How to Validate File Size before Upload with JavaScript

The validation helps to restrict uploading large files or empty files to the server. We will share with you a pretty easy way to limit size of upload file in a webpage form using HTML and Javascript/jQuery.

File Size Validation Using Javascript Example

Javascript code

function checkFileNewValidation() {

var image = document.getElementById("image");

if (typeof (image.files) != "undefined") {
var size = parseFloat(image.files[0].size / (1024 * 1024)).toFixed(2);
if(size > 2) {
alert('Please select image size less than 2 MB');
}else{
alert('success');
}
} else {
alert("This browser does not support HTML5.");
}

}

Example : File upload required validation in javascript

index.html

<!DOCTYPE html>
<html lang="en">
<head>
<title>File Size Validation Using Javascript Example</title>
<meta charset="utf-8">
<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.5.0/css/bootstrap.css">
</head>
<body class="bg-dark">
<div class="continer">
<div class="row">
<div class="col-md-6 offset-md-3">
<div class="card">
<div class="card-header">
<h5>File Size Validation Using Javascript Example</h5>
</div>
<div class="card-body">
<form method="post" name="frmAdd" id="frmAdd">
<label for="image">Image:</label>
<input type="file" name="image" class="form-control" id="image" value="" onchange="checkFileNewValidation()"><br/>
<button type="submit" class="btn btn-success">Submit</button>
</form>
</div>
</div>
</div>
</div>
</div>
</body>
<script type="Javascript">
function checkFileNewValidation() {
var image = document.getElementById("image");
if (typeof (image.files) != "undefined") {
var size = parseFloat(image.files[0].size / (1024 * 1024)).toFixed(2);
if(size > 2) {
alert('Please select image size less than 2 MB');
}else{
alert('Good Luck, success');
}
} else {
alert("This browser does not support HTML5.");
}
}
</script>
</html>

I hope you get an idea about Javascript validate file size before upload.

This blog post was originally published at: https://www.pakainfo.com

#javascript