Convert an image to Base64 Encoded

Submit an image to convert it to a Base64 encoded string

File to convert 
<form>
  <input accept="image/png, image/jpeg, image/svg+xml" name="file" required type="file" />
  <button>Convert!</button>
</form>
<script>
  document.querySelector('form').addEventListener('submit', (event) => {
    event.preventDefault();

    const file = event.target.file.files[0];

    const reader = new FileReader();

    reader.onload = (event) => {
      const base64EncodedImage = event.target.result;
      alert(base64EncodedImage);
    };

    reader.readAsDataURL(file);
  });
</script>