DOC vs DOCX: differences and ways to convert between

22 March 2024By Alice

If you are accustomed to working with text documents, you will certainly have encountered files with DOC and DOCX extensions over the years. Although these formats are very similar, there are a few differences to keep in mind when working with these extensions. Read this article to find out what the main differences between DOC and DOCX are and how to convert one format to the other.

DOC vs DOCX: differences and ways to convert between

What are DOC and DOCX files?

At first glance, both DOC and DOCX may appear similar, but they diverge significantly in their underlying structures and functionalities:

DOC (Word Document)

  • DOC, short for “Word Document,” is the earliest format introduced in 1983 with Microsoft Word versions prior to Word 2007. It stores text and formatting information, including images, tables, page layouts and more. It is often used to store documents and can be opened and edited in many word processing programmes.
  • DOC files are based on the binary interchange file format (BIFF), which stores information as binary files. In a DOC file, data are organised as a collection of records and structures arranged in binary streams.
  • DOC files are prone to compatibility issues across different platforms and software versions due to their proprietary nature.
  • They have a greater risk of corruption and file size limitations compared to newer formats like DOCX.

DOCX (Office Open XML Document)

  • DOCX is the successor to DOC and was introduced with Microsoft Word 2007.
  • It employs the XML-based file format, which organizes document data in a more structured and interoperable manner.
  • DOCX files are smaller in size and less prone to corruption. DOCX stores the document in an open XML format that is finally archived as a compressed zip format. This reduces the overall size of the DOCX file compared to the corresponding DOC file with the same content.
  • They offer enhanced compatibility with other software applications and platforms, promoting seamless document exchange. Furthermore, with each new version of Microsoft Word, the DOCX file format becomes richer in functionality, and backward compatibility for embedding the same in DOC file format is no longer supported.

When to Use DOC or DOCX?

The choice between DOC and DOCX hinges on various factors, including compatibility requirements, document complexity, and personal preferences. Here are a few examples:

DOC Usage

  • Legacy compatibility: If working with older versions of Microsoft Word or other word processing software that do not support DOCX, using DOC is advisable.

DOCX Usage

  • Interoperability: For compatibility across different platforms, devices, and software applications, opting for DOCX ensures smoother document sharing and collaboration.
  • Modern features: Using DOCX enables access to advanced features introduced in newer versions of Microsoft Word, such as improved security options, enhanced formatting tools, and better integration with cloud services.

Converting Between DOC and DOCX

After learning the differences between the two formats, their uses and the pros and cons of each, you may need to convert your documents into the required format. Converting documents between DOC and DOCX formats can be done using various tools and methods. Let’s have a look at the most common ones.

How to Convert from DOCX to DOC

Microsoft Word

If you have any version of Microsoft Word released after 2007, you can convert a DOCX file to DOC directly within Word, simply by opening and saving the document in the required format.

Open the document in Microsoft Word.

Click on File and select Save As in the menu on the left. Then choose the folder in which you want to save the file.

DOC vs DOCX: differences and ways to convert between

Choose the desired format (DOC or DOCX) from the drop-down menu.

DOC vs DOCX: differences and ways to convert between

Click Save to convert the document to the selected format.

The same process also applies if you use Word on a Mac.


Pages is the analog of Word in the Apple environment and can also be used to convert DOCX files to DOC.

To do so, select the document to be converted, right-click on it and select Open with > Pages from the menu that opens. Once Pages is open, in the File menu, click on Export as > Word, which can be found in the top left-hand corner, and click on Advanced Options in the window that opens. Now set the option .doc (compatible with Word 1997-2004) in the Format drop-down menu, click on the Next button, set the name and destination folder of the output file, and click on the Export button to save your document in DOC format.


CloudConvert is an online сonverter that allows you to process more than one file at a time, perfect if you have a large amount of documents and want to save time. The site is free of charge but has limitations, so if you need to convert a large number of files or very heavy files (the difference is in the conversion time, not in the number of files) you may consider purchasing a paid profile.

Simply upload the documents, choose which format you want to convert from and to which (you can apply a single choice for all the documents you upload or choose singularly in case you need different output formats), then click on Start conversion and Download once the files are ready.

Other online converters you might want to try are Mconverter, ZamZar, Online Convert and Convertio.

How to convert from DOC to DOCX

Converting from DOC to DOCX can be done in word processors. Let’s see how to convert a DOC file to a DOCX file with the help of ONLYOFFICE Desktop Editors.

ONLYOFFICE Desktop Editors

Open your DOC file in the editor.

DOC vs DOCX: differences and ways to convert between

In the File tab, click on Save as, then choose the format DOCX in the menu, and save the file by clicking on the button.

DOC vs DOCX: differences and ways to convert between

And it’s done! Your file is ready and you can start working on it.

ONLYOFFICE Online converter

If you prefer an online tool, you can use ONLYOFFICE Online Text File Converter. It’s free, easy to use and safe: all the documents you upload are encrypted and won’t be saved on the server. Let’s see how to use it.

Open ONLYOFFICE online text file converter page and upload the document you want to convert.

DOC vs DOCX: differences and ways to convert between

Choose the needed output format from the drop-down list on the right.

If needed, solve the captcha.

Now click Convert.

DOC vs DOCX: differences and ways to convert between

Your DOCX file is ready, you can download it and start working on it! If you need to open or edit the document, you can use ONLYOFFICE Document Editors that support numerous file extensions, including DOC and DOCX.


Now you know the differences between DOC and DOCX files and the most used tools to convert between between.

If you need a powerful and safe word processor, you might want to consider ONLYOFFICE DocSpace, an online editor for text documents, spreadsheets, presentations, forms and PDFs.

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