From .doc to .docx
The old .doc format was a single opaque binary blob, tied to Microsoft's software and hard for anyone else to parse. DOCX, introduced with Office 2007, replaced it with something open and inspectable: a ZIP archive of XML parts describing the text, styling and embedded media. Rename a .docx to .zip and you can browse the pieces.
That openness (standardised as ISO/IEC 29500) is why Google Docs, Apple Pages, LibreOffice and countless tools can all open and produce DOCX, not just Word.
DOCX as a working format
DOCX is for documents that are still being written and revised — its whole point is that the text, structure and formatting stay editable. When a document is finished and you want it to look the same everywhere and resist changes, you export it to PDF. The two formats are partners: author in DOCX, deliver in PDF.
Strengths
- Fully editable: styles, tables, images, tracked changes and comments.
- Open ISO standard, readable by Word, Google Docs, Pages and LibreOffice.
- Compact zipped-XML structure.
Limitations
- Layout can shift slightly between apps and versions.
- Not ideal as a final deliverable — use PDF for that.
When to use Word (DOCX)
Use DOCX while you're writing and revising a document. Export to PDF when it's final and needs a locked, portable layout.
Word (DOCX) FAQ
- What's the difference between DOC and DOCX?
- DOC is the old binary Word format; DOCX is the newer Office Open XML format (a zipped set of XML files), which is an open standard and far more widely compatible.
- Can I open DOCX without Microsoft Word?
- Yes. Google Docs, Apple Pages, LibreOffice and many other apps open and edit DOCX, because it's an open standard.
- How do I turn a DOCX into a PDF?
- Export or "Save as PDF" from your word processor, or convert it with Morphr in your browser — text and basic formatting carry across to a fixed-layout page.