Free Online Stopwatch

Online Stopwatch
Precise to the Millisecond

Record lap times, export data, and use keyboard shortcuts. No signup required.

00:00.00

Space: Start/Pause · L: Lap · R: Reset

Features

Millisecond Precision

Accurate timing down to 0.01 seconds

Lap Recording

Record and compare lap times

Data Export

Export lap data as CSV files

Keyboard Shortcuts

Space to start, L for lap, R to reset

How to Use the Online Stopwatch

01

Start Timing

Click the green play button or press the Space key to begin timing. The stopwatch starts counting from zero with millisecond precision. You can also press Space to pause at any time.

02

Record Lap Times

While the stopwatch is running, click the flag button or press the L key to record a lap. Each lap captures the time since the last lap and the total elapsed time. Laps appear in a table below the stopwatch.

03

Reset and Export

Click the red reset button or press R to clear the stopwatch and all lap records. To save your lap data, click "Export CSV" to download a spreadsheet file with all recorded times.

When to Use a Stopwatch

Sports & Fitness Training

Track lap times for running, swimming, or cycling intervals. Monitor rest periods between sets during weight training. Perfect for HIIT workouts and timed exercise circuits.

Cooking & Baking

Time recipe steps precisely—from boiling pasta to baking bread. Record multiple stages of complex recipes with lap times. Never overcook or undercook again.

Scientific Experiments

Measure reaction times, track experiment durations, and record precise intervals for lab work. Export data for analysis and documentation.

Productivity & Time Tracking

Use the Pomodoro technique with precise work and break intervals. Track how long tasks take to improve time estimation and project planning.

Frequently Asked Questions

How accurate is this online stopwatch?

The stopwatch uses the browser's high-resolution timer (requestAnimationFrame) for millisecond-level precision. While not as accurate as a hardware atomic clock, it is more than sufficient for everyday timing needs such as sports, cooking, and productivity.

Will the stopwatch keep running if I switch browser tabs?

Yes. The stopwatch calculates elapsed time based on the system clock, not on animation frames. This means it continues to track time accurately even if you switch to another tab or minimize the browser window.

Can I use keyboard shortcuts on mobile devices?

Keyboard shortcuts (Space, L, R) work on devices with a physical keyboard, such as laptops and desktops. On mobile devices, use the on-screen buttons to control the stopwatch.

How do I export my lap times?

Click the "Export CSV" button above the lap times table. This downloads a CSV file that can be opened in Excel, Google Sheets, or any spreadsheet application. The file includes lap number, lap time, and total time columns.

Is there a limit to how many laps I can record?

There is no fixed limit on the number of laps you can record. However, very large numbers of laps may affect page performance. For most use cases, recording hundreds of laps works smoothly.