About onlineclock.app

onlineclock.app is a set of free, fast clocks, timers and time converters that work in any browser.

It started with a simple problem: the clock in the Windows taskbar is too small to read from across a desk. So the home page is one big, clear clock, and everything else grew from there: stopwatch, timer, alarm, world clock, converters and calculators.

How it works

Every tool runs entirely in your browser. The time comes from your own device, which keeps itself in sync with internet time servers. Settings like your theme or saved cities are stored on your device only.

Data sources

• Time zones and daylight saving rules: the IANA tz database (release 2026e).
• City search: GeoNames, licensed under CC BY 4.0; time zones assigned with timezone-boundary-builder boundaries.
• Major cities and populations: Natural Earth via the city-timezones dataset. Maps: Natural Earth (public domain).
• Clock digits: the DSEG7 font by Keshikan (SIL Open Font License).

Contact

Found a bug or want a new tool? Email [email protected].