Stopwatch
A large, readable stopwatch for classroom activities, with named lap times and a fullscreen mode the whole room can see. Use it to time an experiment, a reading race, a group task or a fitness circuit, and keep a record of each round without writing anything down.
Recorded Laps
How to use the stopwatch
Start timing
Press Start, or tap Space. The display counts up in minutes, seconds and hundredths.
Record laps
Press Lap, or tap L, each time a round finishes. Type a name in the box first — a student's name, a station, a group — and the lap is recorded under that name instead of a number.
Watch the split
Once a lap is recorded, the split time shows how long the current round has been running, separately from the total, so you can see whether a group is speeding up or slowing down.
Show the room
Press F or the fullscreen button. The digits fill the screen so the timer is readable from the back of the class.
Keep the results
Press Export to download all lap times as a text file, with names and durations, for your records or to hand back to students.
Frequently asked questions
- Can I name the laps?
- Yes. Type a name into the box before pressing Lap and the lap is stored under that name. It makes the export readable when you are timing several students or stations.
- Does pausing lose my time?
- No. Pause holds the clock exactly where it is, and pressing Start again carries on from that point rather than restarting.
- Are my lap times still there tomorrow?
- Yes. Laps are saved in your browser, so they survive closing the tab. Pressing Clear removes them for good, and that stays cleared after a reload.
- Can I hide the hundredths?
- Yes. Turn off Show Milliseconds in Settings for a calmer display when the exact hundredth does not matter. The preference is remembered.
ClassBox is free and has no ads, no accounts and no trackers. The stopwatch runs entirely in your browser — whatever you type stays on your device.