Precise Online Stopwatch with Lap Tracking

A free, highly accurate digital stopwatch. Track split times, milliseconds, and continuous laps right in your browser.

Stopwatch

Track laps and total duration accurately.

00:00:00.00

Laps

    No laps recorded.

Online Stopwatch with Lap Timer — Millisecond Precision

The OnlineTimeZone stopwatch delivers 1/100th of a second precision using the browser's native high-resolution timer via requestAnimationFrame. Unlike interval-based timers that drift over time, this stopwatch compares elapsed time against the system clock on every animation frame, ensuring perfect accuracy whether you run it for 10 seconds or 10 hours.

Frequently Asked Questions — Online Stopwatch

How accurate is the online stopwatch?

Extremely accurate. The stopwatch uses requestAnimationFrame and compares elapsed time against the system's high-resolution timestamp (Date.now()) on every frame. This means it does not rely on setInterval counting, which can drift. The result is a stopwatch with no cumulative drift error regardless of how long it runs — making it suitable for athletic timing, lab experiments, and developer benchmarking.

How does the lap function work?

Click the Lap button while the stopwatch is running to record the current elapsed time as a lap. Each lap is saved and displayed in the Laps panel on the right, numbered from most recent at the top. The stopwatch continues running while you record laps — it does not reset between laps. This gives you a continuous total time alongside individual lap splits, just like a professional sports stopwatch.

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

There is no hard limit — you can record as many laps as needed. All laps are stored in your browser session memory and displayed in a scrollable list. Note that laps are cleared when you click Reset or refresh the page, as OnlineTimeZone does not store any data on external servers. Your data stays entirely on your device.

Can I use the stopwatch to measure code execution time?

Yes, developers frequently use the stopwatch to measure rough execution times for processes, builds, or workflows that take several seconds or minutes. For precise microsecond-level benchmarking inside code, use the browser's built-in Performance API (performance.now()), but for timing real-world workflows and processes, this stopwatch is ideal.

Does the stopwatch keep running if I switch browser tabs?

Yes. The stopwatch keeps running in the background even if you switch to another tab, because it records your start timestamp and recalculates elapsed time each frame rather than relying on a counter that could be throttled. When you return to the tab, the display immediately shows the accurate elapsed time with no missed time.

Settings

Customize your OnlineTimeZone experience.

General

Language

Alarm Sound

Generates offline audio

Appearance

Dark Mode

Switch between light and dark themes

Show progress bar

Circular indicator on timers

Behaviors

Loop alarm sound

Plays until dismissed

Show alarm in tab title

Snooze Duration

min

Alarm Volume

50
020406080100

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