64. XHTML

To convert AsciiDoc to XHTML, set the backend to xhtml5.

Produce XHTML using the built-in HTML converter
asciidoctor -b xhtml5 document.adoc

To produce XHTML instead of HTML when using converter templates, set the htmlsyntax attribute to xml in addition to the backend option:

Produce XHTML using custom templates
asciidoctor -T /path/to/templates -b slides -a htmlsyntax=xml document.adoc
Black Box Decoded: XHTML and htmlsyntax

XHTML output is a special mode of the built-in HTML5 converter. It is activated by prefixing the backend value with x (e.g., xhtml or xhtml5). This hint implicitly assigns the htmlsyntax attribute to the value xml, which normally has the value html.

For all other converters, the htmlsyntax attribute is not set explicitly. If you want a converter template that’s written in Slim or Haml to output XHTML instead of the default HTML, you simply need to set the htmlsyntax attribute to xml explicitly. Asciidoctor will pass on this preference to the Slim or Haml template engine by setting the :format option to :html5.