Code tool

Chronometer

Measure elapsed time accurately in your browser with a simple chronometer that keeps its time when you return to the page.

In-browser processingNo account requiredPrivacy details ↗
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Ready to start.

A QUICK WALKTHROUGH

How to use this tool

  1. Select Start to begin measuring elapsed time.
  2. Pause the chronometer whenever you need a reading, then select Start to continue.
  3. Select Reset to clear the elapsed time and return to zero.

High-resolution elapsed time

The display is based on a monotonic high-resolution browser clock when available, so system clock changes do not alter an active measurement. It displays hundredths of a second and continues measuring beyond one hour.

Returning to the page

The elapsed duration is calculated from timestamps rather than animation-frame counts. If the browser pauses background rendering while this tab is hidden, the reading catches up when you return.

Private browser processing

The chronometer runs entirely in this browser. No timing data is uploaded, stored on a server, or sent to a third party.

GOOD TO KNOW

Common questions

Does switching tabs lose elapsed time?

No. When you return, the display is recalculated from the original monotonic timestamp, so time spent in another tab is included while the chronometer is running.

What does pause do?

Pause freezes the accumulated elapsed duration. Starting again continues from that value instead of resetting it.

How precise is the display?

The interface displays hundredths of a second. Actual timing resolution depends on the browser and device, and it is intended for everyday measurements rather than laboratory calibration.