doc to docx converter
Convert old .doc files to modern .docx format free — smaller file size, better compatibility, no upload required.
.doc — old format
❌ No internal compression
❌ Larger file size
❌ Word 97–2003 era
❌ Limited compatibility
.docx — modern format
✅ ZIP-based compression
✅ 20–40% smaller
✅ Word 2007 and later
✅ Google Docs, LibreOffice
Click to choose .doc files or drop them here
Only .doc files — outputs .docx
⚠️ Complex formatting, macros, and legacy features may not convert perfectly. Always review your converted file before sending.
Conversion runs entirely in your browser using the mammoth.js library — your files never leave your device. Each .doc file is converted and downloaded individually as a .docx file.
Why convert .doc to .docx?
The .doc format dates back to Word 97. It has no internal compression and is not fully supported by modern software. Converting to .docx gives you a smaller, more compatible file that opens correctly in Word, Google Docs, LibreOffice and Pages.
File size difference
A typical .doc file converts to a .docx that is 20–40% smaller because .docx uses ZIP compression internally. A 5 MB .doc file often becomes 3–4 MB as .docx — without losing any content.
Compatibility
.docx opens in: Microsoft Word 2007+, Google Docs, LibreOffice, Apple Pages, WPS Office, and virtually every modern word processor.
.doc struggles with: Google Docs (imports with warnings), newer Word versions (compatibility mode), mobile apps.
FAQ
Will my formatting be preserved?
Most formatting converts correctly — headings, paragraphs, bold, italic, tables and lists. Complex elements like macros, custom styles and legacy drawing objects may not convert perfectly.
Can I convert multiple files at once?
Yes — drop multiple .doc files and each one is converted and downloaded individually as its own .docx file.
Is my file uploaded to a server?
No — conversion runs entirely in your browser using mammoth.js. Your documents never leave your device.
What if my converted file looks different?
For documents with complex formatting, open the .docx in Microsoft Word and use File → Save As → Word Document to get the best possible conversion using Word's own engine.
Is this free?
Yes — completely free, no sign-up, no limits on 727ave.com.