Online Stopwatch
Free online stopwatch with millisecond precision, lap recording, and start beep. Runs entirely in your browser.
Uses high-resolution browser timing. Keeps counting if you switch tabs.
Stopwatch is a precise online stopwatch and lap timer that runs entirely in your browser. ConvertDa's free Stopwatch is millisecond-accurate, supports unlimited laps, and works offline once the page is loaded — perfect for workouts, presentations, cooking, and study sessions.
How to stopwatch
- 1
Click Start to begin.
- 2
Click Lap to record split times while running.
- 3
Click Pause to freeze the time, Reset to clear.
Frequently asked questions
Is it accurate?▾
Yes — uses the browser's high-resolution performance.now() clock with millisecond precision.
Will it keep running if I switch tabs?▾
Yes. The stopwatch keeps counting in the background; the display updates when you return to the tab.
Can I turn off the click sound?▾
Yes — there's a sound toggle button in the controls.
Will the timer keep running if I switch tabs?▾
Yes. The stopwatch continues running in the background. Browser throttling may reduce update frequency for the visible display, but the elapsed time stays accurate.
Can I export my lap times?▾
Click 'Copy laps' to copy the lap list as plain text — paste into a spreadsheet, note, or message.