CalcBrew

Document Converters

DOC to DOCX

Bring old .doc files into the present: DOCX opens everywhere, supports modern features and is what web apps and phones expect.

Processed on our EU server over HTTPS and deleted automatically within 1 hour.

Drop Word 97–2003 (DOC), RTF, ODT files here

or click to browse · paste from clipboard · up to 200 MB each

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Why convert Word 97–2003 (DOC) to Word (DOCX)

DOC is a binary format that many web tools no longer read and that Word opens in restricted Compatibility Mode. DOCX is XML-based, smaller, and the native format of Word, Google Docs, LibreOffice and Pages.

The conversion runs through a full office engine on our server, which handles the old binary format’s quirks — embedded objects, fields, legacy numbering — better than lightweight converters.

How it works

  1. Drop Word 97–2003 (DOC), RTF, ODT files onto the box above, click it to browse, or paste from the clipboard.
  2. Check the file list; remove anything you added by mistake.
  3. Press Convert. The file is uploaded securely, converted, and the result is offered for download.
  4. Download the Word (DOCX) — individually or all at once.

About the formats

Word 97–2003 (DOC) · Legacy Microsoft Word document · .doc

The binary Word format used from 1997 to 2003; still opens in Word, but many web apps and phones cannot read it.

  • DOC files are binary, not XML, so they cannot be inspected or repaired as easily as DOCX.
  • Google Docs converts DOC on upload; Word opens it in Compatibility Mode.
  • Macros can live inside DOC files, so some email systems block them.

RTF · Rich Text Format · .rtf

A 1987 Microsoft interchange format that almost any word processor can read: bold, italics, lists and tables, but no modern layout features.

  • RTF is plain text with control codes, so it is safe from macros and easy to repair.
  • Images are stored as hexadecimal text, which makes RTF files with pictures very large.
  • Windows WordPad and macOS TextEdit both save RTF by default.

ODT · OpenDocument text · .odt

The open document format used by LibreOffice and OpenOffice Writer, and required by several governments for public documents.

  • ODT is an ISO standard (ISO 26300) and fully documented, unlike DOC.
  • Word can open and save ODT, but complex formatting may shift.
  • Like DOCX, an ODT file is a ZIP archive containing XML.

Word (DOCX) · Microsoft Word document · .docx

The current Word format (since 2007): a ZIP of XML files that Word, Google Docs, LibreOffice and Pages can all open and edit.

  • DOCX layout depends on the fonts installed on the viewing computer, which is why the same file can paginate differently on another machine.
  • Converting to PDF freezes the layout so it looks the same everywhere.
  • DOCX is part of the Office Open XML standard (ISO 29500).

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Frequently asked questions