Microsoft Word 97-2003 Document (DOC) stores formatted text in a binary compound-document structure, requiring Microsoft Word or a compatible reader to render correctly. Office Open XML Word Document (DOCX) stores text and formatting as zipped XML, relying on the reader's installed fonts to render the final layout. This conversion changes the file's encoding, compression method, and supported feature set. Text content, headings, and basic formatting are transferred; complex features such as macros or embedded objects may not translate fully. The result is a standard DOCX file readable by any compatible application. 1converter handles DOC-to-DOCX conversion server-side: files are uploaded over HTTPS, processed on isolated cloud infrastructure, and the converted output is available for download for 24 hours before automatic deletion. No account is required for standard conversions.