Explainer
What is a DOCX file? A plain-English explanation
The short answer
A DOCX file is a word-processor document saved in the Office Open XML format. Inside it is a zipped bundle of text and settings files, which is why many programs can open it. You can open one in Microsoft Word, LibreOffice, Google Docs, or in your browser with Wrdio.
You have seen the letters at the end of a file name: report.docx, cv.docx, notes.docx. They tell your computer which program should open the file. This guide explains what is behind those letters, in words that do not need a computer science degree.
The short story
Microsoft introduced the DOCX format with Office 2007. It replaced the older DOC format and became an open standard, which means anyone can build a program that reads it. That is why a file made in one program usually opens in another.
What is inside a DOCX file
A DOCX is really a small folder that has been zipped into one file. If you change the ending from .docx to .zip and open it, you will find folders and text files. The main ones are:
- document.xml, which holds your text and its structure.
- styles.xml, which holds the look of headings, body text and lists.
- A media folder, which holds pictures you inserted.
- Settings and properties, such as page size and the author name.
Because the pieces are separate, a program can read just the text, or just the pictures, without having to understand everything else. That also keeps files small.
Why a DOCX can look different in different programs
The file says what the document contains, not exactly how it must be drawn. Each program makes its own choices about spacing, fonts and line breaks. If your document uses a font that is not installed on the computer, a substitute is used and the text can reflow. Simple documents look almost the same everywhere. Complicated ones, with text boxes, columns or tracked changes, are where small differences appear.
If the exact look matters, send a PDF. We cover how in saving a Word document as a PDF without breaking it.
Which programs open DOCX files
| Program | Where it runs | Cost |
|---|---|---|
| Microsoft Word | Computer, phone, browser | Paid, with a limited free web version |
| LibreOffice Writer | Computer | Free |
| Google Docs | Browser, phone | Free with an account |
| Apple Pages | Mac, iPhone, iPad | Free on Apple devices |
| Wrdio | Browser | Free, no account |
DOCX, DOC, DOCM and DOTX
- .docx is a normal document.
- .doc is the older format. See DOCX vs DOC.
- .docm is a document that can contain macros, small programs that run inside it. Do not enable macros in files from people you do not know.
- .dotx is a template you start new documents from.
How to open one right now
The quickest way, with nothing to install, is to drop the file onto the Wrdio home page. It reads the file in your browser tab and does not upload it. If it will not open, read how to fix a DOCX that will not open.
Questions people ask
What does DOCX stand for?
DOCX is short for Document, with the X standing for XML, the markup language used inside the file. It is the format Microsoft Word has used since 2007.
Is a DOCX file the same as a DOC file?
No. DOC is the older format and DOCX is the newer one. DOCX files are smaller, less likely to be damaged and easier for other programs to read.
What program opens a DOCX file?
Microsoft Word, LibreOffice Writer, Google Docs, WPS Office, Apple Pages and browser tools such as Wrdio can all open DOCX files.
Can a DOCX file contain a virus?
A DOCX file cannot run macros. The related DOCM format can, so be careful with those. Any document can still link to harmful sites, so treat unknown files with care.