What Is a DOCX File? How to Open, Edit and Convert It

A DOCX file is a word-processing document saved in Microsoft’s modern Word format. It is the file you get when you create a letter, report or CV in recent versions of Microsoft Word, and the extension you will see at the end of the file name is .docx. Even though the format was built by Microsoft, you do not need Microsoft Word to use it: free tools such as Google Docs, LibreOffice and Apache OpenOffice can open DOCX files too. This guide explains what a DOCX file actually is, what is hidden inside it, and exactly how to open, edit and convert one — including the free options that matter most in New Zealand.

What is a DOCX file in plain English?

A DOCX file is a text document that stores your words along with all of their formatting — fonts, headings, colours, tables, images, page layout and more. The “X” in the name signals that it is built on XML (Extensible Markup Language), a plain-text way of labelling and structuring data that most modern software can read.

DOCX became the default save format in Microsoft Word 2007 and has been the standard Word format ever since. When someone emails you “a Word document” today, it is almost always a .docx file. It is used for virtually every kind of everyday document: job applications, invoices, essays, business proposals, meeting notes and contracts.

How is DOCX different from the old DOC format?

DOCX replaced the older DOC format, and the change was much bigger than adding one letter. The legacy .doc format was a single binary file — a block of computer code that only Microsoft Word could reliably understand. DOCX takes a completely different approach: it is really a small ZIP archive (a compressed folder) that holds a set of readable XML files bundled together.

That shift brought real, practical benefits:

• Smaller files. Because the contents are compressed, a DOCX is usually smaller than the equivalent old DOC file.
• Better recovery. If part of the file is damaged, the rest can often still be read, because the content is split across several internal parts rather than locked in one binary block.
• Open and documented. The format is published as a public standard, so many different programs can read and write it rather than just Word.
• Safer by default. A plain .docx cannot contain the automated macros that older documents could hide (more on that below).

What is actually inside a DOCX file?

Inside, a DOCX file is a structured package of parts, not a single document. Because it is a ZIP archive, you can see this for yourself: make a copy of a .docx file, rename the copy so it ends in .zip, and open it like any other zipped folder. You will find a small tree of files and folders, including:

• [Content_Types].xml — a required index that tells software what kind of content each part holds.
• word/document.xml — the main part, containing the actual text and structure of your document.
• _rels — a “relationships” folder that links the parts together so they load in the right order.
• docProps — document properties such as the author name, title, word count and a thumbnail preview.
• A media folder (when images are present) holding each picture as its own file.

This arrangement is formally called the Open Packaging Conventions (OPC). For everyday use you never need to open the ZIP — your word processor hides all of it — but knowing the file is really a tidy bundle of parts explains why DOCX is so portable and so widely supported.

Who created DOCX, and is it an official standard?

Microsoft created the DOCX format, but it is also an internationally recognised standard rather than a private, locked format. DOCX is one part of a wider family called Office Open XML (OOXML), which also includes XLSX for spreadsheets and PPTX for presentations.

The format was standardised in two steps. It was first approved by the standards body Ecma International as ECMA-376 in December 2006, and then published by the ISO/IEC joint committee as ISO/IEC 29500 in November 2008. Because the specification is public, developers of other office suites — including the free ones — can legally build in support for reading and writing DOCX. That is the reason a document created in Word can be opened in Google Docs or OpenOffice Writer without any special plugin.

How do you open a DOCX file?

You can open a DOCX file in several free and paid programs, on any device. The right choice depends on what you already have installed and whether you need to keep the formatting exactly as the sender intended.

Microsoft Word

Word is the native home of the DOCX format, so it opens and displays these files most faithfully, including complex layouts, tracked changes and comments. Word is part of a paid Microsoft 365 subscription or the one-off Office purchase, but there is also a free Word for the web that runs in your browser and opens DOCX files without any installation.

Google Docs

Google Docs opens and edits DOCX files for free, which makes it a popular choice when you do not have Word. Upload the file to Google Drive, right-click it, and choose Open with > Google Docs. You can keep working in DOCX or convert the file to Google’s own format. Very heavy Word formatting can shift slightly, so always check the layout after opening.

