What Is a DOCX File? A Simple Guide
You’ve probably seen a file that ends in .docx. Maybe it came in an email, or you downloaded it from a website. But what is it, and how do you open it if you don’t have Microsoft Word?
This guide explains what a DOCX file is in plain words. You’ll learn where it came from, what’s inside it, and the easiest free ways to open one on any device.
A DOCX file is a Word document
A DOCX file is a text document made in Microsoft Word, or in an app that can save in Word’s format. It’s the standard file type for Word documents today.
A DOCX file can hold:
- Text with fonts, sizes and colours
- Headings, lists and tables
- Pictures and shapes
- Headers, footers and page numbers
- Footnotes, comments and tracked changes
In short, if you can make it in Word, it can live in a DOCX file.
What does DOCX stand for?
The “DOC” part means document. The “X” comes from XML, which is the code Word uses to store what’s inside the file. So DOCX simply means a Word document stored as XML.
You may also hear it called “Word docx”, “a Word file” or “a .docx”. They all mean the same thing.
A short history of DOCX
Before 2007, Word saved files in a format called DOC. DOC files were closed and hard for other programs to read.
In 2007, Microsoft released Word 2007 with a new format: DOCX. It was based on an open standard called Office Open XML. Because the standard is public, other companies could build apps that read and write DOCX files properly.
That’s why Google Docs, LibreOffice, Apple Pages and many other apps can open Word files today. If you want to compare the two formats, read our guide on DOCX vs DOC. If you have an old file, see how to open a DOC file.
Who uses DOCX files?
Almost everyone who writes on a computer. Here are some of the places you’ll meet them:
- Jobs: CVs, cover letters and job offers
- School: essays, homework and reading lists
- Business: contracts, reports, quotes and letters
- Government: forms and guidance you download and fill in
- Writers: book drafts sent to editors and publishers
DOCX is popular because it’s easy to edit and share. The person who gets your file can change it, add comments or track changes, then send it back.
What’s inside a DOCX file?
Here’s something surprising. A DOCX file is really a ZIP folder with a different name. Inside the folder are several smaller files:
| Part | What it holds |
|---|---|
| document.xml | The main text of your document |
| styles.xml | Fonts, heading styles and spacing |
| media folder | Pictures you added |
| header and footer files | What appears at the top and bottom of each page |
| settings files | Page size, margins and other settings |
Because everything is packed and compressed, DOCX files are much smaller than old DOC files. A long report with pictures can still be only a few hundred kilobytes.
This also explains a common problem. Sometimes a DOCX file opens as a ZIP folder by mistake. That’s not a virus. It just means your computer is using the wrong app for it.
How to tell if a file is a DOCX file
Look at the end of the file name. The last part after the dot is called the file extension. A DOCX file ends in .docx.
On Windows, file extensions are often hidden. To see them, open File Explorer, click View, then Show, and tick File name extensions. On a Mac, select the file in Finder and choose File, then Get Info. The full name, with the extension, appears under Name and Extension.
You’ll also spot a Word icon next to the file if Word or another word app is installed. But icons can change from one computer to another, so the extension is the safer check.
How to open a DOCX file
You don’t need to buy Microsoft Word to open a DOCX file. Here are the easiest free ways.
1. Open it online in your browser
The quickest way is our free online DOCX viewer. Drop your file in the box and it opens right away. It works on phones and computers, and your file never leaves your device. You can zoom, copy the text, print it or save it as a PDF.
2. Use Google Docs
Upload the file to Google Drive and open it with Google Docs. It’s free and lets you edit the file. Our guide on opening DOCX files in Google Docs shows every step.
3. Use Word for the web
Microsoft offers a free online version of Word. You need a Microsoft account, and your file goes to OneDrive. Read how in our guide to opening DOCX files in Word online.
4. Use a free desktop app
LibreOffice Writer is free for Windows, Mac and Linux. Apple Pages is free on Mac, iPhone and iPad. Both open and edit DOCX files.
For a full list of options, see how to open a DOCX file without Microsoft Word or our roundup of the best free DOCX viewers.
How to open a DOCX file on your device
Each device has its own easy way in. Pick yours:
- Open a DOCX file on Windows 11
- Open a DOCX file on Mac
- Open a DOCX file on iPhone
- Open a DOCX file on Android
How to make a DOCX file
Want to create one yourself? Any of these free apps can save a DOCX file:
- Google Docs: write your document, then go to File, Download, Microsoft Word (.docx).
- LibreOffice Writer: choose File, Save As, and pick the Word 2007-365 format.
- Apple Pages: choose File, Export To, Word.
- Microsoft Word: DOCX is the default, so a normal save is enough.
DOCX vs other file types
DOCX isn’t the only document format. Here’s how it compares to the ones you’ll see most often.
| Format | Best for | Easy to edit? |
|---|---|---|
| DOCX | Documents you or others will change | Yes |
| DOC | Old Word files from before 2007 | Yes, but older |
| Final documents that must look the same everywhere | Not really | |
| TXT | Plain text with no formatting | Yes, but no styles |
| ODT | Documents made in LibreOffice | Yes |
A good rule: send a DOCX file when the other person needs to edit it. Send a PDF when they only need to read or print it. Our guide on converting DOCX to PDF shows how.
Are DOCX files safe?
A normal DOCX file can’t hold macros. Macros are small programs that some harmful files use. That makes DOCX safer than the old DOC format or the macro-enabled DOCM format.
Still, be careful with files you didn’t expect. Don’t click Enable Content on a file from a stranger. And if you’re unsure, opening the file in a viewer that only shows content is a safer first step.
Common DOCX problems
Most DOCX files open without trouble. When they don’t, it’s usually one of these:
- The file name is odd. Downloads sometimes end up named file.docx(1) or file_docx. Our guide on fixing strange DOCX file names shows how to rename them.
- The download didn’t finish. Download the file again.
- The file has a password. You’ll need the password to open it.
- The file is damaged. Ask the sender for a new copy.
For step-by-step help, read why won’t my DOCX file open.
DOCX files and accessibility
DOCX files can be made easy to read for everyone, including people who use screen readers. Using real headings, adding alt text to pictures and keeping tables simple all help. Word has a built-in Check Accessibility tool on the Review tab that points out problems. A well-built DOCX file also turns into a better PDF.
Frequently asked questions
Is DOCX the same as Word?
DOCX is the file format. Word is the program. Word saves files as DOCX, but many other programs can open and save DOCX too.
Can I open a DOCX file without Word?
Yes. You can use our online DOCX viewer, Google Docs, Word for the web, LibreOffice or Apple Pages. All are free.
Can I open a DOCX file on my phone?
Yes. Phones can open DOCX files in a browser, in Google Docs, in Pages or in the free Word app.
Why is my DOCX file so small?
DOCX files are compressed like a ZIP file. That keeps them small, even with pictures inside.
What program made my DOCX file?
Often Microsoft Word, but not always. Google Docs, LibreOffice, Pages and many online tools can all save DOCX files. The format is the same no matter which app created it.
Can a DOCX file have a virus?
A normal DOCX file can’t run macros, so the risk is low. Harmful files usually try to trick you into enabling macros or clicking a link inside. Be careful with files from strangers.