DOC vs DOCX: 4 Key Differences Between These File Formats

Fauzi Muda /

When it comes to documents and word processing, two of the most popular formats you ll come across are DOC vs DOCX. These are the two primary formats used by Microsoft Word, but you may encounter them when exporting documents in Google Docs and Open Office, as well.

In this article, we ll look at the main differences between these two formats so you can choose the best solution for your needs.

DOC vs DOCX: Side-by-Side Comparison

File Type Binary XML-based
Size Larger Smaller
Compatibility Almost all Word versions Word 2007 and beyond
Security Lower (can be used to hide malware) Higher (threats easier to spot)
Interoperability Limited Higher (due to XML)
Collaboration Features Limited Extensive

DOCX vs DOC: What s the Difference?

Two of the most common file formats are DOC and DOCX. Below, you ll learn about the key differences between the two.

1. Document Format and Structure

With a DOC file, your document is saved as a binary file. Meanwhile, a DOCX file is actually a zip file with all the XML files associated with the document.

DOC is a proprietary file format, which means it s restricted toMicrosoftWord and isn t universally compatible with other platforms. On the other hand, DOCX is based on the Office Open XML (OOXML) standard. This makes DOCX files more easily accessible and able to be opened and modified using several apps and platforms.

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DOC is used for word processing documents stored in Microsoft s proprietary Microsoft Word Binary File Format.


DOC files store their data in a more congested manner, with all related information on formatting stored in a binary format. This makes the files larger and less efficient.

DOCX files, which are based on XML and stored in a zipped format, help reduce the file size and improve content accessibility. Not only do they load faster, but this allows for better compatibility with other applications.

2. Document File Size and Storage

In general, DOCX files typically have a much smallerfile sizewhen compared to their DOC counterparts. This is because DOCX files use a more efficient compression algorithm, which leads to reduced file sizes without compromising on quality.

Having smaller document sizes makes it easier to send docs as attachments and better manage your storage space. Whether that s on your computer, anexternal hard drive, or usingcloud storage. This also makes it easier to upload documents to cloud storage, when you re collaborating with other team members.

Another key difference is the way these formats handle images. DOCX files are more efficient at storing images within your documents than DOC files. So, when you include graphics or photos in your Word document, DOCX files will consume less space and still maintain the quality of the images.

Finally, DOC files are binary files, which makes them more prone to data corruption and less accessible when viewed using third-party text editors. On the other hand, DOCX files are XML-based, so there s a more consistent and flexible file structure, that s less prone to errors and data corruption.

3. Overall Features and Compatibility

In terms of features, DOCX files have a clear advantage. Since they use the Open XML standard, they offer better formatting options right out of the gate. This includes advanced features like charts and tables.

On the other hand, DOC files, while still functional, are an older format with less efficient storage and formatting options. They lack some of the more advanced features available in DOCX files. So, if you re working on complex documents or reports, this could be a downside.

Another thing to consider is compatibility. DOCX files can be easily opened and edited using modernword processors, like Microsoft Office, Open Office, and Google Docs.

However, if you re collaborating with someone using an older version of Word, then you might need to use the DOC format. This format may not have all the benefits of DOCX, but your document can still be opened and edited in oldersoftware.

4. Document Conversion and Transfer

When it comes to converting and transferring files between the DOC and DOCX formats, it s relatively straightforward. Most modern word processing software, like Microsoft Word, can easily save documents in either format.

If you re working with a DOC file and want to convert it to DOCX, simply open the file, choose Save As, and select the DOCX format.

A DOCX file comprises a collection of XML files that are contained inside a ZIP archive.


If you need to convert a DOCX file to the older DOC format, follow the same process but select the DOC format instead. Be aware that converting to DOC might cause formatting issues, especially if the document uses features exclusive to DOCX.

This shouldn t be a problem for most documents, but it s something to be aware of. You ll also find a variety of online conversion tools that can help you convert between DOC and DOCX formats. These tools allow you to upload your file, choose the desired format, and then download the converted file.

If you re using older versions of Microsoft Word (2003 or earlier), then you ll need to install acompatibility packto open, edit, and save DOCX files. This compatibility pack extends support for DOCX files to older versions of the software, so you can work on these files more easily.

History of DOC and DOCX Formats

In the early days, Microsoft Word used the DOC format, which was introduced with MS-DOS. It became the default file format for Microsoft Word until Word 2007.

The DOC format saved your documents as binary files, which included all the formatting and related data. While functional, the binary format had its limitations with larger file sizes and vulnerability to corruption.

The DOCX format was introduced in Word 2007 as a more advanced and efficient successor to the DOC format. Based on Open XML standards, DOCX files are essentially a collection of XML files inside a zip container. This new approach allowed for smaller file sizes, increased compatibility, and improved security.

Since Word 2007, Microsoft has continued to advance the DOCX format while still maintaining support for the older DOC format. This ensures that your documents remain accessible, regardless of the version of Microsoft Word you are using.

DOC vs DOCX: 7 Must-Know Facts

  1. DOC was the primary file format for Word documents until it was replaced by DOCX with the release of Microsoft Office 2007.
  2. DOCX documents can actually be smaller because the DOCX format uses ZIP compression.
  3. Even though DOCX files are more compatible, some older versions of Word cannot open DOC files.
  4. DOC files can be opened by nearly every version of Microsoft Word, which isn t the case for DOCX files.
  5. The DOC format is owned by Microsoft, but DOCX is based on the Open Office XML format.
  6. DOCX has a ton of features that support collaborative work, like tracking and commenting.
  7. Both formats support text formatting options like fonts, colors, headers, footnotes, footnotes, and styles.

DOC vs DOCX: Which One Is Better? Which One Should You Use?

When comparing the advantages and limitations of DOC and DOCX file formats, it s important to note that both have their unique characteristics. Since DOCX is the newer version of the two, it offers many improvements over the older DOC format.

When it comes to functionality, DOCX might be the better option. Simply because it s compatible with more modern software and can easily convert to other formats. However, if you need to collaborate with someone using an older version of Word, then the DOC format might be better.

The main limitations of both formats come down to compatibility and functionality. For instance, DOC files may not support certain features introduced in newer versions of Word, likeOffice 365, making it difficult to take advantage of the more advanced options.

While DOCX files can be opened in older software, the formatting and compatibility might not be perfect, leading to occasional errors or awkward formatting. Ultimately, the choice between DOC and DOCX depends on your specific needs, preferences, and the word processor you re using.

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