Online Stopwatch
A precise online stopwatch with lap and split times, millisecond display, keyboard shortcuts and full-screen mode. Copy your laps when you're done. Free, no download.
How it works
- 1
Set the time
Type hours, minutes and seconds, or tap a preset.
- 2
Start
The countdown shows in large digits — go full screen for a classroom or meeting.
- 3
Keep working
It keeps accurate time in a background tab and shows what's left in the tab title.
- 4
Hear the alarm
An alarm sounds when time is up; turn on notifications to see it from other tabs.
Common uses
- Time laps and intervals for running, swimming or training.
- Measure how long tasks take for productivity tracking.
- Run timed experiments or reaction games in class.
About the Online Stopwatch
A precise online stopwatch with lap and split times, millisecond display, keyboard shortcuts and full-screen mode. Copy your laps when you're done. Free, no download.
Elapsed time is calculated from timestamps rather than by adding up ticks, so the stopwatch doesn't drift over long sessions, and pausing and resuming keeps the exact total.
Online Stopwatch is part of a free, privacy-first toolkit. It opens instantly and saves to your browser's own storage, so there's no account to create and nothing is sent to a server.
Because online stopwatch works without any sign-up or installation, you can use it as often as you like and it's always available — on desktop or mobile, and even offline.
Explore more productivity tools, or try Online Timer · Pomodoro Timer.
One-click presets: Online Timer · Pomodoro Timer.
Related tools
Online Stopwatch — FAQ
It measures from your device's clock and displays hundredths of a second. Your reaction time when pressing start and stop is the biggest source of error.