Accurate stopwatch with lap times and millisecond precision.
This free online stopwatch delivers millisecond-precision timing directly in your browser. Whether you're tracking workout intervals, timing a presentation, measuring task durations, or running a race, this tool gives you the accuracy and features you need without any app download or installation.
An online stopwatch is a browser-based timing tool that measures elapsed time from a starting point. Unlike physical stopwatches, an online version is always available on any device with a browser — your phone, tablet, laptop, or desktop. It starts, stops, and resets with a single click, and this version also supports lap recording for split-time tracking.
This stopwatch uses JavaScript's high-resolution timing API to deliver accuracy down to the millisecond. The display updates every 10 milliseconds, giving you a smooth, real-time readout in hours, minutes, seconds, and milliseconds format (HH:MM:SS.mmm).
Lap times are recorded with both the individual lap duration and the cumulative total time, making it easy to compare performance across intervals. All lap data is displayed in a scrollable table so you can review your splits at a glance.
The stopwatch is designed to be as simple as possible to operate, even under pressure:
Keep the stopwatch tab visible and avoid switching away from it during critical timing sessions. While the timer continues running in the background, having it visible ensures you don't miss a lap or forget to stop it at the right moment.
Use the lap feature strategically. For interval training, record a lap at the end of each work period and each rest period. This gives you a complete picture of your performance over time and makes it easy to spot trends or improvements across sessions.
For presentations and speeches, do a full practice run with the stopwatch before the real event. Record laps at the end of each major section to see how your time is distributed. This helps you identify sections that run too long and need trimming.
Most phone stopwatch apps are buried in the clock app and require unlocking your device. This browser-based stopwatch is always one tab away, works on any screen size, and doesn't require you to pick up your phone. It's ideal for use on a laptop or desktop during work or study sessions.
The clean, distraction-free interface keeps the focus on the timer. There are no pop-ups, no notifications, and no unnecessary features cluttering the screen. Just a large, readable display and the controls you need.
Your privacy is our priority. All processing happens entirely in your browser using JavaScript. No files, data, or inputs are ever uploaded to any server. Everything stays on your device, making this tool completely safe to use with sensitive content.
Yes. Press the Lap button while the stopwatch is running to record a split time. Each lap is listed below the main timer showing both the lap time and the cumulative elapsed time. You can record as many laps as needed.
The stopwatch uses JavaScript's performance.now() API which provides millisecond precision. However, browser timers can drift slightly over long periods due to tab throttling (browsers slow down timers in background tabs). For critical timing, keep the tab active and in focus.
Modern browsers throttle JavaScript timers in background tabs to save battery. The stopwatch may run slightly slower when the tab is not active. For accurate timing, keep the stopwatch tab in the foreground.
You can copy the lap times from the display. For a formatted export, select all the lap data and paste it into a spreadsheet or text editor. The data is available as long as the page is open.
A stopwatch counts up from zero, measuring elapsed time. A countdown timer counts down from a set duration to zero. Use a stopwatch to measure how long something takes; use a countdown timer to limit how long you spend on something.