Word (Microsoft Word)
The file format that made word processing standard on every desk and in every office for four decades.
| Full name | Microsoft Word |
| Extension | .doc |
| MIME type | application/msword |
| Developer | Microsoft |
| Released | 1983 |
| Type | Document |
| Binary format | OLE Compound File Binary (Word 97–2003) |
| Succeeded by | .docx (Office Open XML, 2007) |
What is a DOCX file?
The .doc format is the original Microsoft Word document format, first released in 1983 alongside Word 1.0 for MS-DOS. It stores text, formatting, images, and embedded objects in a single binary file. For more than two decades it was the default format for Word and the most widely exchanged document type in the world.
A .doc file is a binary document format created and owned by Microsoft. It holds a full document — text, fonts, paragraph styles, tables, images, and metadata — in a structured binary container. From Word 97 onward, the format uses the OLE Compound File Binary standard, which organises content into internal streams much like a mini file system inside a single file. The format is not plain text: you cannot open it in a text editor and read it directly.
History
Microsoft Word was created by Charles Simonyi and Richard Brodie, two former Xerox PARC programmers hired by Microsoft in 1981. Word 1.0 shipped for MS-DOS in 1983, introducing the .doc extension. The binary format was revised with every major Word release but reached its most widely supported version with Word 97, which defined the spec used through Word 2003. Microsoft replaced .doc as the default with the XML-based .docx format in Word 2007 and published the full binary specification publicly in 2008.
How it works
Word 97–2003 .doc files are Compound File Binary (CFB) documents, a format that embeds a hierarchical storage system inside a single file. The main content stream is called WordDocument and holds the raw character sequence. A separate stream, named 1Table or 0Table, contains formatting records, styles, and document properties. Images and OLE objects are stored in their own sub-storage areas. This layered design made the format flexible but also opaque and difficult to parse without the official specification.
What it is used for
- Writing and sharing business letters, reports, and contracts
- Exchanging documents with organisations still running Office 2003 or earlier
- Archiving legacy documents created before the shift to .docx
- Opening and editing files received from older government or legal systems
How to open it
Microsoft Word opens .doc files natively on Windows and macOS. Free alternatives including LibreOffice Writer, Google Docs (via upload), and Apple Pages also support the format with good but not always perfect fidelity.
Pros and cons
Strengths
- Universal recognition — virtually every word processor can open it
- Rich formatting support including styles, tables, images, and tracked changes
- Single binary file makes it easy to attach and send by email
- Decades of software support means legacy files stay accessible
Trade-offs
- Binary format is harder to repair if the file gets corrupted
- Larger file sizes compared to the newer .docx format
- Not an open standard — parsing it accurately requires Microsoft's specification
- Superseded by .docx, so some newer Word features are not available in .doc
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DOCX FAQ
What is the difference between .doc and .docx?
.doc is a proprietary binary format used by Word 97 through Word 2003. .docx is the XML-based successor introduced in Word 2007. .docx files are smaller, more repairable, and based on an open standard (Office Open XML). Most software today saves to .docx by default.
Can I open a .doc file without Microsoft Word?
Yes. LibreOffice Writer, Google Docs, Apple Pages, and WPS Office all open .doc files. Formatting may shift slightly for complex documents, but basic content renders correctly in all of them.
Is the .doc format still safe to use?
.doc files can contain macros, which have historically been used to distribute malware. If you receive an unexpected .doc file, open it in a viewer or disable macros before enabling editing. The format itself is not going away, but .docx is the safer and more modern choice for new documents.
Who created the .doc format and when?
Microsoft created the format and first shipped it in 1983 with Word 1.0 for MS-DOS. The application was built by Charles Simonyi and Richard Brodie. The most enduring version of the binary format — Word 97 — was released in 1997 and remained the standard until Word 2007 introduced .docx.