JSFiddle - React, Tailwind, and code Playground

HTML

Select file : <input type="file" id="flUpload" name="files[]" multiple/>
<br/><br/>
File Size is : <b><label id="lblSize" /></b>

CSS

body
{
    font-family: Arial;
    font-size : 10pt;
    padding : 10px;
}

JavaScript

$(document).ready(function() {
    
    

 if (window.File && window.FileReader && window.FileList && window.Blob) {
 alert('browser supports everything');
} else {
     var  fso = new ActiveXObject("Scripting.FileSystemObject");
    
  alert('The File APIs are not fully supported in this browser.');
} 
    
    
   $("#flUpload").change(function () 
   { 
         var name=$("#flUpload")[0].files[0].name;
       alert(" name" + name);
       var type=$("#flUpload")[0].files[0].type;
       alert(" type" + type);
       var lastmodified=$("#flUpload")[0].files[0].lastModifiedDate ? f.lastModifiedDate.toLocaleDateString() : 'n/a';
       alert(" lastmodified" + lastmodified);
      
        

       
     var iSize = ($("#flUpload")[0].files[0].size / 1024); 
     if (iSize / 1024 > 1) 
     { 
        if (((iSize / 1024) / 1024) > 1) 
        { 
            iSize = (Math.round(((iSize / 1024) / 1024) * 100) / 100);
            $("#lblSize").html( iSize + "Gb"); 
            $("#lblSize").html(" \n "+ "Name of the FIle " + name);
        }
        else
        { 
            iSize = (Math.round((iSize / 1024) * 100) / 100)
           $("#lblSize").html( iSize + "Mb"); 
            
        } 
     } 
     else 
     {
        iSize = (Math.round(iSize * 100) / 100)
        $("#lblSize").html( iSize  + "kb"); 
         
     }    
  }); 
});