DOC to DOCX Converter

1. Upload your DOC file (up to 50 MB).
2. Click 'Convert to DOCX' — takes 3-8 seconds.
3. Download the modern DOCX — smaller and more robust.

DOCX is smaller, more robust, and supports modern Word features that DOC can't. Converting upgrades your files to the current standard while preserving formatting.

DOC is a binary format from the 1990s with limitations: larger files, worse corruption recovery, no support for modern Word features (like SmartArt, advanced tables, improved metadata). DOCX is smaller (ZIP-based), more resilient (per-part structure), and unlocked for modern workflows. Converting DOC to DOCX modernizes your document without changing its content.

The converter uses LibreOffice headless to read the DOC binary structure and re-save it as the DOCX XML-based package. Text, images, tables, and formatting are preserved. The output opens in every Word version from 2007 onwards and in modern web editors (Google Docs, Office 365).

• Modernizing a DOC document library.
• Reducing storage costs for legacy documents.
• Preparing old files for modern CMS or cloud systems.
• Migrating documents to Office 365 or Google Workspace.
• Improving email deliverability (smaller files).
• Unlocking modern Word features in old documents.
• Standardizing a mixed DOC/DOCX archive.

DOC → DOCX conversion is layout-preserving. Every element of the binary DOC format has a direct equivalent in DOCX, so there is no quality loss. File size drops significantly (30-50%) because DOCX is ZIP-compressed internally.

• VBA macros are not preserved (DOCX can hold them, but LibreOffice doesn't transfer them).
• Very old Word 6.0/95 DOC files may have font issues.
• Some field codes may need re-linking.
• Track changes are converted as accepted.
• Extremely complex layouts may shift slightly.

• Output DOCX opens in Word 2007+, Office 365, Google Docs.
• Smaller file size for email and cloud storage.
• Accepted by every modern document management system.
• Better crash recovery (per-part XML structure).
• Modern formatting and accessibility features supported.

• DOCX is 30-50% smaller than DOC — great for email.
• Modern features (SmartArt, better metadata) become available after conversion.
• For very old DOC files, check the layout after conversion.
• PDF is a better choice for pure distribution.
• Batch-convert multiple files at once for library migrations.

File size is 30-50% smaller — is something missing?

No. DOCX uses ZIP compression, DOC is uncompressed binary. All content is preserved.

Macros no longer run

VBA macros are not preserved (security). Re-create them in the DOCX if needed.

Layout shifted slightly

Very complex layouts may shift. Open in Word to verify. Standard documents preserve perfectly.

• Microsoft — Word Binary File Format
• Microsoft — Office Open XML