Search code examples
javascriptfile-upload

Validate image type using javascript


i have a form like this:

<form method=post src=upload enctype="multipart/form-data">
    <input name="img1" id="img1" type="file">
    <input type="submit" value="Upload">
</form >

Please how can I valid this form using javascript so that only jpg files are uploaded. thanks for reading.


Solution

  • You can bind the onsubmit event of your form, and check if the value of your file input ends with ".jpg" or ".jpeg", something like this:

    window.onload = function () {
      var form = document.getElementById('uploadForm'),
          imageInput = document.getElementById('img1');
    
      form.onsubmit = function () {
        var isValid = /\.jpe?g$/i.test(imageInput.value);
        if (!isValid) {
          alert('Only jpg files allowed!');
        }
    
        return isValid;
      };
    };
    

    Check the above example here.