Is my Word document uploaded to a server?

No. The conversion runs entirely in your browser using mammoth.js, html2canvas, and jsPDF. Your document never leaves your device — open the Network tab in your browser's developer tools during conversion and you'll see no outgoing requests. This makes the tool safe for confidential contracts, legal drafts, internal reports, HR documents, financial statements, or any other private content where uploading to a third-party service would be unacceptable.

How accurate is the formatting?

Headings, paragraphs, bold and italic, ordered and unordered lists, simple tables, and embedded images are preserved with reasonable fidelity. Complex layouts — multi-column pages, footnotes, headers and footers, comments, tracked changes, equations, and SmartArt — may not render exactly as Word displays them. mammoth.js intentionally targets the semantic content of a document rather than its pixel-perfect appearance, which trades absolute layout fidelity for portability and a clean PDF. For one-page memos, articles, and reports the result is normally indistinguishable from a Word print-to-PDF.

What is the maximum file size?

The tool accepts .docx files up to 50 MB. The actual ceiling is browser memory: a 50 MB .docx that contains many high-resolution images may exhaust memory on lower-spec devices during the html2canvas raster step. If conversion fails on a large file, try splitting the document or downsampling images in Word first. Plain text-heavy documents convert quickly even at the upper size limit.

Why does the converted PDF look different from how Word displays it?

mammoth.js translates DOCX to clean HTML, then a browser-style renderer paints it to PDF. This rendering uses your browser's default fonts and rendering engine rather than Microsoft Word's typesetting engine. Differences typically appear in line breaks, exact spacing, font substitution when a custom Word font is not available in the browser, and table column widths. To minimise drift, stick to common system fonts (Calibri, Arial, Times New Roman) in your source document.

Are tracked changes, comments, or revisions included?

No. mammoth.js extracts the visible accepted content of your document and ignores tracked changes, comments, footnotes, and other reviewer annotations. If you need to preserve revision history or comments in the PDF, accept all changes in Word and resolve comments before converting, or use Word's built-in Save as PDF feature which has options to include markup.

Can I convert .doc, .odt, or .rtf files?

Only the Open XML .docx format is supported. Word 97–2003 binary .doc files, OpenDocument .odt files, and Rich Text Format .rtf files use different internal structures that mammoth.js does not parse. Open the file in Word or LibreOffice and use Save As to convert it to .docx first, then upload here.

Word to PDF Online Free - Convert Word documents to PDF

How It Works

1

Upload

Select or drag & drop your Word document (.docx). The file stays on your device — it is loaded into memory by your browser only and never sent to any server. Only Open XML .docx (Word 2007 and later) is accepted; older binary .doc files must be resaved as .docx in Word or LibreOffice first.

2

Convert

mammoth.js parses the .docx in your browser and produces a styled HTML representation of headings, paragraphs, lists, and basic tables. That HTML is rendered to a high-resolution canvas via html2canvas, then drawn page-by-page into a PDF using jsPDF inside a Web Worker so the main thread stays responsive.

3

Download

Save the generated PDF directly to your device. Output is a standard PDF 1.4 file compatible with every modern PDF reader. Choose page size (A4, Letter, Legal), orientation, and margins before converting to match your needs.

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