How To Validate Upload File Type Using Javascript

WebSolutionStuff | Aug-03-2020 | Categories : Laravel PHP

This article will show us how to validate upload file type using javascript. Using this post we can easily check the selected file extension with allowed file extensions and we can restrict the user to upload only the allowed file types.

So, let's see file type validation in jquery or file upload type validation using javascript.

laravel also provides file type validation in the controller but it is server-side only which means we can receive validation messages after the form submits, here I will give you an example to check file type before submitting data in the form using javascript. Currently, we have checked only specific file extensions like ".txt", ".csv" etc... or you can use all file types like "image/* ".

So, add the below code in the javascript.

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <title>File upload type validation in javascript - websolutionstuff.com</title>
  <link href="https://stackpath.bootstrapcdn.com/bootstrap/3.4.1/css/bootstrap.min.css" rel="stylesheet">
  <script src="https://code.jquery.com/jquery-3.5.1.min.js"></script>  
</head>
<body>
  <h3 style="text-align: center;">File upload type validation in javascript - websolutionstuff.com</h3>
  <div class="col-md-6 col-md-offset-5"><br>
  <input type="file" name="file"  id="filesizecheck"><br>
  <span id="error-message" class="validation-error-label"></span>
  </div>
</body>
</html>
<script type="text/javascript">
  $(document).ready(function(){
    $('#filesizecheck').on('change',function(){
      myfiles = $(this).val();
      var ext = myfiles.split('.').pop();
      if(ext == "txt" || ext == "png"){
        $('#error-message').css("display","none");
      }else{
        $('#error-message').html("Only allow valid file inputs.");
        $('#error-message').css("display","block");
        $('#error-message').css("color","red");
      }
    });
  });
</script>

And you will get output like the below image.

file upload type validation