Yes, .docx is Microsoft Word's native file format, but the name can be confusing
.docx stands for "Office Open XML Document" and is the default format Microsoft Word has used since 2007. When you save a document in Word, it becomes a .docx file unless you choose a different format. However, .docx files can be opened and edited in many programs beyond Word — Google Docs, LibreOffice, Apple Pages, and dozens of others all read and write .docx.
The confusion happens because "Word document" can mean two things: a document created in Microsoft Word (the program), or a document saved in the .docx format (the file type). You can create a .docx file in Google Docs and it will still be a .docx file. You can open a .docx file in LibreOffice and edit it there. The format itself is separate from the program that created it.
From a privacy standpoint, the format matters less than where the file lives and what program opens it. A .docx file stored on your computer and opened in LibreOffice has different privacy implications than the same .docx file opened in Google Docs online. The file format is just the container; the real question is who can see what's inside.
Key Takeaways
- .docx is a file format that works in Word, Google Docs, LibreOffice, and many other programs — it is not locked to Microsoft Word alone.
- Microsoft Word online and desktop versions send data to Microsoft servers by default, while offline programs like LibreOffice keep your document on your device.
- A .docx file can contain hidden metadata — author names, edit history, comments — that travels with the file when you share it.
- Converting a .docx to .odt (LibreOffice's format) or .pdf does not change privacy, but switching from an online editor to an offline one does.
What metadata travels inside a .docx file
Every .docx file carries information about itself that you may not see when you open it. This metadata includes the author name, the date created, the date last modified, and sometimes a list of everyone who has edited the document. If you have tracked changes turned on, the file also stores who made each edit and when.
When you share a .docx file with someone else — by email, cloud storage, or file transfer — all of this metadata goes with it. A colleague who opens your document can see your name, your company, and the full edit history unless you strip it out first. Microsoft Word has a built-in tool to remove metadata: go to File > Info > Inspect Document > Inspect, then remove "Document Properties and Personal Information." LibreOffice has a similar feature under File > Properties > Security.
This matters most when you are sharing documents outside your organization or when you are concerned about who knows you worked on something. A resume sent as a .docx might reveal how many times you edited it. A contract might show which version you started from. The format itself does not cause this — .odt files and .pdf files can also carry metadata — but .docx is common enough that it is worth knowing how to clean it.
Microsoft Word online versus offline and what data goes where
Microsoft Word comes in two versions: the desktop program you install on your computer, and Word Online, which runs in your web browser. Both save files as .docx by default, but they handle your data very differently.
Word Online stores your documents on Microsoft's servers (OneDrive) and sends every keystroke, every edit, and every document you open to Microsoft. Microsoft's privacy policy states they use this data for product improvement, which means your writing is analyzed by their systems. You cannot use Word Online without a Microsoft account, and you cannot prevent data transmission — it is built into how the service works.
Word Desktop (the program you install) can save files locally to your computer, meaning the document never has to leave your device. However, Word Desktop still connects to Microsoft servers for features like spell-check, grammar suggestions, and cloud sync if you enable it. If you turn off all cloud features and save only to your local hard drive, your documents stay on your computer. If you use OneDrive sync, your documents go to Microsoft's servers just like Word Online.
The .docx format itself does not determine where your data goes — the program and your settings do. You can save a .docx file in LibreOffice and keep it entirely offline. You can save the same .docx in Word Online and have it transmitted to Microsoft servers constantly.
Why .docx is not the same as .doc, and when it matters
.doc is Microsoft Word's older format, used until 2007. .docx is the newer format that replaced it. The difference is technical: .docx is actually a compressed folder of XML files, while .doc is a proprietary binary format. For most people, the distinction does not matter — both formats work in modern programs, and both can carry metadata.
The only time this distinction matters for privacy is if you are working with very old documents or systems that do not support .docx. If someone sends you a .doc file and you open it in a modern program, it will work fine. If you need to send a document to someone using very old software, you might need to save it as .doc instead of .docx. Neither format is more or less private than the other.
Converting .docx to other formats and what changes
You can convert a .docx file to .pdf, .odt, .txt, or dozens of other formats. The conversion itself does not improve privacy — a .pdf file can also contain metadata, and a .txt file loses all formatting but keeps the text content. What matters is what you do with the file after conversion.
Converting to .pdf is useful when you want to prevent someone from editing your document or when you need a format that looks the same on every device. Most .pdf readers do not show metadata the way Word does, but the metadata is still there. If privacy is your concern, strip metadata from the .docx before converting, not after.
Converting to .odt (LibreOffice's native format) does not change privacy — it is just a different container for the same content. The real privacy gain comes from using LibreOffice itself, which keeps files on your computer by default instead of sending them to a company's servers.
When to use .docx, .odt, or .pdf based on your privacy comfort level
If you are working in Google Docs, Microsoft Word Online, or any cloud editor, the file format matters less than the fact that your document is on someone else's servers. The privacy trade-off is already made — you are using a service that reads your documents. In that case, .docx, .odt, or any other format will have the same privacy implications.
If you are using an offline program like LibreOffice or Apple Pages, stick with the format that program uses natively (.odt for LibreOffice, .pages for Pages). Saving in .docx works fine, but you lose some formatting and features specific to the program. More importantly, you may be tempted to sync the file to a cloud service later, which defeats the privacy benefit of working offline.
If you are sharing a document with someone outside your organization, convert to .pdf if you do not want them to edit it, or strip metadata from the .docx before sending it. Use File > Info > Inspect Document in Word or File > Properties > Security in LibreOffice to remove author names, edit history, and timestamps.
Frequently Asked Questions
Can someone tell if I edited a .docx file in a different program?
Not from the file format itself. However, if you edit a .docx in LibreOffice and then open it in Word, Word may show a notification that the file was edited in another program. The metadata will show the date and time of the edit, but not which program made it. If you want to hide the edit history entirely, use the metadata removal tool in your program before sharing.
Does saving a .docx file locally instead of in the cloud make it more private?
Yes, but only if you use a program that does not sync to the cloud. LibreOffice and Apple Pages can save .docx files locally without sending them anywhere. Microsoft Word Desktop can do the same if you turn off OneDrive sync. Google Docs always sends your document to Google's servers, regardless of the format you save it in.
What happens to metadata if I open a .docx in Google Docs?
Google Docs preserves most metadata but does not display it the way Word does. The author name, creation date, and edit history are stored in Google's system, and Google can see them. If you are concerned about metadata, strip it in Word or LibreOffice before uploading to Google Docs.
Is .docx less find than other formats?
.docx files can contain macros (small programs) that run when you open the file, which is a security risk if the file comes from an untrusted source. Other formats like .pdf and .txt cannot run macros. If you receive a .docx file from someone you do not know, open it in a program that disables macros by default, or convert it to .pdf first.
Can I use .docx files if I want to avoid Microsoft entirely?
Yes. LibreOffice, Google Docs, Apple Pages, and many other programs read and write .docx files without sending data to Microsoft. The format is open and standardized. If you use LibreOffice to open and edit .docx files and save them locally, Microsoft never sees your documents.