EveryTool
Add Word files, put them in order, and download one .docx. Each part keeps its own fonts, styles, tables, pictures, numbered lists, headers and footers. Nothing is uploaded.
Add at least two files to begin.
Combine chapters, reports, letters or assignments into one Word file in the order you choose. The first file's paper size and margins start the document, and every other file keeps its own page setup, fonts and styles, just like Word's "Keep source formatting". Comments are left out. Old .doc files need to be saved as .docx first. Everything runs in your browser.