# v2-compatibility.html

This example shows how to set up MathJax version 3 to act somewhat more like MathJax version 2.

The main actions are to return the \color macro to the non-standard version-2 behavior, and to modify the \require macro to convert the version-2 TeX extension names into the corresponding version-3 names.

In addition, this example also defines versions of

• MathJax.Hub.Queue()
• MathJax.Hub.Typeset()
• MathJax.Callback()

that you may be able to use to keep custom code that uses these version 2 features working. It also defines

• MathJax.Hub.Register.StartupHook()
• MathJax.Hub.Register.MessageHook()
• MathJax.Hub.Config()

to generate error messages and looks for

<script type="text/x-mathjax-config">
...
</script>


blocks, which are no longer supported, in order to alert you to the need to convert these to version 3 by hand.

You should use the configuration converter to help convert your version 2 configuration to a comparable version 3 configuration.

Run the example