Online Stopwatch
Precision millisecond stopwatch with split lap recording and clean fullscreen display.
Recorded Laps
0| Lap # | Lap Delta (Split) | Overall Elapsed |
|---|
How to Use the Online Stopwatch
Click Start (or press Space) to begin timing. Click Pause anytime to freeze the display without losing your elapsed time.
Click Lap (or press L) to log split intervals. The lap table tracks individual split deltas alongside total cumulative time.
Use Copy Laps to export split records to your clipboard, or click Reset (or press R) to clear all values.
Key Stopwatch Features
Calculates elapsed duration directly from authoritative system timestamps, ensuring zero accumulated drift even across background tabs.
Automatically calculates and highlights your best and worst split intervals once two or more laps are recorded.
Enter clean fullscreen mode with high-visibility digits legible from across a gym, classroom, or presentation room.
Runs 100% locally in your web browser with zero tracking cookies, signups, or heavy downloads.
Keyboard Shortcuts
| Key | Action |
|---|---|
| Space | Start / Pause (Resume) stopwatch |
| L | Record new Lap split |
| R | Reset stopwatch and clear laps |
| F | Toggle Fullscreen mode |
| P | Pop-Out Floating Stopwatch (Picture-in-Picture) |
| Esc | Exit fullscreen or close dialogs |
Frequently Asked Questions
How accurate is this online stopwatch?
This stopwatch uses wall-clock timestamps (Date.now()) as its sole source of truth. Even if your browser suspends or throttles background tabs to save battery, the stopwatch calculates exact elapsed time upon return, guaranteeing drift-free accuracy.
What is the difference between Lap Delta and Overall Elapsed time?
Lap Delta is the exact time elapsed since the previous lap (or since starting for Lap 1). Overall Elapsed time represents the total cumulative stopwatch time recorded at the moment the lap button was pressed.
Can I use keyboard shortcuts to control the stopwatch?
Yes. Press Space to Start or Pause, L to record a Lap, R to Reset, and F to enter Fullscreen mode. Press Esc to exit fullscreen or close settings. Shortcuts automatically pause when you type into input fields.
Will the stopwatch continue running if I switch to another tab or minimize the browser?
Yes. Because elapsed time is derived directly from authoritative system timestamps rather than continuous animation frame counts, your stopwatch will display the exact correct elapsed time when you return to the tab.
How do I copy or export recorded laps?
Click the "Copy Laps" button above the lap table to copy a clean, structured text summary of all lap splits, total times, and fastest/slowest highlights directly to your clipboard.