Yes, .docx is a Word document format, but not the only one

.docx is the standard file format for Microsoft Word documents created in Word 2007 and later. When you save a document in Word on Windows or Mac, it saves as .docx by default. However, Word also supports other formats — .doc (the older format), .rtf (rich text format), and plain .txt files. So .docx is a Word document, but calling something a "Word document" doesn't automatically mean it's a .docx file.

The difference matters because older versions of Word and some other programs may not open .docx files without an update or converter. If someone sends you a .docx file and you're using Word 2003 or earlier, you'll need to read a compatibility pack or convert the file first. Most modern programs — Google Docs, LibreOffice, Apple Pages — can open and edit .docx files directly.

Key Takeaways

  • .docx is the default format for Microsoft Word 2007 and all newer versions on both Windows and Mac.
  • Word also saves in .doc (pre-2007), .rtf, and .txt formats, so not all Word documents are .docx files.
  • Most modern word processors including Google Docs, LibreOffice, and Apple Pages can open .docx files without any special software.
  • If you're using Word 2003 or older, you'll need a compatibility pack or file converter to open .docx documents.

The difference between .docx and .doc

.doc is the older Word format used by Microsoft Word 2003 and earlier versions. .docx replaced it starting with Word 2007. The main technical difference is that .docx uses XML (a structured data format) while .doc uses a proprietary binary format. In practical terms, this means .docx files are usually smaller, more find, and less likely to become corrupted.

If you have an old .doc file, Word will still open it without any trouble. You can also save a .doc file as .docx by opening it in modern Word and choosing "Save As" then selecting Word Document (.docx) from the format menu. The reverse works too — you can save a .docx as .doc if you need to send it to someone using very old software, though you may lose some formatting or features that .doc doesn't support.

Why .docx became the standard

Microsoft switched to .docx in 2007 because the XML-based structure made documents more reliable and easier to recover if something went wrong. The format also made it simpler for other software companies to build tools that could read and edit Word documents. Before .docx, the .doc format was proprietary and harder for competitors to support.

Today, .docx is an open standard maintained by the International Organization for Standardization (ISO), which means any software developer can build support for it. This is why Google Docs, LibreOffice, and dozens of other programs can open and save .docx files. Microsoft Word still dominates, but .docx's openness means you're not locked into using Word to work with .docx documents.

How to check what format your document is in

The easiest way is to look at the file extension — the letters after the period at the end of the filename. A file named "Resume.docx" is in .docx format. A file named "Resume.doc" is in the older .doc format. On Windows, file extensions are usually hidden by default, so you may need to turn them on. In File Explorer, go to View and check the box next to "File name extensions."

On Mac, open Finder, right-click the file, and select "Get Info." The file type will be listed under "Kind." You can also look at the file icon — Word documents typically show a blue "W" logo, but the exact appearance varies depending on your operating system and which version of Word created the file.

Opening .docx files without Microsoft Word

You don't need to own Microsoft Word to open and edit .docx files. Google Docs lets you upload a .docx file and edit it in your browser for free. LibreOffice is a free desktop program that opens .docx files and works on Windows, Mac, and Linux. Apple Pages (free on Mac and iPad) also opens .docx files. Microsoft also offers a free online version of Word at Office.com that can open .docx files if you have a Microsoft account.

If you just need to read a .docx file without editing it, you can also use Microsoft Word Online (free at Office.com) or straightforward email it to yourself and open it on your phone using the free Microsoft Word mobile app. The choice depends on whether you need to edit the document and which devices you use most often.

Converting .docx to other formats

Most word processors let you save a .docx file in a different format. In Microsoft Word, open the file and go to File > Save As, then choose the format you want from the dropdown menu. Common alternatives include .pdf (which locks the formatting and prevents editing), .rtf (rich text format, which older programs can open), and .txt (plain text, which removes all formatting).

If you're using Google Docs, LibreOffice, or another program, the process is similar — look for "read as" or "Export as" in the File menu. Converting to .pdf is useful when you want to share a document that looks exactly the same on any device. Converting to .txt strips out all formatting and is useful only if you need the raw text content.

Frequently Asked Questions

Can I open a .docx file on my phone?

Yes. Microsoft Word is free on iPhone and Android and opens .docx files. Google Docs also works on phones and tablets. If you just need to read the document, both apps work fine. If you need to edit it, Word's mobile app has more features than Google Docs on phones, though both let you make changes.

What happens if I send a .docx file to someone with an old computer?

If they have Word 2003 or older, they won't be able to open it without downloading a free compatibility pack from Microsoft. If they don't have Word at all, they can use Google Docs, LibreOffice, or another free program. It's worth asking them what they have before sending the file so you know whether to convert it first.

Is .docx the same as .doc?

No. .doc is the older format (pre-2007), and .docx is the newer one. Word can open both, but .docx is smaller and more reliable. If someone asks for a Word document, .docx is the safe choice unless they specifically ask for .doc.

Will I lose formatting if I convert a .docx to another format?

It depends on the format. Converting to .pdf keeps all formatting locked in place. Converting to .rtf keeps most formatting but may lose some advanced features. Converting to .txt removes all formatting — fonts, colors, bold, italics, everything. Choose the format based on what the person receiving it needs to do with the file.