Free online DOC to DOCX converter

A current word processor, document-management system, or collaboration platform may reject a legacy .doc file and require .docx for editing or upload. Converting can also reduce file size, improve compatibility with current office software, and prevent problems when sharing or archiving the document.

What the DOC format is

.doc is Microsoft Word’s proprietary binary document format, used by default through Word 2003 and still supported for compatibility in later versions. It can contain text, formatting, images, tables, fields, comments, tracked changes, embedded objects, and VBA macros.

DOC files remain common in older business records, email attachments, government archives, and documents created on older computers. Modern word processors can usually open them, but some upload systems and document-management platforms accept only newer formats. Legacy layout features, fonts, equation editors, and embedded objects may also behave differently in current software.

What the DOCX format is

.docx is the default Microsoft Word format introduced with Office 2007. It uses Office Open XML: a ZIP package containing XML document parts and separate resources such as images. The structured package is generally smaller than an equivalent DOC file and is easier for compatible applications and automated systems to inspect or process.

DOCX is widely supported by current Microsoft Word, LibreOffice Writer, Apple Pages, and other office software. It supports modern Word features and is based on a standardized document format, although applications can still interpret advanced formatting differently.

DOCX cannot store VBA macros. If the source DOC contains macros that must remain usable, save it as .docm instead and verify the macro code after conversion. Saving a macro-enabled DOC as DOCX can remove the macros.

How to convert the file

Microsoft Word

1. Open the .doc file in Microsoft Word 2007 or a later desktop version.
2. Select File → Save As. Choose a new filename so the original DOC remains unchanged.
3. Set the file type to Word Document (*.docx).
4. Select Save. If Word displays a compatibility or format warning, confirm that you want to use the current Word format.
5. Close and reopen the new DOCX file. Check page breaks, fonts, tables, images, headers, footers, fields, footnotes, section breaks, and tracked changes.

Word’s F12 shortcut commonly opens the Save As dialog on Windows, but the menu path is available when the shortcut is unavailable. Microsoft Word for the web can open and save many DOC files, but the desktop application provides better control over legacy features and conversion warnings.

LibreOffice Writer

1. Open the DOC file in LibreOffice Writer.
2. Select File → Save As.
3. Choose Word 2007–365 (*.docx) as the file type.
4. Accept Use Word 2007–365 Format if Writer asks whether to use the selected format.
5. Save a separate DOCX copy and inspect its layout in the software that will receive or edit it.

Convert online on 101convert.com

You can convert the file on 101convert.com for free without installing software: upload the DOC file, select DOCX as the output format, start the conversion, and download the result. Do not upload confidential or regulated documents unless the service’s current privacy, security, and retention terms are appropriate for their contents.

Quality and compatibility checks

Basic text, paragraph formatting, tables, and common images normally transfer correctly, but conversion can change pagination and line wrapping. Confirm that the required fonts are installed; font substitution can alter page breaks even when the conversion succeeds.

Pay particular attention to section breaks, columns, headers and footers, footnotes, fields, charts, text boxes, forms, linked OLE objects, embedded files, outdated equation editors, and third-party add-ins. These features may be replaced, flattened, disconnected, or omitted when the source format and target application support them differently.

Password-protected or encrypted DOC files may require the password before conversion. A digital signature on the original file will not remain valid after saving a new DOCX, because the converted file is a different file. Keep the original DOC for reference, and in Word use File → Info → Check for Issues → Inspect Document to review comments, hidden metadata, and embedded content before distributing the converted copy.