LibreOffice and Apache OpenOffice

Both of these free, open-source suites open DOCX files on Windows, Mac and Linux. LibreOffice Writer and OpenOffice Writer read DOCX well, and LibreOffice can also save back to DOCX, which is useful when you need to return an edited file in the same format. If you are deciding between the two suites, our comparison of Apache OpenOffice’s features and current status is a good starting point.

Phones, tablets and the web

On a phone or tablet you can open DOCX files with the free Microsoft Word or Google Docs mobile apps, or Apple Pages on an iPhone or iPad. Many email apps and cloud services (Gmail, Outlook, Dropbox) also show a quick preview of a DOCX attachment so you can read it without opening a full editor.

How do you edit a DOCX file?

To edit a DOCX file, open it in any word processor that supports writing to the format, make your changes, and save. The key point is that not every program can save back to DOCX, even if it can open one — so check before you start a long edit.

• Microsoft Word and Word for the web edit and save DOCX natively.
• LibreOffice Writer edits and can save directly as .docx (choose it in the Save As dialog).
• Google Docs edits DOCX and can download the result as .docx again (File > Download > Microsoft Word).
• Apache OpenOffice Writer opens and edits DOCX content, but cannot save in the DOCX format — this is an important limitation covered in the next section.

If you only need to read a document and not change it, you do not have to edit it at all — a preview or a PDF copy is often enough.

Why can’t Apache OpenOffice save in DOCX?

Apache OpenOffice can open and read DOCX files but has never been able to save documents in the DOCX format, and that remains true in the current 4.1.16 release. OpenOffice uses the OpenDocument Format (ODT) as its native format and can export to older formats such as .doc, .rtf, .txt and .pdf — but “.docx” is not on its save list.

If you are an OpenOffice user who must return a file as a .docx, you have two straightforward options:

• Use LibreOffice instead for that document. LibreOffice is the sister project of OpenOffice and saves DOCX directly. You can compare the download and install options for both free suites before you choose.
• Save as ODT, then convert. Save your work in OpenOffice as .odt, then open that file in LibreOffice or Google Docs and save it as .docx. To understand the format you would be saving instead, see our guide to ODT files and how they compare with DOCX.

How do you convert a DOCX file?

Converting a DOCX file means saving it as a different format, and the method depends on what you are converting to. The safest conversions are done inside a desktop program rather than on random websites, because a document can contain private information.

DOCX to PDF

Open the file in Word, LibreOffice, OpenOffice or Google Docs and use Export as PDF or Print to PDF. A PDF locks the layout so it looks the same on every device, which makes it the best format for sending a finished document that should not be changed.

DOCX to ODT or DOC

Use Save As (or File > Download in Google Docs) and pick the target format from the list. LibreOffice and OpenOffice both handle DOCX-to-ODT cleanly; Word and LibreOffice can save back to the old .doc if you need to support very old software.

DOCX to Google Docs format

Open the DOCX in Google Docs, then choose File > Save as Google Docs. This creates a separate Google Docs copy and leaves your original .docx untouched.

PDF back to an editable Word file

Going the other way — turning a PDF into an editable DOCX — is also possible. Our guide on how to open a PDF in Word explains what formatting survives and where scanned documents cause trouble.

DOCX and macros: what is a DOCM file?

A normal DOCX file cannot run macros, which is good news for security. A macro is a small automated script stored inside a document; macros can be genuinely useful, but they have also been a common way to hide malware. To keep the ordinary format safe, Microsoft split macros into a separate extension: .docm. If a document needs to carry macro code, it must be saved as .docm, and your software will usually warn you before running anything.

The practical takeaway is simple: a plain .docx is a document, not a program. If you unexpectedly receive a .docm file, or a .docx that asks to “enable macros”, treat it with caution, especially from an unknown sender.

Is a DOCX file safe to open, and what about privacy?

A DOCX file is generally safe to open, but two things are worth knowing. First, like any document type it can in rare cases be used to carry harmful content, so only open files from people you trust and keep your software up to date. Second, DOCX files quietly store metadata — hidden information such as the author’s name, the time spent editing, earlier comments and tracked changes.

