Does the clock keep ticking when I switch tabs?

No — it pauses when the tab is hidden and resumes when you come back. This saves CPU and battery without drift because the next tick reads real time.

Is this a countdown timer?

No, this is a wall clock that reads the current time. If you need a countdown to a specific moment, use the Countdown Timer Large tool instead.

Can I embed this in OBS?

Yes. Add a Browser source pointing at the page URL, then crop to the stage area. Any custom background color can be keyed out for chroma transparency.

Why don't I see a smooth second-hand?

This is a digital clock — seconds tick once per second. A smooth analog second-hand is a separate tool on the roadmap.

How does the timezone dropdown work?

Choose any IANA zone (like Asia/Tokyo) and the clock formats using that timezone via the browser's Intl engine. No server call is made.

What timezone does Auto use?

Whichever timezone your operating system is configured for. This is the default and what most users want.

Why is there a slight delay when I switch timezones?

The next tick picks up the new zone. Because the clock ticks four times a second, the switch happens within 250 ms.

Can screen readers read the clock?

Yes. An aria-live region mirrors the current time in plain text so assistive tech can announce updates without visual clutter.

Will it work on a Smart TV?

Yes, on any modern browser that supports Intl.DateTimeFormat. Smart-TV browsers that ship in the last 5 years are supported.

Do I need to refresh when daylight saving changes?

No — the Intl engine handles DST transitions automatically based on the selected IANA zone.

Big Clock Display

A free fullscreen digital clock for classrooms, livestreams, kiosks, and events. Giant HH:MM:SS with timezone, color, and 12/24-hour controls.

13:01:34

Wednesday, June 3, 2026

What is Big Clock Display?

Big Clock Display is a zero-setup online clock. Pick a format, pick a timezone, pick colors — the page renders one enormous digital HH:MM:SS that fills the stage and reads from across a room. Everything runs in your browser. Nothing is uploaded, nothing is installed.

It complements the other Large Text tools: Large Text Display shows one static phrase, Fullscreen Text cycles through slides, and LED Scrolling Text pushes a headline across the screen. Big Clock Display adds “the actual current time” to the toolbox.

Under the hood, every tick reads new Date(), formats with the browser’s native Intl.DateTimeFormat in the chosen IANA timezone, and updates three short strings. There’s no canvas, no animation loop, no battery drain.

Tips & best practices

Hide seconds for calm displays. A reception desk or broadcast standby screen reads better without the once-per-second blink.
Use the date subtitle for remote teams. The long-format date next to a timezone like Asia/Tokyo is a lightweight way to coordinate “what day is it there”.
High-contrast wins. Sky-blue on near-black or amber on charcoal both read well. Avoid light-on-light; the digits are large, but legibility still depends on contrast.
Fullscreen early. The clock looks dramatically more purposeful at full size. OBS users should fullscreen first, then crop to the needed area.
Respect motion-sensitive viewers. If you’ve got one in the room, the colon blink honors prefers-reduced-motion — no extra setup needed.
Do Not Disturb on mobile. A phone clock that flashes up call notifications is not the clock you wanted.

How to use it

1
Pick format and options Choose 12-hour or 24-hour, toggle seconds and date on or off, and select a timezone — Auto reads your device, or pick from the IANA dropdown.
2
Customize colors Digits and background each have their own color picker. High-contrast defaults work out of the box.
3
Go fullscreen Click the fullscreen button. Press Esc to exit. The clock keeps ticking; it pauses CPU-cheap when the tab is hidden.

Use Cases

Classroom clock
Project a giant HH:MM on the whiteboard display. Students see remaining time without squinting at the small bar at the top of the slide.
Livestream standby card
OBS browser source pointed at this page. Adds a ticking clock to intermission screens so viewers know the stream is live.
Event check-in kiosk
Tablet at the registration desk shows both the current time and today's long-format date — no printed signage needed.
Gym and yoga studio
Back wall of the studio runs a full-screen clock that works from a phone, no installed app, no distracting ads.
Meeting room timer
Shared meeting screen shows the current time during standups; the date subtitle helps remote colleagues join the right day.
Remote-team timezone reference
Switch the timezone dropdown to your teammate's city to glance at their local time before scheduling a ping.
Coworking space reception
Rotating display at the front desk. Clean, brand-friendly colors make it feel purposeful rather than utilitarian.
Broadcast studio reference clock
Producers and camera ops need an oversized master clock without buying a hardware one. Fullscreen and done.

Features

12-hour or 24-hour
Toggle once, remembered for the session. AM and PM render as a small superscript so the hour-minute pair stays the visual anchor.
Optional seconds
Hide seconds for a calmer display or show them for timing-precision moments like a livestream countdown.
Localized date subtitle
Long-format date with weekday below the clock, rendered via the browser's Intl engine — Spanish, Chinese, Japanese, and Korean all read naturally.
Timezone picker
24 curated IANA zones covering the major English, Chinese, Japanese, and Korean speaking regions. Or leave it on Auto.
Digit and background colors
Pair your brand colors or match room lighting. Defaults are sky-blue on near-black for maximum legibility.
Fullscreen ready
One click sends the clock to the full screen. Esc to exit. Tab-change pauses the tick to save CPU and battery.
Works offline after first load
Static page, zero server round-trips for the clock itself. Good for venues with flaky Wi-Fi.
Nothing uploaded
Everything ticks locally in your browser. No analytics on the tool controls, no upload of your settings.

Compatible Platforms

iPhone (Safari / Chrome)
Android (Chrome / Firefox)
iPad and Android tablets
Windows (Chrome / Edge / Firefox)
macOS (Safari / Chrome)
Linux
Smart-TV browsers
Chromebook
OBS Studio (Browser Source)

Related Tools

FAQ

Does the clock keep ticking when I switch tabs?: No — it pauses when the tab is hidden and resumes when you come back. This saves CPU and battery without drift because the next tick reads real time.
Is this a countdown timer?: No, this is a wall clock that reads the current time. If you need a countdown to a specific moment, use the Countdown Timer Large tool instead.
Can I embed this in OBS?: Yes. Add a Browser source pointing at the page URL, then crop to the stage area. Any custom background color can be keyed out for chroma transparency.
Why don't I see a smooth second-hand?: This is a digital clock — seconds tick once per second. A smooth analog second-hand is a separate tool on the roadmap.
How does the timezone dropdown work?: Choose any IANA zone (like Asia/Tokyo) and the clock formats using that timezone via the browser's Intl engine. No server call is made.
What timezone does Auto use?: Whichever timezone your operating system is configured for. This is the default and what most users want.
Why is there a slight delay when I switch timezones?: The next tick picks up the new zone. Because the clock ticks four times a second, the switch happens within 250 ms.
Can screen readers read the clock?: Yes. An aria-live region mirrors the current time in plain text so assistive tech can announce updates without visual clutter.
Will it work on a Smart TV?: Yes, on any modern browser that supports Intl.DateTimeFormat. Smart-TV browsers that ship in the last 5 years are supported.
Do I need to refresh when daylight saving changes?: No — the Intl engine handles DST transitions automatically based on the selected IANA zone.