Countdown Timer
A free online countdown timer with presets, a sound alarm, fullscreen mode and a shareable link. Runs accurately even in a background tab.
00:00:00
Ready
Duration
Count down to a date
Copy the address bar to share this countdown with someone else.
What this tool is for
Count down to a duration or to a specific date. The timer is driven by wall clock arithmetic rather than by counting ticks, so it stays accurate when the tab is in the background and the browser throttles timers, which is where most web countdowns drift.
How to use it
- Set a duration, or pick a target date and time.
- Start it. The remaining time also appears in the tab title, so it is visible while you work elsewhere.
- Use fullscreen for a presentation, and copy the link to share the same countdown with someone else.
Frequently asked questions
Does it keep running if I switch tabs?
Yes. The remaining time is computed from the end timestamp, so background throttling changes how often the display refreshes but never the result.
Will the alarm sound?
Yes, provided you have interacted with the page, which browsers require before allowing audio. Starting the timer counts as that interaction.