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Microsoft Word DocX vs Doc file extension comparison

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Microsoft Word is one of the most commonly used word editors as it ships with every Windows computer — which account for a majority of PCs globally. If you don’t know already, it saves the files in either Doc or DocX extension, by default, depending on the version of MS-Office you’re running. To understand the distinction between the Doc and DocX extensions, let’s brush up on their history a bit.

Back when Microsoft Word launched for MS-DOS, the word processor used a proprietary file extension to store files. This event gave birth to the commonly used Doc extension (.doc). The Doc extension was a Binary File Format and was chosen as the preferred format to store Word files.

Doc files were capable of containing more text formatting information than other document file formats such as the Rich Text Format (RTF) and HyperText Markup Language (HTML), which were prevalent at the time.

DocX vs Doc file: Microsoft Word comparison | Candid.Technology
Saving a Word file in .Doc extension

The format was unchanged until the launch of Word 97, bringing an updated version of the Doc extension. It was carried forward to Word 2003, and by this time, Word was the de facto standard for a feature-rich word processor.

By the early 2000s, Microsoft had made the Doc format more accessible to competing products and open source programs. This was a gesture welcomed by all, and this allowed a wide range of office productivity suites to read and edit data stored under the Doc extension.

However, some advanced formatting features of Word weren’t fully supported by other word processors. This made Word the indisputable king of word processors and helped it maintain dominion over other products such as Corel’s WordPerfect and IBM’s Lotus.

After the release of Word 2003, Microsoft faced stiff competition from open-source software such as Open Office with its Open Document Format (ODF), and compatibility issues with other word processors did not help. The closed nature of the Doc format was under scrutiny, and this led to Microsoft’s development of an extension that had wider accessibility and a broader open standard.

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Office 2007 introduced DocX

This pursuit led to the introduction of the Office Open XML, a combination of formats based upon Extensible Markup Language instead of the binary-based format. Unlike the Doc format which stored data in a binary file, usage of the Open XML format made it possible to store document data as a collection of separate files and folders, all compressed into a zip package.

DocX vs Doc file: Microsoft Word comparison | Candid.Technology
Saving the Word file in .DocX extension

Microsoft began adoption of the Open XML formats in Office 2007, bringing a much-needed change to Word’s primary storage format. Word 2007 used the default extension DocX (.docx), indicating Microsoft’s willingness to adapt to the ever-changing needs of consumers.

However, Microsoft acknowledged the fact that some consumers might prefer to continue using older versions of Word, so the option to manually store a file using the Doc extension was incorporated into the software. Microsoft also rolled out compatibility updates to ensure older versions of Word could still open files using the DocX extension.

Benefits of DocX over Doc extension

Using the DocX format also has a wide range of benefits, few of the major ones have been listed below.

  • Files stored using the Doc extension used a lot of storage space, whereas files using the DocX format utilise a fraction of the space occupied by the older format. The light and small files are easier to read and transfer.
  • The open-source nature of Office Open XML makes it easy for online word processors to read and edit files stored using the DocX format.
  • Using the DocX extension also allowed for the inclusion of data such as document review notes and formatting information within the DocX file itself.

DocX is now the extension of choice for word processors to store document data, and it has become far more widespread than the Doc extension ever was. The only reason to manually use the Doc extension would be to send a file to a client, customer or friend who uses a version of Word that predates Word 2007, or to work with a really out of date word processing software.

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Prathik Jayaprakash

Prathik Jayaprakash