aceclock Open the clock

Online Stopwatch

Start, stop and lap a precise stopwatch right in your browser.

A precise stopwatch that counts up to a hundredth of a second, with lap times and reset. Time a workout, a speech, a science experiment, or anything else — no app to install. Counting down instead? Use the timer.

Guides about Stopwatch

Stopwatch & timer tips How to Time With a Stopwatch and Record Laps A hands-on guide to timing with an online stopwatch and recording laps, covering precision to a hundredth of a second, capturing splits, and reading your results. 5 min read Stopwatch & timer tips Stopwatch vs Timer: Which One Should You Use? A clear comparison of a stopwatch versus a timer, explaining how counting up differs from counting down and exactly which tool fits each task you face. 5 min read

More aceclock pages

Online Clock A big, accurate digital clock showing the current time and date — free, full-screen ready, no download. Analog Clock A clean analog clock with hour, minute and second hands. Countdown Timer Set a countdown timer with an alarm — perfect for cooking, workouts and study.

Frequently asked questions

How precise is it?
It times to a hundredth of a second, which is plenty for workouts, cooking, games and experiments.
Can I record laps?
Yes — tap Lap while running to record split times without stopping the clock.