Stopwatch & Timer
A precise online stopwatch with lap times and a countdown timer with an alarm — free, private and right in your browser.
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Quick answer
Switch to the Stopwatchtab and press Start to count up — use Lap to record splits. Switch to the Countdown Timertab, set hours, minutes and seconds, then press Start; when it hits zero the tool beeps and flashes “Time’s up!”. Nothing is uploaded — it all runs on your device.
A stopwatch and a countdown timer in one
This free tool combines the two things people time most often. The stopwatch counts upward from zero and is perfect for workouts, cooking, experiments, presentations or any activity where you want to know exactly how long something took. The countdown timercounts down from a time you choose and rings an alarm at zero — ideal for study sessions, HIIT intervals, steeping tea, or keeping meetings on track.
How the timing stays accurate
The stopwatch reads your browser’s high-resolution monotonic clock rather than the wall clock, so it can't drift when the system time changes and it resolves down to hundredths of a second. The countdown timer stores a fixed finish time and works out the remaining time from that on every frame. Because the maths is anchored to a single target, the timer self-corrects — even if a background tab is throttled, it shows the right time the moment you switch back.
Lap times, splits and the alarm
On the stopwatch, pressing Lapstores the moment without stopping the clock. Each row lists the split for that lap and the running total, and the quickest and slowest laps are marked so you can spot your best effort at a glance. On the countdown timer, the alarm is a short beep generated with the Web Audio API together with a visual flash, so you’ll notice the end of the timer whether or not your sound is on.
Frequently asked questions
Is this online stopwatch accurate?+
Yes. The stopwatch is driven by your browser's high-resolution performance clock and updates on every animation frame, so it stays accurate to a hundredth of a second even if the page redraws.
Will the countdown timer make a sound when it ends?+
Yes. When the countdown reaches zero it plays a short beep using the Web Audio API and flashes a clear “Time’s up!” message. Make sure your device isn’t muted to hear the alarm.
Does the timer keep running if I switch tabs?+
The countdown is based on a fixed end time, so even if the browser slows the page in a background tab, the remaining time is recalculated from the clock and stays correct when you return.
Can I record lap times on the stopwatch?+
Yes. Press Lap while the stopwatch runs to record a split. Each lap shows both the individual lap time and the total elapsed time, and the fastest and slowest laps are highlighted.
Do I need to install anything or sign up?+
No. Everything runs in your browser with no sign-up, no download and no data sent anywhere. Open the page and start timing straight away.