Doc vs docx comes down to age: .doc is the old Word 97–2003 format and .docx is the modern one Word has used since 2007. Save new work as .docx unless someone with very old software needs the file, and when you send a document that must not change, save it as a PDF instead.
In this guide, you’ll learn what .doc, .docx, .docm and .dotx files are, how they differ in size and safety, which one to pick, and how to convert an old file. Everything here applies to Word for Windows in Microsoft 365, Word 2021, 2019 and 2016.
Doc vs Docx vs Docm vs Dotx at a Glance
| Extension | What it is | Holds macros? | Use it for |
|---|---|---|---|
| .docx | Word Document (since Word 2007) | No | Almost everything you write |
| .doc | Word 97–2003 Document | Yes | Only people using Word 2003 or older |
| .docm | Word Macro-Enabled Document | Yes | Documents that run your own macros |
| .dotx | Word Template | No | A starting point you reuse, such as a letterhead |
👉 There is a fifth, rarer one: .dotm, a template that can hold macros. Word’s own Normal.dotm is one.
What Is a .docx File?
A .docx file is the standard Word document. Inside, it is a zip folder of XML files, which makes it small, harder to corrupt and readable by Google Docs, LibreOffice, Pages and Word on any device. It cannot store macros, so a .docx from someone else cannot run hidden code.
👉 Doc vs docx in numbers: in our test, the same 20 paragraphs saved as .docx came to 14 KB; as .doc they took 62 KB, more than four times the space.
What Is a .doc File?
A .doc file uses the older binary format from Word 97 to Word 2003. Current Word opens it in Compatibility Mode — you will see the words next to the file name — and turns off newer features so the file still works in old versions.
Steps to convert a .doc file to .docx:
- Open the .doc file in Word.
- Click File > Info.
- Click Convert, then OK.
- Save the file. Word saves a new .docx copy and leaves the old .doc alone.
👉 Converting can move a few things slightly, such as tables and text boxes, so check long documents page by page afterwards.
What Is a .docm File?
A .docm file is a .docx that is allowed to carry macros — small programs written in VBA that automate tasks. If you add a macro and try to save as .docx, Word warns that the macro will be removed and offers .docm instead. You record and edit macros from the Developer tab.
👉 Treat a .docm from someone you do not know with care. Windows and Word block macros in files downloaded from the internet, and you should only unblock them when you trust the sender.
What Is a .dotx File?
A .dotx file is a template: a starting point you reuse. When you double-click a template, Word does not open the template itself — it opens a new, untitled document based on it, so the original stays clean. That makes .dotx ideal for letterheads, invoices and forms you fill in again and again.
Steps to save a document as a template:
- Set up the document the way you want every copy to start.
- Click File > Save As > Browse.
- In Save as type, choose Word Template (*.dotx).
- Name it and click Save.
👉 To edit the template itself later, right-click the .dotx file in File Explorer and choose Open, not New.
Doc vs Docx: Which Word File Type Should You Use?
- Writing, sharing or submitting a document? Use .docx.
- Sending to someone on Word 2003 or older? Save a copy as .doc.
- The document runs your own macros? Use .docm.
- A layout you will reuse many times? Use .dotx.
- Nobody should edit it? Send a PDF — or make the document read only.
How to See File Extensions in Windows
Windows hides extensions by default, so every file just looks like “Report”. To see them in Windows 11, open File Explorer, click View > Show and tick File name extensions.
Common Problems with Word File Types
- “Compatibility Mode” after the file name: the file is a .doc. Convert it from File > Info.
- “The following cannot be saved in a macro-free document”: the file has macros. Save as .docm to keep them, or carry on as .docx to remove them.
- A template keeps opening as “Document1”: that is how templates work. Right-click the .dotx and choose Open to edit the template.
- A file will not open at all: see how to recover a corrupted document in Word.
FAQs
Is docx better than doc?
Yes, for almost everything. A .docx file is smaller, safer and supports every current Word feature. Use .doc only for people on Word 2003 or older.
Can Word still open .doc files?
Yes. Word opens them in Compatibility Mode. Use File > Info > Convert to turn them into .docx.
What is the difference between docx and docm?
A .docm file can contain macros; a .docx cannot. Otherwise they are the same format.
What is a dotx file?
A Word template. Opening it creates a new document based on it, so the template itself never changes.
Can Google Docs open a docx file?
Yes — see how to open a Word document in Google Docs.
Why is my .doc file so much bigger than the .docx?
The .doc format is not compressed. In our test the same text was 62 KB as .doc and 14 KB as .docx.
Conclusion
Doc vs docx is an easy choice: .docx for everyday work, .doc only for very old software, .docm when you need macros and .dotx for anything you reuse.
Convert old files when you open them, keep templates as .dotx, and when a file must reach someone exactly as you made it, save a Word document as a PDF.
Related Tutorials
- How to Save a Word Document as a PDF
- How to Convert a PDF to Word Document
- How to Recover a Corrupted Document in Word
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For Microsoft support documentation, visit the official Microsoft guidance.
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