JSFiddle - React, Tailwind, and code Playground

HTML

<canvas  id='example'></canvas>
  <img id="imageId" src="" >

JavaScript

function getBase64Image(img) {
    var canvas = document.createElement("canvas");
    canvas.width = img.width;
    canvas.height = img.height;

    var ctx = canvas.getContext("2d");
    ctx.drawImage(img, 0, 0);

    var dataURL = canvas.toDataURL("http://shrek.by/Photo/Shrek.jpg");

    return dataURL.replace(/^data:image\/(png|jpg);base64,/, "");
}




var image = document.getElementById('imageId');
var b64image = getBase64Image(image);
localStorage.setItem('imageIdCached', b64image);