Can I convert a Word document without uploading it?
Yes. A browser can read the XML parts inside a DOCX package and turn headings, paragraphs, lists, tables, links, notes, and common images into simpler web content. MRR Free Tools performs that conversion in a time-limited worker on your device, sanitises the result, and offers separate HTML, Markdown, and plain-text downloads. It does not promise a pixel-for-pixel copy of the Word page layout.
How to use the tool
Choose one DOCX file
The tool checks the ZIP package structure, paths, encryption, entry count, expanded size, and compression ratios before conversion.
Convert in the local worker
Mammoth reads the document content with external file access disabled. A conversion that exceeds the time or output limits is stopped.
Review and download
Read the sanitised preview and conversion notes, then save HTML, Markdown, or plain text as a new file.
At a glance
- Conversion engine
- Mammoth.js 1.13.0
- Compressed DOCX limit
- 24 MB
- Expanded-package limit
- 64 MB across at most 512 entries
- Download formats
- Sanitised HTML, Markdown, and plain text
- Original changed
- No
Content conversion is different from page reproduction
DOCX stores document structure and formatting across XML parts inside a ZIP package. A semantic converter can preserve useful meaning—such as headings, paragraphs, emphasis, lists, tables, footnotes, links, and common images—without reproducing the Word rendering engine.
Page breaks, headers, floating shapes, text boxes, tracked layout, complex styles, fields, and exact font metrics can simplify or move. Use the HTML result for accessible web content or the Markdown and text results for editing and reuse; keep the original DOCX when exact pagination matters.
- Review tables, lists, links, notes, and image order after conversion.
- Keep the original for signatures, tracked changes, page layout, or legal records.
- Use the conversion notes to find content Mammoth could not map directly.
What the safety checks do
Before conversion, the tool inspects the DOCX ZIP directory without unpacking it. It rejects encrypted packages, unsafe or duplicate paths, symbolic links, unsupported compression, suspicious expansion ratios, too many entries, and packages above the stated memory limits.
The converter runs in a disposable worker that can be cancelled or terminated after 20 seconds. HTML then passes through a strict sanitiser. Scripts, forms, frames, styles, active content, remote images, unsafe links, and unsupported embedded media are removed before preview or export.
Important limitations
- Legacy .doc files are not DOCX packages and are not supported.
- The result is a semantic conversion, not an exact visual copy of Microsoft Word.
- Password-protected, encrypted, damaged, unusually large, or suspicious packages are rejected.
- Macros are not executed, and remote media or active content is not included.
- Always compare important converted content with the original document before publishing it.
Questions people ask
Is my Word file uploaded?
No. The selected DOCX is inspected and converted in the current browser tab. The packaged conversion engine does not call a document service.
Why does the preview look different from Word?
The tool preserves document meaning where possible, but a web page does not reproduce Word pagination, floating objects, fonts, headers, or every style rule.
Can the converted HTML contain scripts?
The exported HTML is sanitised and includes a restrictive content security policy. Scripts, forms, frames, objects, remote images, unsafe links, and inline Word styling are removed.
Can I open an old .doc file?
No. The older binary .doc format is different from the ZIP-and-XML DOCX format. Convert it to DOCX in a trusted desktop editor first.
Primary and project sources
- Mammoth.js project and documentation — Mammoth.js maintainersUpstream browser-capable DOCX-to-HTML conversion project and security guidance.
- DOMPurify project — DOMPurify maintainersHTML sanitiser used after document conversion.
- Structure of a WordprocessingML document — Microsoft LearnPrimary overview of the XML parts and document structure inside DOCX.