Time shown as actual binary — each decimal digit of the hour, minute, and second is drawn as its own column of lit and unlit dots, using the same 8-4-2-1 BCD (binary-coded decimal) encoding real binary clocks use. Pick from eight dot colors, toggle seconds and date, and go fullscreen — all free, in a browser tab.
Four dots, one rule, and you'll never need to stop and count again.
Each column is one decimal digit. Read the lit dots top to bottom and add up their values — 8, 4, 2, and 1. Any digit from 0 to 9 comes from some combination of those four.
Say the clock reads 14:32. The hour columns light "1" (=1) then "4" (=4) — that's 14. The minute columns light "2" and "1" together (=3) then "2" (=2) — that's 32. Same rule, every column, every time.
Glance at it a few times a day instead of drilling — you already know what time it should say, so you get instant feedback on whether you read the dots right.
Once the 8-4-2-1 rule sticks, reading a shared screen cold in front of someone is a neat flex — most people need a beat the first try, then can't stop doing the math in their head afterward.
Four steps between you and a working set of blinking lights.
The dots are already lit the moment the page loads — no app, no extension, and the layout holds up identically on a monitor, a tablet, or a phone propped on a desk.
Settings has all eight dot colors behind a single tap, saved locally so your pick is still there whenever you come back.
The 12/24-hour toggle, seconds, and the date live as three independent switches — flipping one leaves the dot columns you're not looking at untouched.
Fullscreen strips the browser away entirely, leaving just the dot columns on screen; pair it with Keep Screen On if it's sitting on a shelf unattended.
Everything the binary clock actually does.
Every dot pattern is the real binary-coded-decimal representation for that digit — 0 is 0000, 9 is 1001 — the same convention actual hardware binary clocks use, not a made-up pattern that just looks binary-ish.
Switching formats changes which hour digit gets encoded (14 becomes 02, say) — the 8-4-2-1 rule and BCD columns work exactly the same underneath either way.
Eight lit-dot colors to pick from in Settings, from a cool cyan to a warm amber, each rendered on the same dark background.
One tap hides every browser control, leaving nothing on screen but the dot grid itself.
The same Wake Lock mechanism used elsewhere on this site holds the tab awake here too — worth flipping on if the display is going to sit somewhere unattended.
Resize the browser window or pull it up on a phone — there's no fine detail in a dot grid to lose, so it stays legible shrunk down or blown up.
Nothing here needs a login or a network call once the page has loaded — every dot is drawn locally, and your preferences stay put on this device.
The details people ask once they've got the basics down.
Two per number, so four columns for hours and minutes, six once you turn seconds on — each pair is the tens and ones digit of that number, both read with the same 8-4-2-1 rule.
A single binary number for the whole time would need a different number of digits depending on the hour, which shifts the whole layout throughout the day. BCD keeps each decimal digit in its own fixed column instead.
Same underlying idea — BCD, lit versus unlit — but this one is a webpage instead of a soldered circuit board. No wiring, no case to build, just open the tab.
Yes — toggle it on in Settings alongside seconds, independent of everything else on the display.
It's off by default — switch it on in Settings if this is going to sit unattended on a shelf or rack, otherwise your device's own sleep timer stays in charge.
The glow colors pair naturally with RGB keyboards, case lighting, or a homelab rack — Green and Amber lean toward a classic terminal look (the two phosphor colors real CRT terminals actually used), while Red, Blue, Purple, Cyan, and Pink lean more decorative, closer to RGB gaming gear than any real terminal hardware.
Prefer a mechanical flip-card, retro pixel-grid, or neon gradient look instead? See the Flip Clock Online, Pixel Clock Online, or Neon Clock Online, or open the full Digital Clock to flip between every theme and setting.