Online Stopwatch with Laps and Milliseconds

What is an online stopwatch?

An online stopwatch measures elapsed time in your browser, down to hundredths or thousandths of a second. There is nothing to install: start it with one click on a computer, tablet or phone.

The WebToolsMe online stopwatch does more than count up. As a stopwatch with laps it shows every lap time and the running split, and instantly compares your fastest and slowest laps. You can run up to 10 stopwatches at once and download the results as CSV. Even if you refresh the page or close the browser, the time continues where it left off.

How to use the stopwatch

• Start: press Start or the Space bar and the time begins to run.
• Record a lap: press Lap or the L key at the end of each lap, set or section.
• Stop and resume: Stop freezes the time; Resume continues from the same point.
• Reset: clears a stopped stopwatch; pressed it by mistake? Undo brings it back with all laps.
• Save results: copy the lap table or download it as a CSV file that opens in Excel.

Features

Lap time vs split time

Lap time is the time since the previous lap was recorded, for example how long each 400 m lap of the track took. Split time (total) is the time elapsed since the stopwatch started.

Next to each lap the difference column shows how much faster (green, minus) or slower (red, plus) it was than the lap before. With two or more laps the fastest is highlighted in green and the slowest in red, and the summary above shows your average lap.

Multiple stopwatches at the same time

For coaches, teachers and race organisers there is a multiple stopwatch section below the main stopwatch. Give each one an athlete or task name, start them separately and record laps. Start all starts every stopwatch at exactly the same millisecond, ideal for runners or swimmers who set off together.

What can you time with it?

• Running and athletics: lap times, interval training, 100 m and 400 m.
• Swimming and cycling: laps per pool length or course section.
• Gym and HIIT: track sets and rest periods.
• Studying and exams: time per question and full mock exams.
• Presentations and meetings: speaking time per person.
• Science experiments: reaction and measurement times.
• Cooking, games and puzzles: Rubik's cube solves, recipe steps.

How accurate is the stopwatch?

The stopwatch records the moment it started using your device clock and calculates the difference at every update. So the time does not drift if the tab is in the background, the screen locks or the page reloads. The display refreshes at your screen rate, about 60 times per second.

The real limit is human reaction time: pressing a button usually takes 0.1–0.2 seconds. Official race results use electronic timing; for training, classes and everyday tasks an online stopwatch is more than accurate enough.

Keyboard shortcuts and full screen

• Space: start / stop
• L or Enter: record a lap
• R: reset (while stopped)
• F: full screen, so the time is readable from across a gym, classroom or projector screen

Privacy

The stopwatch runs entirely in your browser. Times, laps and stopwatch names are stored only on this device (localStorage) and never sent to a server. The keep-screen-on option only prevents the screen from sleeping while a stopwatch is running.

Frequently asked questions