Trigger Button Click On Page Load JavaScript

In this tutorial we will learn how to Trigger a Button Click On Page Load using JavaScript. onload Event can be used for this purpose which occurs when a HTML page or object has been loaded.

HTML Code

HTML Code is given below, in this code we have used onload event inside the body tag. We have also used onclick event inside the HTML button, which will display the alert message on button click.

<!DOCTYPE html>
<html>
<head>
<title>Trigger Button Click On Page Load JavaScript</title>
<meta content="width=device-width, initial-scale=1" name="viewport" />
</head>
<body onload="triggerBtnClick()">
    
<button id='btn' onclick="alert('Button Clicked!')">Button</button>    
<script src="script.js"></script>    
</body>
</html>

JavaScript Code

Take a look at the JavaScript code, JavaScript function triggerBtnClick() will be executed once the page has been loaded, this is done using onload page event.

This function will trigger a button click which will execute a script written inside button tag.

<script>
function triggerBtnClick()
{
  document.getElementById("btn").click(); 
}
</script>

onload Event

onload Event is used to attach an onload event with the HTML object. It executes a JavaScript function or script once the object or page has been loaded completely.

You can also use addEventListener() method to add the onload event to webpage.

<script>
  window.addEventListener('load', function () {
  document.getElementById("btn").click();
})
</script>

Demo

Video Tutorial

Watch video tutorial on Trigger Button Click On Page Load with JavaScript.

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