What is the difference between a lap time and a split time?

A lap time measures a single, isolated segment of an event—like how long it takes to run one lap around a track. A split time measures the total elapsed time from the very beginning of the timer up to that specific checkpoint.

Can I export or copy my recorded lap times to a spreadsheet?

Yes. Every time you hit the Lap button, we log the data. When you are done, simply click 'Copy All Laps' to grab a cleanly formatted list of your lap and split times. You can paste this directly into Excel, Google Sheets, or a workout journal.

Will the stopwatch stop working if I switch tabs or my screen locks?

No, it will not lose your time. Because our stopwatch calculates elapsed time based on an absolute hardware timestamp, it knows exactly how much time has passed even if you switch browser tabs, minimize the window, or if your screen goes to sleep.

Are there keyboard shortcuts to control the stopwatch?

Yes, to make tracking easier without a mouse, you can use keyboard shortcuts. Press the Spacebar to start or pause the timer, press the 'L' key to record a new lap time, and press the 'R' key to completely reset the stopwatch back to zero.

What is the difference between a lap time and a split time?

A lap time measures a single, isolated segment of an event—like how long it takes to run one lap around a track. A split time measures the total elapsed time from the very beginning of the timer up to that specific checkpoint.

Can I export or copy my recorded lap times to a spreadsheet?

Yes. Every time you hit the Lap button, we log the data. When you are done, simply click 'Copy All Laps' to grab a cleanly formatted list of your lap and split times. You can paste this directly into Excel, Google Sheets, or a workout journal.

Will the stopwatch stop working if I switch tabs or my screen locks?

No, it will not lose your time. Because our stopwatch calculates elapsed time based on an absolute hardware timestamp, it knows exactly how much time has passed even if you switch browser tabs, minimize the window, or if your screen goes to sleep.

Are there keyboard shortcuts to control the stopwatch?

Yes, to make tracking easier without a mouse, you can use keyboard shortcuts. Press the Spacebar to start or pause the timer, press the 'L' key to record a new lap time, and press the 'R' key to completely reset the stopwatch back to zero.

Millisecond Precision Chronometer

High-Precision Online Stopwatch & Lap Timer

Use our highly accurate online stopwatch with lap and split times. Features millisecond precision, exportable data, keyboard shortcuts, and zero time drift.

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Keyboard Shortcuts: Space Start/Pause · L Lap Split · R Reset

Sub-Millisecond Chronometry

An Online Stopwatch You Can Trust for Accuracy

Whether you are timing a 400-meter sprint, tracking intervals for a chemistry experiment, or running a structured study sprint, you need a timer that does not skip a beat. Many basic online stopwatches rely on flawed software loops that quietly lose milliseconds every time your web browser renders a new frame or loads an ad. Over a long session, that can lead to seconds of compounding inaccuracy.

We built this online stopwatch differently. By tapping directly into your device's High-Resolution Time API, our stopwatch bypasses the operating system's standard wall-clock (which can jump around due to background time-syncing) and anchors directly to your CPU's invariant hardware timer. We tie this data directly to your screen's refresh rate, resulting in a laboratory-grade, monotonically increasing timer that delivers perfect sub-millisecond precision with zero drift.

Recording your milestones is effortless. Use the lap functionality to break down complex tasks. The interface clearly separates your isolated 'lap times' (the duration of that specific segment) from your cumulative 'split times' (total time elapsed since you hit start). When you are finished, you can export your entire session history with a single click and paste it perfectly formatted into any spreadsheet or note-taking app. With full keyboard shortcut support and a responsive design, it is the most reliable stopwatch available in your browser.

Lap Times vs. Split Times Explained

Accurate interval measurements, split mathematics, and athletic training applications.

Perfect for Athletics, Laboratories, and Studying

Accurate interval measurements, split mathematics, and athletic training applications.

Keyboard Shortcuts and Easy Data Export

Accurate interval measurements, split mathematics, and athletic training applications.

Frequently Asked Questions About Online Stopwatch

Answers on hardware timing accuracy, lap tracking, background tab persistence, and shortcuts.

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It is incredibly precise. Unlike basic web timers that drift when your computer gets busy, our stopwatch uses your browser's high-resolution performance.now() API. This means it measures time directly from your CPU's hardware clock, guaranteeing sub-millisecond accuracy without any lag.