This example shows how to use the MathJax.mathml2svg() function to process user input in MathML format, producing SVG output.
The key lines are
<script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/mml-svg.js"></script>
<script>
function convert() {
//
// Get the MathML input string, and clear any previous output
//
var input = document.getElementById("input").value.trim();
output = document.getElementById('output');
output.innerHTML = '';
//
// Convert the MathMl to an HTML node and append it to the output
//
output.appendChild(MathJax.mathml2svg(input));
//
// Then update the document to include the adjusted CSS for the
// content of the new equation.
//
MathJax.startup.document.clear();
MathJax.startup.document.updateDocument();
}
</script>
When the user presses the Render MathML button, the convert() function above runs. The comments in the code explain how the conversion process is handled. Unlike the similar TeX examples, this example uses synchronous processing, rather than a promise-based one, since there is no equivalent to the \require macro in MathML input to cause an extension to be dynamically loaded. That also means it is unnecessary to disable the render button, since the convert() function will complete before any other user interaction can take place.