File with .JSPX extension contains data in the form of a dynamic website code created using XML syntax and generated on server side with JSP function. File data is stored in text format. This type of file is similar to JSP file but uses XML syntax. This format utilizes syntax markers in form of <% ... %>, <%@ ... %> for expressions and <%= ... %> for Java code blocks. JSPX files are functionally similar to PHP or ASP files.

JSPX files can be opened and edited with basic text editor although a website creation software supporting utilities such as syntax highlighting and correction is the preferred option. JSPX based websites require web browser that offers support for Java Server Pages and Java Virtual Machine (JVM).