Online Stopwatch & Timer
A precise stopwatch with laps and a countdown timer with an alarm. Switch to full screen for a big clock.
Shortcuts: Space start/stop · L lap · R reset · F full screen
A stopwatch and timer in one
Use the Stopwatch to measure how long something takes — a run, a speech, a recipe step or a speedrun attempt. Tap Lap to record splits; the fastest lap is marked green and the slowest red. Switch to Timer to count down from any time and hear an alarm when it hits zero.
Popular uses
- Study and work: a 25-minute countdown for the Pomodoro method, or try the dedicated Pomodoro timer.
- Workouts: rest timers between sets and lap times for intervals.
- Classrooms: full-screen countdown for tests and activities.
- Cooking and games: quick 1-, 3- or 5-minute presets.
The clock uses your device’s own time, so it stays accurate when the tab is in the background or the screen is locked. Need more planning tools? See the time-blocking planner, work hours calculator and deadline calculator.
Frequently asked questions
How do I use the online stopwatch?
Press Start (or the Space bar) to begin, Lap (or L) to record a split, Stop to pause and Reset (or R) to clear.
Does the timer keep running in another tab?
Yes. Time is calculated from the system clock, so it stays accurate even when the tab is in the background. The alarm sounds when the countdown ends.
Can I set a custom countdown?
Yes. Type hours, minutes and seconds, or tap a preset such as 1, 5, 10 or 25 minutes, then press Start.
Will the timer make a sound?
Yes. A short beeping alarm plays when the countdown reaches zero. Make sure your device is not muted.
Can I show the clock full screen?
Press the Full screen button (or F) to fill the display — handy for classrooms, workouts and presentations.
How accurate is the stopwatch?
It shows hundredths of a second and uses the high-resolution timer in your browser, so it is accurate to a few milliseconds.