<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script>
jQuery(document).ready(function(){
jQuery('.form-file input').each(function () {
$this = jQuery(this);
$this.on('change', function() {
var fsize = $this[0].files[0].size,
ftype = $this[0].files[0].type,
fname = $this[0].files[0].name,
fextension = fname.substring(fname.lastIndexOf('.')+1);
validExtensions = ["jpg","pdf","jpeg","gif","png","doc","docx","xls","xlsx","ppt","pptx","txt","zip","rar","gzip"];
if ($.inArray(fextension, validExtensions) == -1){
alert("This type of files are not allowed!");
this.value = "";
return false;
}else{
if(fsize > 3145728){/*1048576-1MB(You can change the size as you want)*/
alert("File size too large! Please upload less than 3MB");
this.value = "";
return false;
}
return true;
}
});
});
});
</script>
</head>
<body>
<form>
<div class="form-file">
<label for="file-upload" class="from-label">File Upload</label>
<input class="form-control" name="file-upload" id="file-upload" type="file">
</div>
</form>
</body>
</html>
Here is complete answer for checking file size and file extension. This used default file input field and jQuery library.
Working example : https://jsfiddle.net/9pfjq6zr/2/