Online Chronometer - Browser Stopwatch with Milliseconds
Measure elapsed time with a local browser stopwatch that supports start, pause, resume and reset.
About this tool
The chronometer uses the monotonic Performance API and displays hours, minutes, seconds and milliseconds. Pausing preserves elapsed time for a later resume.
How to use
- Enter the requested details or choose a supported file.
- Use the local controls to create, inspect or convert the result.
- Review the preview before downloading, printing or copying it.
Features
- Millisecond display.
- Pause and resume controls.
- One-click reset.
Common use cases
- Time a short manual task.
- Measure a development check.
- Track elapsed study or exercise time.
Common issues and tips
- The stopwatch has no lap recording or alarm.
- Background tab throttling and device sleep can affect how often the display refreshes.
Privacy
All data and files are processed locally in your browser and are not uploaded to Tools12345.
Frequently asked questions
Does pause reset the timer?
No.
Are lap times supported?
No.
Does it continue after reloading the page?
No.