Build a live <div>-and-JS countdown to any ISO target timestamp. Part of the DevTools Surf developer suite. Browse more tools in the Date / Time collection.
Use Cases
Marketing teams building product launch countdown pages
Event organizers embedding live countdowns in landing pages
E-commerce devs creating flash sale timer widgets
Educators building exam deadline countdown displays
Tips
Set the target timestamp in ISO 8601 format for precision
Copy the generated HTML/JS snippet into any web page
The countdown updates live in the browser via setInterval
Fun Facts
The JavaScript Date object, which powers browser countdowns, counts milliseconds since January 1, 1970 (Unix epoch) and will overflow its 32-bit integer limit on January 19, 2038.
The first website countdown timer is believed to have appeared for the Y2K millennium event in 1999, when thousands of sites displayed days/hours/minutes to January 1, 2000.
requestAnimationFrame, introduced in 2011, replaced setInterval for smooth countdown animations — it syncs updates to the display's refresh rate (typically 60fps).
FAQ
What does it output?
HTML + JavaScript for a self-contained countdown. Drop into any page; no framework needed.
Customize the display?
Days/hours/minutes/seconds visible or not, number formatting, label text. Plus CSS for color and spacing.
What happens when the countdown reaches zero?
Configurable message (default: 'Event is live!'). Plus optional redirect to a specified URL.
Timezone handling?
The target timestamp is ISO 8601 (UTC). Countdown shows time remaining from each visitor's local clock. No zone confusion.
