---
title: How to Create a Countdown Timer
---
## How to Create a Countdown Timer
### Creation
Start by building the countdownTimer function.
```javascript
function startCountdown(seconds){
var counter = seconds;
var interval = setInterval(() => {
console.log(counter);
counter--;
if(counter < 0 ){
// The code here will run when
// the timer has reached zero.
clearInterval(interval);
console.log('Ding!');
};
}, 1000);
};
```
### Execution
Now to start the timer we provide `startCountdown()` with a number value as an argument which represents the seconds to countdown.
```javascript
startCountdown(10);
// Console Output //
// 10
// 9
// 8
// 7
// 6
// 5
// 4
// 3
// 2
// 1
// 0
// Ding!
```
### Live Example
Codepen - Countdown Timer
### More Resources
Methods used:
* setInterval()
* clearInterval()