You can tweak the configuration, or even give a complete configuration, using a <script> tag with type="text/x-mathjax-config". For example: <script type="text/x-mathjax-config"> MathJax.Hub.Config({ jax: ["input/AsciiMath","input/TeX","output/SVG"], extensions: ["asciimath2jax.js","tex2jax.js"], }); </script> Note: If you give a complete configuration, you should not include ?config=... in the script that loads MathJax.js Note: The configuration script should come before the script that loads MathJax.js itself.