Online Timer & Stopwatch
Stopwatch, countdown timer, and a live countdown to any date — all in one place
About this tool
This online time tool bundles the three timers you reach for most: a stopwatch that counts up with lap recording, a countdown timer that counts down to zero with a beep, and a date countdown that shows the days, hours, minutes, and seconds remaining until any event. Everything runs locally in your browser using high-resolution timing, so it stays accurate, needs no sign-up, and keeps working even if your connection drops.
How to use
- 1 Pick a mode at the top: Stopwatch, Timer, or Date countdown.
- 2 Stopwatch — press Start to count up, Lap to mark splits, and Reset to clear.
- 3 Timer — type hours, minutes, and seconds (or tap a preset like Pomodoro 25 min) and Start; pause and resume any time.
- 4 Date countdown — choose a target date or an event preset to see the live time remaining; share the page with ?to=YYYY-MM-DDTHH:MM to pre-load a date.
How it works
The stopwatch and timer measure elapsed time with the browser's high-resolution performance clock rather than counting frames, so they stay accurate even if the tab is busy. The timer stores a target instant and on each animation frame computes remaining = target − now, never letting it go below zero; when it reaches zero it fires a short Web Audio beep (audio only plays after you interact with the page, per browser rules). The date countdown takes your target date, subtracts the current time, and breaks the millisecond difference into days, hours, minutes, and seconds. If the date is in the past it simply counts the time elapsed since.
Frequently asked questions
How accurate is the stopwatch?
It uses the browser's performance clock, which is accurate to a fraction of a millisecond, and displays hundredths of a second. Because it stores timestamps rather than counting ticks, it does not drift even if the page is briefly busy.
Will the timer keep running if I switch tabs?
Yes. The remaining time is computed from a fixed target instant, so when you return the display catches up to the correct value. Some browsers throttle background audio, so the beep is most reliable with the tab in front.
Why didn't the timer beep?
Browsers block audio until you interact with the page. Once you have pressed Start or any button, the end-of-timer beep will play normally.
Can I share a countdown to a specific date?
Yes. Add ?to=YYYY-MM-DDTHH:MM to the page URL and it will open with that date pre-loaded — handy for sharing a countdown to a launch, exam, or holiday.
Related tools and uses
For converting between time units see the time and unit converters, and for epoch values try the Unix timestamp converter. The world clock and time-zone tools help when your event spans regions. Use the stopwatch for workouts and lab timing, the timer for cooking and Pomodoro study sessions, and the date countdown for holidays, launches, and deadlines.