Online Stopwatch
An online stopwatch measures how much time has passed, counting up from zero the moment you press start. This page runs a full-screen stopwatch in the browser with large, readable numbers and lap support, so it works as well on a classroom projector or gym screen as it does on your own laptop. There is nothing to install and no account to create: open the page, press start, and the elapsed time is right there.
When an online stopwatch beats a phone timer
A stopwatch counts up, while a timer counts down to zero. Reach for a stopwatch when you do not know in advance how long something will take and you want to measure it: how fast a student finishes a task, how long a lap takes, how long a machine runs, or how long a discussion actually lasted. A phone stopwatch works for one person, but it is tiny and private. A full-screen online stopwatch turns any shared screen into a timer the whole room can read.
Because it runs in a browser tab, you can put it on a second monitor, a meeting-room display, or a projector without handing your phone around. The numbers scale up to fill the screen, so the elapsed time stays legible from across a gym, classroom, or lab.
Recording laps for training and practice
The lap button records a split without stopping the clock, so you can capture each interval while the overall time keeps running. That is what makes a stopwatch useful for repeated efforts: running intervals, swimming lengths, timed drills, or any activity where you want to compare one round against the next.
A typical flow is simple. Press start when the first effort begins, tap lap at the end of each round, and the running total keeps climbing while each split is logged. When the session is over, press pause to freeze the final time, then reset to clear everything before the next group goes.
Reading the stopwatch across a room
For a shared display, switch to full screen so the browser chrome disappears and only the stopwatch is visible. The large layout is designed to be read at a glance, which matters when an instructor is watching a whole class rather than a single runner. On supported browsers the page keeps the screen awake in full screen, so a long session will not dim or sleep mid-count.
If you need a fixed limit instead of open-ended timing, a countdown timer is the better tool: it counts down from a set duration and signals when time is up. Use the stopwatch when the question is how long did that take, and a timer when the question is how much time is left.
Frequently asked questions
How do I record a lap or split?
Press start, then tap the Lap button at each interval. Each lap is captured without stopping the clock, so the overall elapsed time keeps running while individual splits are recorded.
What is the difference between a stopwatch and a timer?
A stopwatch counts up from zero to measure how long something takes. A timer counts down from a set duration to zero. Use a stopwatch for open-ended timing and a timer for a fixed limit.
Does the stopwatch keep the screen awake?
In full screen the page requests a screen wake lock on supported browsers, so the display stays on during a long session. On unsupported devices, disable sleep in the system settings for extended use.
How precise is the online stopwatch?
The display shows minutes, seconds, and hundredths of a second, and counts hours once the time passes sixty minutes. It is intended for practical training, classroom, and event timing rather than certified race results.
Is the online stopwatch free?
Yes. It runs entirely in the browser with no account or install, and works on laptops, tablets, classroom displays, projectors, and second screens.