convert input image to base64 javascript code example

Example 1: convert file into base64 in javascript

function getBase64(file) {
  return new Promise((resolve, reject) => {
    const reader = new FileReader();
    reader.readAsDataURL(file);
    reader.onload = () => resolve(reader.result);
    reader.onerror = error => reject(error);
  });
}

var file = document.querySelector('#files > input[type="file"]').files[0];
getBase64(file).then(
  data => console.log(data)
);

Example 2: javascript base64 encode file input

var fileInput = document.getElementById('#myInputID');

var reader = new FileReader();
reader.readAsDataURL(fileInput.files[0]);

reader.onload = function () {
	console.log(reader.result);//base64encoded string
};
reader.onerror = function (error) {
	console.log('Error: ', error);
};

Example 3: convert an image into Base64 string using JavaScript

function getBase64Image(src, callback, outputFormat) {
      const img = new Image();
      img.crossOrigin = 'Anonymous';
      img.onload = () => {
        const canvas = document.createElement('canvas');
        const ctx = canvas.getContext('2d');
        let dataURL;
        canvas.height = img.naturalHeight;
        canvas.width = img.naturalWidth;
        ctx.drawImage(img, 0, 0);
        dataURL = canvas.toDataURL(outputFormat);
        callback(dataURL);
      };

      img.src = src;
      if (img.complete || img.complete === undefined) {
        img.src = "data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///ywAAAAAAQABAAACAUwAOw==";
        img.src = src;
      }
    }