.docx
what is a docx file?
The docx file extension is an open XML document primarily used by Microsoft Word. docx files can contain multiple pages, text, images, and other formatted content.
download docx sample file

ffc.docx example file is licensed CC0, Public Domain Dedication
docx file extensions
.docx
docx file extension name
Open XML Microsoft document
docx file type
primary: Document
secondary: text, Microsoft
docx file structure
docx files generally contain one or more pages of formatted text. docx files can also contain images and other content embedded in the document.
associated organization
Microsoft
docx format specification and identification
docx files are actually zip files in disguise. Replacing the .docx extension with .zip on the sample ffc.docx file reveals the following structure:
docx MIME type
application/vnd.openxmlformats-officedocument.wordprocessingml.document
docx file signature hex
50 4B 03 04
docx ISO 8859-1
PK..
docx offset
0
docx magic number
50 4B 03 04 [PK]
docx file character encoding / charset
binary