Seconds on or off
Show seconds when you are timing something, hide them for a calmer wall display.
Free Online Digital Clock with Seconds
Synchronizing with server time.
What this online digital clock does
It shows the current time with seconds, in 12- or 24-hour format, in a light or dark theme, and full screen from the Display Mode control under the clock. Digital Clock Online checks your device clock, applies a measured server-time offset, and warns you if the device itself is wrong. Free, nothing to install, no account.
12-hour or 24-hour
One tap switches the format. Your choice, and the seconds setting, are remembered on this device.
Full screen
The Fullscreen control fills your monitor with the clock. Press Esc or tap it again to leave.
Light and dark themes
Match the room. Dark for a desk at night, light for a projector or a bright classroom.
Synchronized with the server
The display uses a measured server-time offset and warns you if your device clock is off.
Clocks for other places
247 countries and 312 time zones each have their own page with a live clock.
How the clock stays accurate
When the page loads, your browser asks the server for an uncached timestamp, measures the round trip, and applies the resulting offset. The seconds advance locally so the display stays smooth, but the time shown is derived from that server measurement.
The site refreshes the measurement periodically and when you return to a tab. If your device is noticeably off, a warning shows the measured difference while the clock continues to display synchronized time. If the server cannot be reached, the status line labels the temporary device-time fallback and retries.
Digital Clock Online does not claim atomic precision. Network latency limits any browser clock to roughly the round-trip time, typically well under a second. What you get is a clock that tells you when your computer is wrong, which is the failure that matters in an exam hall or a trading desk.
Compare your time with other places
Compare your local time with the places below. The live comparison loads with the page; add or remove places and they are remembered in this browser.
| Place | Time zone | Standard offset |
|---|---|---|
| United Kingdom · London | Europe/London | UTC+00:00 |
| United States · Washington D.C. | America/New_York | UTC-05:00 |
| France · Paris | Europe/Paris | UTC+01:00 |
Common uses
Classrooms and exam halls
Put the clock on the projector with seconds showing. Everyone in the room sees the same time, and the drift warning tells you if the classroom PC is off.
A second monitor at work
Keep a large clock on a spare screen while you are on calls with people in other zones. The comparison table below shows how far ahead or behind they are.
Travel planning
Open a country or time zone page for where you are going and compare it with your local clock before you book a call or a train.
How to use it
Show or hide seconds
Use the Visibility control under the clock.
Pick 12h or 24h
Use the Time Format control. The setting applies immediately.
Go full screen
Use the Display Mode control. Esc brings the page back.
Pick a theme
The sun and moon switch in the header toggles light and dark. The site starts dark.
Frequently asked questions
Is this clock accurate?
It requests an uncached server timestamp, estimates network delay, and applies the measured offset to the display. It checks again periodically and after you return to the tab. If the device clock differs, you see the measured difference while the displayed clock remains synchronized.
Can I make the clock full screen?
Yes. Use the Display Mode control under the clock on this page. The clock fills the whole screen and keeps ticking, with the controls still available below it. Press Esc, or use the same control, to exit. The flip clock page has its own full-screen mode as well.
Do I need to install anything or sign up?
No. The clock runs in the browser. There is no download and no account. Your format and seconds choices are kept in a cookie on your device so they survive a reload, and the same choices apply on the flip clock page.
Can I show the time in another country?
Yes. Open the country or time zone pages from the header. Each one has a live clock, the zone's UTC offset and its daylight-saving rules. To see several places next to your own time, use the comparison section on this page; the places you add are remembered in this browser.
Does it work on phones and tablets?
Yes. The layout adapts to small screens and the controls work with touch. Full screen depends on the browser: Android browsers and iPad Safari support it, while Safari on iPhone does not offer it for web pages, so the control does nothing there. Everything else works the same.
Why does the clock show dashes for a moment?
The page is served without a time in it, because a time written into a cached page would be wrong by the time you read it. The digits fill in as soon as the script runs, usually within a second.
More ways to use Digital Clock Online
Flip clock
See the current time in a mechanical-style display.
Countdown timer
Set any duration and hear an alert at zero.
Pomodoro Timer
Run timed focus sessions and planned breaks.
Online stopwatch
Measure elapsed time and record lap splits.
Online alarm clock
Set one local alert while this page stays open.
Time by timezone
Browse 312 IANA time zones and their live clocks.