How do I open a .doc file?

On Windows use Microsoft Word; on macOS use Microsoft Word; on Linux use LibreOffice Writer. The pre-2007 Word format — still readable, but Microsoft would rather you converted it.

Can I convert a .doc file?

Yes. It is usually converted to .docx, .pdf, .odt, .rtf or .txt, either by exporting from one of the programs listed above or with a format converter.

.doc files

.doc file

Word Document (legacy binary)

The pre-2007 Word format — still readable, but Microsoft would rather you converted it.

What opens a .doc file

Windows: Microsoft Word, LibreOffice Writer, WPS Office
macOS: Microsoft Word, Pages (built in), LibreOffice Writer
Linux: LibreOffice Writer, OnlyOffice, AbiWord
In a browser: Google Docs, Word for the web

What a .doc file is

DOC is the binary Word format used from the early 1990s to Office 2003. Modern Word still opens it, though newer versions block it by default in some managed environments because the old binary formats are a common malware vector. LibreOffice and Google Docs read it too; anything with unusual embedded objects is safest converted to DOCX once and kept that way.

Converting it

A .doc file is commonly converted to .docx, .pdf, .odt, .rtf or .txt. It is a binary format, so a text editor will show unreadable characters rather than its contents.

Details

Extension: .doc
Full name: Word Document (legacy binary)
Category: Documents
MIME type: application/msword
Created by: Microsoft
Format: Binary

Common questions

How do I open a .doc file?: On Windows use Microsoft Word; on macOS use Microsoft Word; on Linux use LibreOffice Writer. The pre-2007 Word format — still readable, but Microsoft would rather you converted it.
What is a .doc file?: Word Document (legacy binary). DOC is the binary Word format used from the early 1990s to Office 2003. Modern Word still opens it, though newer versions block it by default in some managed environments because the old binary formats are a common malware vector.
Can I convert a .doc file?: Yes. It is usually converted to .docx, .pdf, .odt, .rtf or .txt, either by exporting from one of the programs listed above or with a format converter.

.pdf — Portable Document Format A fixed-layout document that looks identical everywhere — the format for anythin
.docx — Word Document (Open XML) The standard Word document since Office 2007 — a zip archive of XML underneath.
.xlsx — Excel Workbook (Open XML) The standard Excel spreadsheet since 2007, with a million-row limit per sheet.
.pptx — PowerPoint Presentation (Open XML) The standard PowerPoint deck since 2007.
.txt — Plain Text File Text with no formatting at all — the format that will still open in fifty years.
.xls — Excel Workbook (legacy binary) The pre-2007 Excel format, limited to 65,536 rows.
.ppt — PowerPoint Presentation (legacy binary) The pre-2007 PowerPoint format.
.md — Markdown Document Plain text with a light formatting convention — headings with #, bold with **.
.rtf — Rich Text Format A formatted document format readable by every word processor since 1987.
.pages — Apple Pages Document Apple's word processor format — Apple devices and iCloud only.
.odt — OpenDocument Text The open-standard word processor format, native to LibreOffice.
.eml — Email Message A single saved email, headers and all, in the standard internet message format.

Sources

Media Types Registry — IANA
Official vendor product documentation — At One Place

How these figures are compiled and checked