How to Save a Word Document as a DOCX File
If you've been working in Microsoft Word and need to make sure your file is saved in the modern .docx format — or you've inherited an older .doc file and need to convert it — the process is straightforward. But understanding why the format matters, and what can change depending on your setup, is just as useful as knowing the steps.
What Is DOCX and Why Does It Matter?
.docx is the default file format for Microsoft Word documents created since Word 2007. It replaced the older .doc format, which dates back to Word 97–2003. The difference isn't just cosmetic.
DOCX is based on Open XML — an open, standardized file structure that stores your document's content, formatting, and metadata in a compressed package. This makes files generally smaller, more recoverable if corrupted, and more compatible with third-party apps like Google Docs, LibreOffice, and Apple Pages.
.doc is a proprietary binary format. It's still widely readable, but it carries more compatibility risk when shared across different software versions or platforms.
If someone asks you to send a "Word document," they almost always mean a .docx file.
How to Save a Word Document as DOCX (Windows and Mac)
In Microsoft Word (Any Recent Version)
- Open your document in Word.
- Click File in the top menu.
- Select Save As (or Save a Copy in Microsoft 365).
- Choose your save location (your computer, OneDrive, etc.).
- In the file format dropdown (labeled "Save as type" on Windows or "File Format" on Mac), select Word Document (.docx).
- Click Save.
That's it. Your file is now saved as a .docx.
💡 If you opened an older .doc file, Word may display a Compatibility Mode label in the title bar. Running Save As and selecting .docx removes compatibility mode and fully upgrades the file.
Using "Convert" for Older Files
If you opened a .doc file and want to upgrade it in place:
- Go to File → Info.
- Look for the Convert button (visible when compatibility mode is active).
- Click it, then save.
This method updates the document to the modern format without prompting you to rename or relocate the file.
How to Save as DOCX on Different Platforms
The steps above cover desktop Word, but the format option behaves slightly differently depending on where you're working.
| Platform | How to Access Format Options |
|---|---|
| Word for Windows | File → Save As → "Save as type" dropdown |
| Word for Mac | File → Save As → "File Format" dropdown |
| Microsoft 365 (browser) | File → Save As → Download a Copy → choose .docx |
| Google Docs | File → Download → Microsoft Word (.docx) |
| LibreOffice Writer | File → Save As → choose .docx from format list |
| Apple Pages | File → Export To → Word → choose .docx |
Each of these produces a .docx file, but the fidelity of the output can vary — particularly when converting from Google Docs or Pages, where complex formatting, embedded objects, or custom styles may not translate perfectly.
What Can Change Between Platforms
Formatting Behavior
When you save a Google Doc as .docx and open it in Word, most basic formatting carries over cleanly. But tables, headers, custom fonts, and text boxes can shift. The more complex the document, the higher the chance of minor layout changes.
Compatibility Mode
Older versions of Word (2003 and earlier) can't open .docx files natively without a compatibility pack. If you're sharing with someone on legacy software, you may need to save as .doc instead — though this is increasingly rare.
File Size
DOCX files are typically smaller than equivalent .doc files due to the compressed XML structure. For most users this is a non-issue, but it matters if you're managing large archives or have email attachment size limits.
Macros and Legacy Features
Some features from the .doc era — particularly macros written in older VBA formats — may behave differently after conversion. Word usually flags these during the save process.
Checking the File Format After Saving
Not sure if your file actually saved as .docx? A few quick ways to check:
- File name extension: If your operating system shows file extensions, the file should end in .docx, not .doc.
- Title bar in Word: If it no longer shows "Compatibility Mode" after saving, you're in .docx.
- File properties: Right-click the file → Properties (Windows) or Get Info (Mac) → check the file type listed.
🗂 When the Format Choice Is More Complicated
For most everyday users — writing reports, resumes, letters, or shared drafts — saving as .docx is the right default. But the format choice gets more nuanced depending on a few variables:
- Who you're sharing with: If the recipient uses Word 2003 or older, .docx won't open without extra software.
- What software created the original file: Files from Google Docs, Pages, or LibreOffice converted to .docx may need a formatting review before sharing professionally.
- Whether the document contains macros or automation: These deserve extra attention during any format conversion.
- Whether you need the file to be non-editable: In that case, .docx isn't the right format at all — PDF would be.
The mechanics of saving as .docx are simple. What actually determines the right approach is how the document was built, where it's going, and what happens to it once it gets there.