Create countdown timers for events, exams, and holidays
Create live countdown timers for any event. Whether it is New Year, a birthday, an exam, or a product launch, our countdown timer shows you exactly how much time is left. Share your countdown with friends using a unique link.
setInterval to a minimum of about 4 ms, and throttle inactive tabs to roughly one tick per second — or freeze them entirely. A correct countdown therefore stores the target timestamp and recomputes the remaining time on every frame, rather than counting down a variable.| Situation | What happens |
|---|---|
Active tab, setInterval(fn, 1000) | Drifts a few milliseconds per tick; accumulates visibly over an hour |
| Intervals under 4 ms | Clamped to 4 ms by every major browser |
| Inactive background tab | Throttled to roughly 1 tick per second, often much less |
| Long-idle background tab | Chrome may freeze timers entirely after about 5 minutes |
| Laptop sleeps or lid closes | Timers stop; on wake the clock has jumped |
| Mobile browser, screen off | JavaScript is generally suspended altogether |
| Heavy main-thread work | Ticks queue behind it and fire late in a burst |
const end = Date.now() + durationMs.remaining = end − Date.now(). Never decrement a counter.requestAnimationFrame for smooth display, and keep a setInterval as a fallback for when the tab is hidden.visibilitychange and recompute immediately when the tab becomes visible — this is what makes a timer survive being backgrounded.| Use | Typical duration | Note |
|---|---|---|
| Tea steeping | 3–5 min | Green tea 2–3 min, black 3–5 min |
| Boiled egg — soft | 6 min | From boiling water, medium egg |
| Boiled egg — hard | 10–12 min | Then cold water to stop the cooking |
| Pasta | 8–12 min | Check the packet; altitude adds time |
| Pomodoro work block | 25 min | See the Pomodoro technique |
| Exercise interval (HIIT) | 20–40 s work, 10–20 s rest | Tabata is 20/10 × 8 |
| Plank hold | 30–120 s | |
| Presentation slot | 5, 10, 20 min | Ignite is 5 min; TED is 18 min |
| Instant noodles | 2–3 min | |
| Toothbrushing | 2 min | The figure dentists actually recommend |
If the tab is throttled, several seconds can pass between ticks. A timer that decrements a variable will simply lose that time and finish late by exactly the amount it was throttled. A timer that recomputes from a stored end timestamp will instead jump — going from 0:42 straight to 0:31 when the tab regains focus. The jump looks like a bug and is in fact the correct behaviour: the second timer is telling the truth about how much time has actually elapsed.
In an active tab, accurate to within a few milliseconds per tick, which is fine for human purposes. In a background tab they are throttled to about one tick per second or frozen entirely, so a timer must recompute from a stored end timestamp rather than counting down a variable.
A correctly built one will report the right remaining time when you come back, because it recomputes from the target timestamp. Its visual updates and its alarm may be delayed while the tab is hidden, and on a phone with the screen off JavaScript is usually suspended altogether.
Browsers block audio until the user has interacted with the page, so a timer you never clicked cannot play its alarm. Backgrounded and throttled tabs can also delay the sound. Grant notification permission if the alert matters.
About 4 milliseconds. Every major browser clamps setTimeout and setInterval to that minimum after a few nested calls, so anything needing finer timing should use requestAnimationFrame or the Web Audio clock.
Two minutes, twice a day, which is the interval dental associations consistently recommend — and the reason a two-minute preset appears on almost every countdown tool.
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