Online stopwatch
00:00:00.000
This stopwatch runs entirely in your browser and measures elapsed time from your device clock, so it keeps counting correctly while you switch tabs, lock your phone or leave the page open for hours. When you come back, the reading is exactly where it should be.
Use the buttons on screen, or the space bar to start and pause, L to record a lap, R to reset and F for fullscreen. The stopwatch is the first thing on the page, above any explanatory text.
How to use the stopwatch
Start
Press Start or hit the space bar. The display begins at 00:00:00.000 and counts up in milliseconds.
Pause and resume
Press Pause to freeze the reading at the exact moment. Press Start again to continue from the same point.
Record laps
Press Lap, or the L key, each time you pass a marker. Each lap keeps its own split and the total time next to it.
Reset or go fullscreen
Reset returns the display to zero and clears the lap list. Press F, or the fullscreen button, for a clean full-screen view.
What you get
Millisecond accuracy
Time comes from timestamps taken in your browser, not from a counting interval, so it cannot drift when a tab is throttled or a screen turns off.
Unlimited laps and splits
Record as many laps as you need, while running or paused. Every entry stores its own duration and the running total.
Fullscreen display
One click hides everything else and shows a large reading that stays readable from across a room.
Keyboard control
Space starts and pauses, L records a lap, R resets and F toggles fullscreen, so you never need the mouse mid-session.
Works offline
After your first visit the stopwatch is cached on your device and keeps working without an internet connection.
Light, dark or system theme
The interface follows your system theme, or you can pin it to light or dark. Your choice is remembered locally.
Where people use it
Running and training
Time intervals, sprints and circuit rounds, then read the splits back from the lap list.
Home workouts
Count holds, rest periods and rounds while both hands are busy.
Studying
Measure focused sessions and see honestly where the time goes.
Cooking
Time steps that need a precise reading rather than a rough guess.
Classroom and workshops
Time short activities and put the fullscreen reading on a projector or TV.
Experiments and rehearsal
Measure reaction times, trials and rehearsal runs that need millisecond precision.
Keyboard shortcuts
- SpaceStart or pause
- LRecord a lap
- RReset
- FFullscreen
Shortcuts are ignored while you are typing in a field.
Related tools
- Online stopwatchA free online stopwatch with laps, milliseconds and fullscreen — press Start and time anything in one click.
- Stopwatch with lapsRecord unlimited laps with split and total times — ideal for running, intervals and experiments.
- Full screen stopwatchOne click hides everything else and shows a giant stopwatch readable from across the room.
- TimerPick a preset or type an exact duration and let the timer count down in a display you can read from across the room.
Frequently asked questions
What is a stopwatch?
A stopwatch is a tool that measures elapsed time. It counts up from zero in hours, minutes, seconds and milliseconds, and you can pause, resume, reset and record lap splits.
What is a stopwatch used for?
People use a stopwatch for sports training, running splits, workouts, exams, experiments, cooking, games and any task where you need to know exactly how long something took.
How does a stopwatch work?
This online stopwatch measures time from your device clock using timestamps. When you press Start it stores the start moment; the display is computed from the difference, so it stays accurate even if the tab is in the background.
How do I use a stopwatch?
Press Start to begin timing, Pause to freeze the reading, Lap to record a split without stopping, and Reset to return to zero. You can also use the space bar, L, R and F keys.
How do I start a stopwatch?
Press the Start button on this page. The display begins at 00:00:00.000 and counts up immediately — no sign-up, no download, no settings to configure first.
How do I read a stopwatch?
Read the display left to right as hours, minutes, seconds and milliseconds (HH:MM:SS.mmm). Laps below show each split time next to the running total at that moment.
How do I set a stopwatch?
A stopwatch needs no setting — it always starts from zero. Just open this page and press Start. If you need to count down a fixed duration instead, use the online timer.
How accurate is an online stopwatch?
This stopwatch derives elapsed time from high-resolution timestamps rather than an incrementing counter, so it stays accurate during background tabs, screen locking and long sessions. It is suitable for training, study and everyday timing.
Can I use a stopwatch on my phone?
Yes. This stopwatch works on iPhone, Android and tablets directly in the browser. The controls are touch-friendly and the display scales down to small screens.
Can I use an online stopwatch without downloading an app?
Yes — this stopwatch runs entirely in your browser with nothing to install. After your first visit it is cached and keeps working offline too.