Formats

What is a DOCX File and Why is it the Standard?

By Covertfily Team • April 9, 2026

If you've ever used Microsoft Word or received a document in an email, you've likely encountered the .docx extension. But what exactly is it, and how does it differ from the older .doc format?

The Evolution of Documents: From .DOC to .DOCX

Before 2007, Microsoft Word used the .doc format, which was a binary format. In 2007, Microsoft introduced Office Open XML, which gave birth to the .docx format. The 'X' at the end stands for XML (Extensible Markup Language).

Why .DOCX is Better

How to Open a DOCX File

You can open DOCX files with almost any modern word processor, including Microsoft Word, Apple Pages, and Google Docs. However, if you need to convert it to another format—like PDF or HTML—for better sharing, a dedicated converter is your best bet.

The Covertfily Advantage

Most online converters send your DOCX files to a remote server. At Covertfily, we believe your documents should stay private. Our engine converts DOCX files 100% locally in your browser using the MIT-Licensed power of your own hardware.

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