How do I make a clock fill the whole screen?

Open the clock page and press F11 on Windows or Linux, or Control-Command-F on macOS, then press Escape to leave fullscreen again. On a tablet or phone, use the browser share menu to add the page to your home screen so it launches with no address bar at all.

How big should the digits be on a wall-mounted screen?

Allow roughly one inch of digit height for every ten feet of viewing distance, or about 25 mm for every three metres. Measure from the furthest point anyone will read it from and size up from there. A bolder face carries further than a thin one at the same height.

Can I hide the mouse pointer on a clock display?

Move the pointer to the edge of the screen and stop moving it. Browsers hide the cursor automatically after a few seconds of inactivity in fullscreen and bring it back on the next movement. Kiosk mode goes further, removing the toolbar and tab strip as well.

Will my clock settings be remembered next time?

Yes. Format, seconds, colour, font and size are saved in your browser's localStorage on that device, so the page reopens exactly as you left it. Private windows and clearing site data will reset them, so set up any long-running display in an ordinary window.

Fullscreen Digital Clock on Your Desktop

A second monitor sitting blank is wasted space, and an old laptop shut in a drawer is worse. A fullscreen digital clock turns any idle screen into something genuinely useful: a large, uncluttered readout that can be read from the other side of the room without unlocking a phone or squinting at a taskbar. It needs no installation and no account, only a browser, a spare display and about two minutes of setup.

This guide covers how to enter fullscreen in each major browser, how to size the digits for the room you are actually standing in, how to hide the cursor and every other distraction, and how to stop the machine going dark an hour later. Open the large digital clock in a spare window and follow along; every step applies whether the fullscreen clock ends up on a monitor, a tablet or a television.

Why Use a Fullscreen Digital Clock Instead of the System Clock?

Because the system clock is tiny and lives in a corner. A fullscreen digital clock uses the whole panel, so the digits can be ten or twenty times the height of a taskbar clock and stay readable across a room, a workshop or a studio.

There are quieter advantages too. A dedicated screen showing nothing but the time carries no notifications, no unread badges and no temptation to check something else. That is the same reasoning behind digital signage in airports and hospital corridors: one piece of information, presented large, at a glance cost of nearly zero. A fullscreen clock in a browser is simply the cheapest way to build one, since almost every device already in the house can display it.

How Do You Go Fullscreen in Each Browser?

Press F11 on Windows and Linux, or Control-Command-F on macOS. Safari also offers the green window button. On tablets and phones, add the page to the home screen and it opens with no browser chrome at all.

Chrome and Edge on Windows or Linux: press F11, or open the three-dot menu and choose the fullscreen icon in the zoom row.
Firefox on Windows or Linux: press F11, or use the hamburger menu and the fullscreen arrows.
Any browser on macOS: press Control-Command-F, or hold the pointer over the green traffic-light button and choose Enter Full Screen.
Safari on macOS: once in fullscreen, use the View menu and switch off Always Show Toolbar in Full Screen, so nothing slides down when the pointer nears the top edge.
iPad and iPhone: tap Share, then Add to Home Screen. Launching from that icon opens the clock without an address bar.
Android: use the Chrome menu and Add to Home screen for the same result.

The button on the page itself uses the browser's Fullscreen API, the same mechanism a video player uses. Browsers deliberately require a click or a tap before granting it, so no page can seize the whole screen unprompted, and a fullscreen clock only fills the panel once you ask it to. Pressing Escape always returns you to the ordinary window.

Kiosk Mode for a Permanent Display

If a screen exists only to show the time, kiosk mode is tidier than fullscreen. Launching Chrome or Edge with the kiosk switch and the clock's address opens the page with no window controls, no tab strip and no route to another site. Combine that with a machine set to log in automatically and you have an appliance: power on, fullscreen clock appears. Most small digital signage installations work exactly this way, and the arrangement survives a reboot far better than a hand-placed window does.

Sizing the Digits for the Room

A rule borrowed from sign making works well here: allow roughly one inch of digit height for every ten feet of viewing distance, or about 25 mm for every three metres. A fullscreen clock read from six metres wants digits around 50 mm tall.

Measure from the furthest place you will actually look at it, then raise the size until the digits fill that height. On a 27-inch monitor at desk distance almost any setting works; on a 55-inch panel at the end of a workshop it matters a great deal. Legibility at distance depends on stroke weight as much as height, so a slightly bolder face carries further than a thin one scaled up to match. A fullscreen digital clock has the entire panel to work with, so there is rarely a reason to be timid about size. If the display also shows a date or a seconds row, size the hours and minutes first and let everything else stay secondary.

Hiding the Cursor and the Clutter

Park the pointer against an edge of the screen and leave it there. Most browsers fade the cursor after a few seconds of stillness in fullscreen, and it returns the instant the mouse moves.

Then remove everything else that might interrupt. Switch on Do Not Disturb or Focus so notification banners never slide across the digits, since a fullscreen clock with a message draped over it is worse than no clock at all. Turn off the system screensaver, which would otherwise replace your clock with drifting photographs. Close other tabs in the same window so no favicon animates in the corner. On a laptop being used as a wall display, a bright keyboard backlight and a webcam indicator are worth disabling too.

How Do You Keep a Fullscreen Digital Clock Running?

Stop the computer from sleeping. Set the display timeout to Never in Windows Power and battery settings, or in the macOS Lock Screen settings, and turn on the page's keep-awake option, which asks the browser's Screen Wake Lock API to hold the panel lit.

The Wake Lock API is convenient but limited. It only works over a secure connection, and the browser releases the lock the moment the tab is hidden or the window is minimised, so treat it as a helper on top of correct power settings rather than a replacement for them. Running a fullscreen clock continuously has costs of its own, from electricity to the faint permanent image that static digits can leave on an OLED, both of which are covered in the guide to keeping your display awake and in the notes on using a clock as a screensaver.

Settings That Stick Between Sessions

Preferences such as 12 or 24-hour format, whether seconds appear, the colour, the font and the size are stored in the browser's localStorage, so the fullscreen digital clock you set up in January is exactly the one you get back in June. Nothing is uploaded and no account is involved.

Two things clear them: browsing in a private window, and clearing site data for the page. If a display is meant to run for months, set it up once in an ordinary window and then leave it alone. If you cannot decide between formats, the comparison of the 12 hour vs 24 hour display covers which suits a shared room, and for a bedroom the dimmed red night-mode clock is a better fit than a bright white face.

Conclusion

A fullscreen digital clock is one of the few genuinely useful things to do with a screen you were not otherwise using. Enter fullscreen with F11 or Control-Command-F, size the digits by the distance you will read them from, hide the cursor and the notifications, and set the display never to sleep so it is still there in the morning. Open the fullscreen clock display to set yours up, or start from the digitalclock.now homepage and pick the mode that fits the room.

How to Put a Fullscreen Digital Clock on Your Desktop