⭐ Starlight Tools / Stopwatch

About this Stopwatch

This free online stopwatch delivers precise timing with zero data collection. It uses the browser’s high-resolution clock (performance.now()) so elapsed time remains accurate and smooth, even if your computer’s system time changes while the timer is running. Everything operates client-side—start, pause, laps, and exports—so your lap data never leaves your device unless you choose to copy or download it.

Core controls are intentionally simple: click Start (or press Space) to begin timing, use Lap (or L) to capture a lap with both the cumulative time and the delta since the previous lap, and press Reset (or R) to clear the session. The lap table shows the lap number, a UTC timestamp, the total elapsed time, and the per-lap delta formatted as hh:mm:ss.mmm. When you’re done, export your results to CSV for spreadsheets or copy a tab-separated version to paste into notes, reports, or project trackers.

Typical use cases include interval training, productivity sprints (e.g., Pomodoro-style sessions without a countdown), classroom or lab timing, user-research tasks, speed-runs, or any workflow where you need quick, trustworthy lap capture. Because this stopwatch avoids network requests and uploads, it’s suitable for privacy-sensitive contexts and low-connectivity environments.

For accessibility and comfort, the display uses tabular numerals to eliminate layout shifts as digits change, and keyboard shortcuts minimize pointer use. If you need calendar math alongside timing, try our related tools below for date differences, time-since/until, and timestamp conversions. Together they form a lightweight, privacy-preserving time toolkit.

Stopwatch: FAQs

How accurate is this stopwatch?

It uses performance.now() for high-resolution timing and is not affected by manual system-clock changes while running.

Do you store or upload my lap data?

No. All operations happen locally in your browser. You decide if you copy or export laps.

What keyboard shortcuts can I use?

Space to Start/Pause, L to Lap, and R to Reset.

Can I export my laps?

Yes. Use Copy Laps for clipboard or Download CSV for a spreadsheet-ready file.

Does it keep timing if the tab is inactive?

Yes. Elapsed time is computed from a monotonic clock when you resume rendering, so pausing the tab doesn’t lose accuracy.