The Differences Between DOC and DOCX

Published at April 01, 2023


The primary differences between the DOC and DOCX file formats lie in file size and compression, structure and accessibility, compatibility and interoperability, and security and data integrity. DOCX, being the more modern format, offers improved compression, an open and accessible XML-based structure, better compatibility with advanced features, and more robust security. Although both formats have their use cases, the DOCX format is generally the more efficient and versatile choice for modern word processing needs.

In today’s ever-evolving digital landscape, file formats are more important than ever. When it comes to word processing, the two dominant formats are Microsoft Word’s DOC and DOCX. This article dives deep into their differences and explains why it matters which one you choose.

Overview: DOC vs. DOCX

Microsoft introduced the DOC format with Word for MS-DOS in 1983, which quickly became the de facto standard for word processing. However, in 2007, Microsoft released Office 2007, which introduced the DOCX format as the new default file format for Word documents. Despite being similar in appearance and functionality, there are critical differences between the two.

File Size and Compression

DOC files use a proprietary binary format, making them more substantial and often harder to compress. In contrast, DOCX files use a zipped, XML-based format that results in smaller file sizes and improved compression. This is particularly useful when sharing documents via email or cloud storage, where file size limitations can be a concern.

File Structure and Accessibility

The DOC format’s binary structure makes it difficult to access and edit without Microsoft Word or a compatible application. However, the DOCX format’s XML structure is open and human-readable, allowing for better accessibility and compatibility with various applications, even non-Microsoft ones.

Compatibility and Interoperability

Although the DOC format is universally recognized and compatible with most word processing applications, the more modern DOCX format has some advantages. For instance, DOCX files are less prone to corruption and support advanced features like SmartArt, improved formatting, and better support for charts and images. It’s essential to note that while newer versions of Word can open both DOC and DOCX files, older versions of Word (pre-2007) will require a compatibility pack to access DOCX files.

Security and Data Integrity

The XML-based structure of DOCX files enables a more reliable recovery process when faced with file corruption or data loss. In addition, the open standard of the DOCX format allows for better collaboration with third-party applications and data interchange. This, combined with the improved compression, makes DOCX a more secure and robust file format option.


While both the DOC and DOCX formats have their merits, the DOCX format emerges as a more efficient, secure, and versatile option for modern word processing needs. Its improved compression, accessibility, and compatibility with newer features make it the ideal choice for those looking to keep up with the ever-changing digital world.

When choosing a file format for your documents, consider the needs of your project and the audience you’re targeting. While the DOC format still holds relevance and compatibility, the DOCX format brings many benefits that might be the determining factor in your choice.