The .docx format is just a zip file containing multiple .xml files (and sometimes other types) that constitute a given file.

The document content structure is standardized on Office Open XML (https://en.wikipedia.org/wiki/Office_Open_XML).

To explore a .docx file you can unzip it into a folder ie: unzip -d unzipped-folder my_docx.docx

Key files:

• document.xml: Contains the main document data. This is usually your starting point.
• styles.xml: Contains style definitions, often will be referenced from document.xml
• theme/theme1.xml: Contains theme level definitions

Super Editor imports/exports to/from .docx using SuperConverter For import, see docxImporter.js For export, see exporter.js