Stopwatch
A stopwatch measures elapsed time by counting up from zero. Press start to begin timing, lap to record split times without stopping, and stop to end. Lap time is each individual segment; split time is cumulative from start.
Online stopwatch with lap tracking, best/worst lap highlighting, and keyboard shortcuts. Record split times, export laps as CSV, and copy results. Perfect for workouts, studying, and timing tasks.
00:00:00.00
Keyboard: Space start/stop · L lap · R reset
Tips
- Use Space to quickly start/stop the stopwatch
- Press L to record lap times during workouts
- Best and worst laps are highlighted when you have 2+ laps
- Export laps as CSV or copy as text for your records
- Works offline — no internet needed
How to Use
- Enter your value in the input field
- Click the Calculate/Convert button
- Copy the result to your clipboard
Frequently Asked Questions
- What is the difference between a stopwatch and timer?
- A stopwatch counts up from zero, measuring elapsed time (e.g., running a race). A timer counts down from a set time to zero, alerting when complete (e.g., cooking). Both measure time but serve different purposes.
- How accurate is an online stopwatch?
- Browser-based stopwatches are accurate to approximately 10-15 milliseconds due to JavaScript timing limitations. For casual use, this is sufficient. For professional timing (sports events, scientific experiments), dedicated hardware stopwatches with sub-millisecond accuracy are recommended.
- What is a lap time vs split time?
- Lap time is the duration of one individual lap/segment. Split time is the total cumulative time from start to a checkpoint. If lap 1 takes 30 seconds and lap 2 takes 35 seconds: lap times are 30s and 35s; split times are 30s and 65s (1:05).
- How do I use stopwatch lap function?
- Press the lap button at each checkpoint to record the current time without stopping the stopwatch. This creates a list of split times and calculates lap times. Useful for tracking multiple intervals during exercise, studying, or any timed activity with segments.
- Can I run a stopwatch in the background?
- Our web stopwatch continues running in browser background tabs. However, browsers may throttle inactive tabs, affecting display updates. For long-duration timing, keep the tab visible or use the recorded start time to calculate accurate elapsed time.