Stopwatch

A stopwatch that measures elapsed time to a hundredth of a second and records lap times. Use it to time running laps, practise a talk or measure how long a task takes.

How to use

1. Press "Start"; the time counts up as hours:minutes:seconds.hundredths.
2. While it runs, press "Lap" to add the time so far as a new row in the table below.
3. Press "Stop" to pause and "Resume" to continue. When stopped, "Reset" returns to zero.
4. Keep the laps with "Copy laps" or "Save as CSV".

How it works

• In the table, "Lap time" is the time since the previous lap, and "Total" is the time from the start to that lap. With two or more laps, the fastest and slowest are marked.
• The start time is saved in this browser on this device, so a running stopwatch keeps going if you reload or close and reopen the tab.
• Shortcuts: Space to start or stop, L for a lap, R to reset when stopped, F for full screen.

Questions and answers

What is the difference between lap time and total time?

Total time runs from the start to the moment you pressed "Lap"; lap time is the difference from the previous lap. With laps at 1:10 and 2:25, the second lap time is 1:15.

Does the stopwatch slow down in a background tab?

No. Only the screen updates pause; the time is calculated from the start time, so the correct elapsed time is shown when you return.

How long can the stopwatch run?

There is no set limit. The hours keep counting past 24.

Can I move the laps into a spreadsheet?

Press "Save as CSV" to download a file with the lap number, lap time and total. You can also press "Copy laps" and paste straight into cells.