DOC to DOCX Converter
Upgrade a legacy Word 97-2003 .doc file to the modern Office Open XML .docx format without installing Office. LibreOffice does the rewrite on our server, so you get an editable Word document back; macros are not carried over, and unusual legacy objects are worth a check.
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Why old .doc files need upgrading
The .doc extension means the Word 97-2003 binary format, a compound file whose layout Microsoft only documented publicly years later, while .docx replaced it with a ZIP archive of XML parts plus the images, which is why far more software reads it properly. Current Word opens a .doc in compatibility mode with some features switched off, and document libraries, review workflows and phone apps generally assume .docx, which is exactly what people reaching this page want: old Word 97-2003 archives upgraded so they stay openable.
Here the conversion runs on our servers through the LibreOffice 7.4 command line in headless mode. LibreOffice loads the binary .doc into its Writer document model and exports it again with the MS Word 2007 XML filter, producing a genuine .docx package you can edit in Word. These files are usually small, so a conversion typically finishes about a second after the upload completes. You do not need Word, a compatibility pack, or any software installed.
What this means in practice: LibreOffice re-saves the document as it reads it, so the words, paragraph and heading styles, tables and embedded pictures usually transfer. It is LibreOffice doing the save, not Word, so anything the old binary format expressed in an unusual way, such as WordArt, embedded OLE objects from 1990s applications, exotic field codes or heavily nested frames and text boxes, can shift position or be approximated. Macros do not survive, and cannot: a plain .docx is not allowed to contain VBA, that is what the macro-enabled .docm format is for, and we do not accept .docm uploads.
Use this when you have inherited a folder of old documents, when someone emailed you a .doc and your editor refuses it, or when a system you are uploading to only accepts .docx. If what you actually need is a fixed, shareable copy rather than an editable one, the same page converts .doc straight to PDF, and .odt, .rtf and .html are available as targets too.
How to convert DOC to DOCX
- Check the file really is a Word 97-2003 document. Files renamed to .doc from something else fail to load, and that is one of the few errors we see on this pair.
- If the document is password-protected, open it in Word (or whichever application wrote it), remove the password and save an unprotected copy. Protection on legacy .doc files is not detected by our checks, so an encrypted file comes back with a generic "could not be opened" message instead of a clear one.
- Drop the .doc files onto this page. Up to 10 files per request without an account, each up to 50 MB; a free account lifts the per-file ceiling to 100 MB.
- Leave the target set to DOCX and start the conversion. The file is uploaded over HTTPS and converted by a worker on our servers.
- Download the .docx within about four hours, open it in Word or Google Docs and skim the headers, footers, page breaks and any diagrams, since those are the parts most likely to need a nudge after a legacy upgrade.
What this converter does
- Reads the Word 97-2003 binary format with LibreOffice and writes a modern Office Open XML .docx package, no Office licence or compatibility pack needed
- Keeps the result editable: body text, styles, tables and images are rewritten as document content, never as a scan or page image
- Finishes in about a second for the small documents typical of this pair, so you can work through an archive quickly
- Converts up to 10 files in one request on the free tiers, 25 on Plus and 50 on Pro
- Offers DOC to PDF, ODT, RTF and HTML from the same page when .docx is not what you need
- Tells you when LibreOffice could not open or process the file instead of handing you a broken download
Video Tutorial
Watch this step-by-step tutorial to learn how to convert DOC files to DOCX format online for free using MiConvert.com. No software installation required.
DOC to DOCX questions
Will my formatting change?
Most documents look much the same afterwards, because LibreOffice reproduces the text, styles, tables and pictures it reads from the old file. Since the save is done by LibreOffice rather than Word, legacy extras such as WordArt, old embedded objects, some field codes and tightly nested text boxes can move or be approximated, so check page breaks, headers and anything graphical once.
Can I convert a .doc without opening it in Word?
Yes, that is the point of this page. The conversion happens on our servers, so you do not need Word, the Microsoft compatibility pack or any local software. Upload the file, download the .docx.
Do macros in my old document survive?
No. A plain .docx cannot store VBA macros by design, so any macro code in the original .doc is not carried into the output. Macro-enabled .docm files are not accepted as uploads either. If you need the macros, keep the original .doc and extract the code from the VBA editor in Word before you archive it.
Can I convert hundreds of files, or script this from Python or PowerShell?
This page is built for one-off files and small sets: 10 files per request on the guest and free tiers, with an hourly limit of 10 jobs per IP address for those tiers (Plus and Pro allow 25 and 50 files per request and 50 jobs an hour). For a folder of several hundred legacy documents, a local loop over Word's Save As, or LibreOffice's own command line on your machine, is the better tool.
My conversion failed with "output file not found. Expected .docx" - what now?
That message means LibreOffice loaded or processed the file but produced nothing usable. The usual causes are a damaged or truncated upload, a file that is not really a Word document despite the extension, or hidden password protection. Open the original in Word, re-save it, and try again; if it still fails, converting to PDF or RTF sometimes gets the content out.
What about a password-protected .doc?
Remove the password first. Encryption in modern Word and ODF files is detected and reported clearly, but the older .doc, .xls and .ppt encryption schemes are not, so a protected legacy file simply comes back as "could not be opened". We do not remove or crack passwords.
Is the .docx smaller than the .doc?
Often, because the XML inside a .docx is ZIP-compressed while the old binary container is not. A document full of already-compressed JPEG photos will be about the same size.
What happens to my document after it is converted?
Your uploaded .doc is deleted as soon as the job finishes, and the converted .docx can be downloaded for about four hours from a random, unguessable link before it is removed automatically. Transfers use HTTPS. File names, sizes and conversion outcomes are logged for operations, and signed-in users get a history row they can delete with their account.