How to Use a Fullscreen Digital Clock

Turn any spare screen into a big digital clock with 12 or 24-hour time, seconds and the date. Free online clock, no sign-up, works offline in your browser.

Updated 4 min read By CodingEagles
Free tool Digital Clock Online A big fullscreen clock with 12 or 24-hour time, seconds and the date. Open tool

A fullscreen digital clock turns any spare screen into a clear time display. To use it, open the digital clock, choose 12 or 24-hour time, decide whether to show seconds and the date, then tap fullscreen. The digits scale to fill the display, so an old monitor or tablet becomes a desk clock you can read from across the room.

It runs in your browser, free, with no sign-up, and keeps working offline once loaded.

Set it up the way you want

  1. Pick 12-hour for a clock with AM and PM, or 24-hour for a single 0 to 23 reading.
  2. Turn Seconds on if you want the live tick, or off for a calmer face.
  3. Turn Date on to show the weekday and full date under the time.
  4. Tap fullscreen to fill the screen and hide everything else.

Your choices are saved on your device, so the clock opens the way you left it next time. Nothing is sent anywhere to do that.

Good places to use it

  • A spare screen as a desk clock. Stand an old tablet or monitor on your desk and leave the clock running fullscreen.
  • Studios and workspaces. A large, glanceable time that does not crowd the screen with anything else.
  • Calls and streams. A clean time display you can keep in view or share.
  • A bedside or kitchen clock. Repurpose a device you no longer carry around into a simple clock.

Why it stays accurate

The clock reads the time your device already keeps, which is itself synced by your operating system. That means it matches your phone and computer without you setting anything, and it does not drift the way a battery wall clock can. There is no server involved, so the time appears the instant the page loads.

For the best desk-clock setup, install the page to your home screen. It then opens in its own window like an app and keeps the time on a dedicated screen.

When you need more than one time zone

If you want to see the time in several cities at once rather than one local clock, the world clock shows them side by side with daylight saving handled. To wake or be reminded at a set time, the alarm clock adds a tone and a snooze.

Frequently asked questions

How does the digital clock know the right time?
It reads the clock your device is already set to, so it shows the same time as the rest of your computer or phone. There is nothing to set, and nothing is sent anywhere; the time comes straight from your own device.
Can I switch between 12 and 24-hour time?
Yes. A single toggle switches between a 12-hour clock with AM and PM and a 24-hour clock. Your choice, along with whether seconds and the date show, is remembered on your device for next time.
How do I make the clock fill the whole screen?
Tap the fullscreen button and the clock expands to fill the display, hiding everything else for a clean face. Press escape or the button again to come back.
Will the clock keep running if my internet drops?
Yes. Once the page has loaded it runs entirely on your device, so it keeps showing the correct time with no connection. You can install it to your home screen and open it like an app.

Ready to try it?

A big fullscreen clock with 12 or 24-hour time, seconds and the date. Free, in-browser, and 100% private — your data never leaves your device.

Open the Digital Clock Online