function myFunction(eqn){ window.MathJax = { jax: ["input/TeX", "output/SVG"], extensions: ["tex2jax.js", "MathMenu.js", "MathZoom.js"], showMathMenu: false, showProcessingMessages: false, messageStyle: "none", SVG: { useGlobalCache: false }, TeX: { extensions: ["AMSmath.js", "AMSsymbols.js", "autoload-all.js"] }, AuthorInit: function() { MathJax.Hub.Register.StartupHook("End", function() { var mj2img = function(texstring, callback) { var input = texstring; var wrapper = document.createElement("div"); wrapper.innerHTML = input; var output = { svg: "", img: ""}; MathJax.Hub.Queue(["Typeset", MathJax.Hub, wrapper]); MathJax.Hub.Queue(function() { var mjOut = wrapper.getElementsByTagName("svg")[0]; mjOut.setAttribute("xmlns", "http://www.w3.org/2000/svg"); // thanks, https://spin.atomicobject.com/2014/01/21/convert-svg-to-png/ output.svg = mjOut.outerHTML; var image = new Image(); image.src = 'data:image/svg+xml;base64,' + window.btoa(unescape(encodeURIComponent(output.svg))); image.onload = function() { var canvas = document.createElement('canvas'); canvas.width = image.width; canvas.height = image.height; var context = canvas.getContext('2d'); context.drawImage(image, 0, 0); output.img = canvas.toDataURL('image/png'); callback(output); }; }); } mj2img(eqn, function(output){ const t = document.getElementById("target"); const i = document.createElement('img'); i.src = output.img; t.append(i); }); }); } }; } (function(d, script) { script = d.createElement('script'); script.type = 'text/javascript'; script.async = true; script.onload = function() { // remote script has loaded }; script.src = 'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js'; d.getElementsByTagName('head')[0].appendChild(script); }(document));

 <textarea onkeyup="myFunction(this.value)"></textarea> <div id="target"></div>