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Stopwatch & Countdown Timer
A stopwatch with laps and a countdown timer with an alarm sound.
Accurate in background tabs: time is measured from the system clock rather than by counting ticks, so it stays exact even if the browser slows the page down. Keyboard: Space start/pause, L lap, R reset.
About the Stopwatch & Countdown Timer
The online Stopwatch and Countdown Timer times anything with lap splits, or counts down to zero and sounds an alarm. It keeps accurate time even when the tab is in the background and works well full screen, so it suits workouts, cooking, exams, presentations, speeches and classroom activities.
How to use the Stopwatch & Countdown Timer
- Choose stopwatch or countdown timer.
- For the stopwatch, press start and record laps as you go.
- For the timer, set the hours, minutes and seconds and press start.
- Pause, reset or go full screen whenever you need.
Frequently asked questions
Does the timer keep running if I switch tabs?
Yes. It tracks time against the system clock, so it stays accurate in a background tab and the alarm still sounds when it reaches zero.
How accurate is the stopwatch?
It measures time to a hundredth of a second using your device’s high-resolution clock.
Can I use it without an internet connection?
Once the page has loaded it runs entirely in your browser, so it keeps working even if your connection drops.