# HTML5

The html5 transformation generates HTML5 output and a table of contents (TOC) file.

The HTML5 output is always associated with the default DITA-OT CSS file (commonltr.css or commonrtl.css for right-to-left languages). You can use toolkit parameters to add a custom style sheet that overrides the default styles, or generate a `<nav>` element with a navigation TOC in topic pages.

To run the HTML5 transformation, set the transtype parameter to html5, or pass the --format=html5 option to the dita command line.

    dita --input=input-file --format=html5

where:

- input-file is the DITA map or DITA file that you want to process.