial styles let you make it look exactly how you want.

Private by design: every part of the timing runs in your browser. Your lap times never leave your device, no data is uploaded, and once the page has loaded the stopwatch keeps running offline.

How to Use the Stopwatch

Start timing

In the default Stopwatch mode, click Start or press Space (or tap the dial) to begin counting up from zero.

Record laps

While running, click Lap or press L to log a split. Each lap shows its split time, cumulative total, and the delta versus the previous lap.

Or run a countdown

Switch to the Timer tab (or press T while stopped), type hours / minutes / seconds or pick a preset, then start the countdown.

Read your results

The stats footer surfaces your Best Lap, Average Lap, and Total Time live. Press R to reset, or F to go fullscreen.

Keyboard shortcuts: Space start / pause, L lap, R reset, T switch mode (when stopped), F fullscreen. Shortcuts pause automatically while you type in the timer fields.

Features

Stopwatch + Countdown Timer

One tool, two modes: count up from zero with laps, or count down from any duration with alerts.

Lap Recording with Stats

Capture unlimited laps with split, cumulative total, and delta — plus live Best, Average, and Total Time.

Centisecond Precision

Time shows in HH:MM:SS.cs format down to 1/100 of a second, driven by the browser's high-resolution clock.

Countdown Presets & Auto Reset

Quick-start with 1m, 3m, 5m, 10m, 15m, or 30m, set any custom time, and loop the countdown with Auto Reset.

Background-Aware Alerts

A sound alarm, mobile vibration, and an optional browser notification fire when the timer ends — even from another tab.

8 Themes

Choose from Aurora, Ocean, Neon, Retro LCD, Classic, Sakura, Pastel, and Sunset to match your mood or room.

5 Dial Styles

Switch the dial between Ring, Halo, Bar, Flip, and LCD — independently of the colour theme.

Fullscreen Mode

Press F to drop the chrome and fill the screen with the dial — ideal for projectors, kitchens, and the gym.

Screen Wake Lock & Live Tab Title

The screen stays awake while timing, and the tab title updates every second so the clock is visible from any tab.

Auto-Save & Mobile-Ready

Your theme, dial style, mode, and toggles are saved locally, and the responsive layout collapses into a drawer on phones.

Frequently Asked Questions

How do I use this online stopwatch?

Click Start or press Space to begin counting up. Press L or click Lap to record a split, Space again to pause, and R to reset. There is nothing to install — open the page and go.

How do I record a lap or split time?

While the stopwatch is running, click Lap or press L. Each entry lists the cumulative total and a +/- delta against the previous lap. With three or more laps, the fastest is highlighted in green and the slowest in red. Laps apply only to count-up mode, not the countdown timer.

Does the stopwatch show milliseconds?

The display reads HH:MM:SS with two extra digits for centiseconds (1/100 of a second). Timing is driven by the browser's high-resolution clock, which is more than accurate enough for sports, study, cooking, and speedrunning.

Can I run the stopwatch in full screen?

Yes. Click the expand button in the header or press F. The sidebars and tabs hide so the dial fills the screen and the theme paints the whole background — great for class projectors and across-the-room viewing. Press F or Esc to exit.

Will the timer still go off if I switch to another tab?

Yes. The alarm is scheduled with a background-safe timer, so it fires at the right moment even when the tab is inactive. With Browser notification enabled (on by default in Timer mode), you also get a system notification — click it to jump back to the tab.

Does it keep my screen from sleeping?

On supported browsers the screen wake lock activates whenever a stopwatch or timer is running and is re-acquired when you return to the tab. Older browsers ignore the request and the timer still works — just keep the screen on by other means.

What is the maximum time it can track?

Up to 99 hours, 59 minutes, and 59 seconds. The dial loops once per minute in stopwatch mode, while the elapsed total keeps climbing.

Are my settings saved when I close the browser?

Yes. Your theme, dial style, mode, last timer duration, and the sound, auto-reset, and notification toggles are stored in your browser's local storage. Lap entries and the running clock are intentionally session-only, so restored splits never mismatch the timer.

What is the difference between themes and dial styles?

Themes change the colours (palette, surfaces, accents); dial styles change the shape of the progress visual (ring, halo, linear bar, flip cards, or LCD screen). They are independent, so you can mix any of the 8 themes with any of the 5 styles.