Before you send a DOCX outside your organisation, it is worth checking that metadata. In Word you can use Inspect Document to remove personal details; in LibreOffice you can clear this under the file properties. For anyone handling client or personal information in New Zealand, this matters under the Privacy Act 2020, which expects reasonable care with personal data. When in doubt, send a PDF copy instead, as it carries less of this hidden history.

DOCX vs ODT and PDF: which should you use?

Choose the format that matches the job, not just the one your software opens by default. The three you will meet most often are DOCX, ODT and PDF, and each has a clear purpose:

• DOCX is best when the recipient uses Microsoft Word or needs to edit the document and send it back. It is the most widely expected editable format in business.
• ODT is the open standard used natively by LibreOffice and OpenOffice. It is ideal if you and your collaborators use those free suites, and it avoids depending on a single company’s format.
• PDF is best for a finished document that should look identical everywhere and not be edited — contracts, invoices sent to clients, or anything you are publishing.

A common workflow is to draft and edit in DOCX or ODT, then export a PDF as the final, shareable copy.

Common mistakes with DOCX files

Most DOCX problems come from a handful of avoidable mistakes. Watching for these saves a lot of frustration:

• Assuming formatting is identical everywhere. A document created in Word can shift slightly when opened in Google Docs or OpenOffice, especially with custom fonts, columns or complex tables. Always preview before printing or sending.
• Editing in OpenOffice and expecting a .docx back. OpenOffice cannot save DOCX, so you will get an ODT unless you convert the file in LibreOffice or Google Docs.
• Renaming a .doc to .docx (or the reverse). Changing the extension by hand does not convert the file and usually corrupts it. Use Save As inside a program instead.
• Uploading sensitive documents to unknown online converters. Free web converters may store your file on a server you do not control. Convert private documents on your own computer.
• Forgetting to strip metadata. Hidden comments, tracked changes and author details can travel with the file. Inspect and clean the document before sharing it externally.
• Sending DOCX when a PDF was needed. If the layout must stay fixed, a DOCX can be reflowed by the recipient’s software — send a PDF for anything final.

Who should use DOCX, and who might not?

DOCX suits almost anyone who writes documents that other people will edit. Students, office workers, job seekers and small businesses all benefit from using the format that the widest range of tools expects. If your workplace runs Microsoft Word or you regularly exchange editable files with others, DOCX is the sensible default.

You might lean towards ODT instead if you only use free open-source software and value an open standard, or towards PDF if you mainly send finished documents that should never change. The good news is that the free tools covered here let you move between all three formats, so you are never locked in.

Frequently Asked Questions (FAQ)

Is a DOCX file the same as a Word document?

In everyday terms, yes. DOCX is the modern Word document format that Microsoft Word has used by default since Word 2007. The older Word format used the .doc extension, so a very old Word document may be a .doc rather than a .docx, but both are “Word documents”.

Can I open a DOCX file without Microsoft Word?

Yes. You can open and read a DOCX file for free in Google Docs, LibreOffice Writer, Apache OpenOffice Writer, Apple Pages and the free Word for the web, among others. You only need paid Microsoft Word if you want the most exact rendering of very complex Word documents.

Why does my DOCX look different when I open it in another program?

Small differences happen because each program interprets the formatting in its own way, and some Word features or fonts are not supported identically everywhere. Simple documents usually look the same; heavily formatted ones with custom fonts, columns or complex tables are the most likely to shift.

How do I turn a DOCX into a PDF for free?

Open the DOCX in Word, Google Docs, LibreOffice or OpenOffice and choose the export or “print to PDF” option. All of these can produce a PDF at no cost, and the PDF will keep your layout fixed so it looks the same on any device.

Is it safe to open a DOCX file from someone I don’t know?

A plain DOCX is usually safe because it cannot run macros, but caution still pays off. Be wary of any document that asks you to “enable macros”, of files with the .docm extension, and of attachments from unknown senders. Keeping your software updated and your antivirus active reduces the risk further.