Stopwatch & Timer

A precise online stopwatch and countdown timer in one

Sometimes you just need to time something right now without hunting for an app or a physical stopwatch, and this tool is ready the moment the page loads. It combines two essentials in one place: a high-precision stopwatch that counts up with lap tracking, and a countdown timer that counts down to zero and alerts you with sound. Both are accurate because they measure against the real system clock rather than counting frames, so your times stay trustworthy even on a busy machine.

The stopwatch is built for repeated intervals. Start it with one click and it displays elapsed time down to hundredths of a second; tap Lap while it runs to record split markers without interrupting the count, and each lap shows both the time since the previous marker and the running total. That makes it ideal for timing sprints, sets at the gym, cooking stages, or any activity where you want to compare one round to the next.

The countdown timer flips the same precision into a focused deadline. Set hours, minutes, and seconds, press start, and watch it tick down; when it reaches zero it plays a clear beep generated with the Web Audio API and flashes a finished message so you never miss the moment. You can pause and resume either mode without losing your place, and because everything is client-side, the tool works instantly, privately, and offline.

Why use Stopwatch & Timer?

Two tools in one

Switch between a count-up stopwatch and a count-down timer from a single tabbed interface.

Lap tracking

Record split times on the fly, each showing both the interval and the cumulative total.

Audio alert

The countdown plays a clear Web Audio beep and flashes on screen when time runs out.

Accurate and instant

Timestamp-based timing stays precise, and the tool loads and runs entirely in your browser.

How to use Stopwatch & Timer

1
Pick a mode
Choose the Stopwatch tab to count up or the Timer tab to count down.
2
Start timing
Press start; the stopwatch counts up, or set hours, minutes, and seconds first for the timer.
3
Record or wait
Tap Lap to mark splits on the stopwatch, or let the timer run down to zero.
4
React to the result
Review your laps, or respond to the audio alert and finished message when the timer ends.

Common use cases

Workouts and intervals

Time sprints, circuits, and rest periods, using laps to compare each round of a set.

Cooking and baking

Set a countdown so you never overcook a dish, with an audible alert from another room.

Study and work sprints

Give yourself a fixed block of focused time and stop cleanly when the timer sounds.

Games and presentations

Keep speeches, debates, or board-game turns fair with a visible, precise countdown.

Features at a glance

Stopwatch accurate to hundredths of a second
Unlimited lap recording with split and total
Hours, minutes, and seconds countdown input
Web Audio beep alert on completion
On-screen finished indicator
Pause and resume for both modes
Test-sound button to check volume
Fast, private, offline-capable operation

Frequently asked questions

How accurate is the stopwatch?

The stopwatch measures elapsed time against the system clock and refreshes on every animation frame, displaying results down to hundredths of a second. Because it tracks real timestamps rather than counting frames, it stays accurate even if the tab briefly drops frames.

How do lap times work?

While the stopwatch runs, pressing Lap records a marker without stopping the clock. Each lap shows both the split time since the previous lap and the total elapsed time, which is ideal for timing repeated intervals like sprints or work rounds.

Will the timer alert me when it finishes?

Yes. When the countdown reaches zero it plays a short beep sequence generated with the Web Audio API and flashes an on-screen message. You can preview the sound at any time with the Test sound button to make sure your device volume is up.

Can I pause and resume?

Both the stopwatch and the countdown timer support pausing and resuming. The stopwatch keeps its accumulated time, and the timer keeps its remaining time, so you can step away and continue exactly where you left off.

Does it work if I switch tabs?

The timer and stopwatch rely on real timestamps, so the total elapsed and remaining time remain correct even if you switch tabs. Note that the audio alert plays when the timer finishes, though some browsers throttle background tabs, so keeping the tab visible is most reliable.

Your privacy matters

Stopwatch & Timer runs entirely in your web browser. Your files, text, and data are never uploaded to any server, never stored, and never seen by us or any third party. This client-side architecture means you can safely process confidential business documents, personal records, and proprietary data without privacy concerns.