What it does
Useful, focused capabilities
- Monotonic stopwatch timing
- Wall-clock countdown deadline
- Lap and split recording
- Optional sound, vibration, wake lock, and fullscreen
- CSV lap export
Time & productivity · browser-local
Online stopwatch and countdown timer
Use a drift-resistant online stopwatch with laps or a countdown timer with presets, sound, wake lock, fullscreen, vibration, and CSV export.
Work happens in the current browser. The route does not require an account or a server-side processing job.
Interactive browser workspace
Online stopwatch and countdown timer
The live tool is loaded in this browser only. This route does not need camera, microphone, or screen-capture permission for its main task.
Open this local tool →Browser compatibility
Requirements and honest fallbacks
JavaScript; optional Fullscreen, Wake Lock, Vibration, and Web Audio support.
- JavaScript
- Fullscreen API
- Wake Lock API
- Vibration API
- Web Audio
- download support
Questions people ask
Clear answers and limits
Will the countdown drift in a background tab?
It recalculates remaining time from an absolute deadline rather than subtracting interval ticks, limiting ordinary throttling drift.
Is the stopwatch millisecond display hardware accurate?
It uses the browser's monotonic performance clock, but display refresh, input latency, and operating-system scheduling remain outside the page's control.
Does wake lock always work?
No. It requires browser support and permission and may be released when the page is hidden or the device enters a power-saving state.
Can I export countdown history?
This implementation exports stopwatch laps. It intentionally avoids silently storing every countdown.
Why might sound not play?
Browsers can block audio until a user gesture, and muted tabs or system settings can suppress it.