Stopwatch
Press the lap button while running to record splits
How to Use
Start / Stop
Click the center button or press Space to start or pause the stopwatch. Time is preserved when paused.
Record Laps
Record splits while running. See lap times, deltas between laps, and find your fastest and slowest laps highlighted automatically.
Reset
Clear the stopwatch and all recorded laps to start fresh. Press the reset button or press R on your keyboard.
Export Data
Copy your current time or export all laps as formatted text for tracking and analysis in spreadsheets or documents.
Common Uses
- Workouts: Track intervals, rest periods, and total exercise time
- Cooking: Time recipes with precision
- Studying: Use the Pomodoro technique with timed sessions
- Presentations: Practice timing your talks
- Sports: Record lap times for running, swimming, or cycling
Privacy & Limitations
- All calculations run entirely in your browser -- nothing is sent to any server.
- Results are estimates and may vary based on actual conditions.
Related Tools
- Bar Chart Generator -- Create customizable bar charts with horizontal or vertical orientation
- Audio Motion Correlation Visualizer -- Visualize correlation between audio input and device motion in real-time
- Water Heater Cost Calculator -- Calculate annual water heating costs and compare gas vs electric vs tankless
- Split Bill Calculator -- Split a total evenly across a group
Related Tools
View all toolsSquare Footage Calculator
Calculate area in square feet from room dimensions for flooring, painting, and more
Tip Calculator
Calculate tip amount, total, and per-person split
Online Compass
Digital compass using your device's magnetometer sensor
Split Bill Calculator
Split a total evenly across a group
Receipt Total Calculator
Add line items, tax, discounts, tip, and split totals instantly
Shopping List Builder
Build a smart shopping list with quantities, categories, and budget tracking
Stopwatch FAQ
How accurate is this online stopwatch?
This stopwatch measures time to hundredths of a second (10 ms resolution) using your browser's high-resolution timer. While it is accurate enough for most practical uses -- workouts, cooking, studying -- display refresh rate and browser scheduling can introduce 5-15 ms of jitter. For laboratory-grade timing, dedicated hardware is required.
Can I record lap times?
Yes. While the stopwatch is running, press the Lap button (or the L key) to record a split. Each lap shows the split time, the delta from the previous lap, and the cumulative total. The fastest and slowest laps are automatically highlighted in green and red.
What keyboard shortcuts are available?
Space starts and pauses the stopwatch. L records a lap while running. R resets the stopwatch. These shortcuts only work when you are not focused on a text input.
Does the stopwatch work on mobile devices?
Yes. The interface is fully responsive with large touch targets for easy tapping. The circular progress ring and time display scale to fit any screen size.
Can I export my lap times?
Yes. Use the Export Laps button to copy all lap data -- split times, deltas, and totals -- to your clipboard as formatted text. You can paste it into a spreadsheet or document for analysis.
What does the circular ring show?
The progress ring completes one full rotation every 60 seconds. It provides a quick visual reference for the current second within each minute, making it easy to gauge elapsed time at a glance.
What happens if I close the browser tab?
The stopwatch runs in memory and does not persist across page reloads or tab closures. If you navigate away, your current time and laps will be lost. Copy or export your data before leaving the page.
What are good use cases for this stopwatch?
Common uses include timing workouts and rest intervals, cooking and baking, timed study sessions (Pomodoro technique), presentation rehearsal, sports training with lap splits, and any task where you need a quick, accurate timer without installing an app.