DOCX Merge

When you paste one Word document into another, Word has to reconcile two sets of styles, numbering definitions and image links. The usual result is headings in the wrong font, numbered lists that suddenly continue from the previous chapter, and pictures that go missing or change size. Merging at the file level avoids this: the content of every document is carried over together with the definitions it relies on. Pictures and their links get new internal names so they cannot collide, list numbering is kept separate for each document, and styles that exist only in a later document are added to the result.

A Word document has one page setup and one set of headers and footers, so the merged file has to choose. It takes them from the first document in your list — put your template or cover document first.

Assemble a report from chapters written by different team members. Combine a cover letter, CV and references into one application file. Join monthly or weekly reports into a yearly archive. Merge a contract with its appendices, or lesson handouts into a single course pack. If two documents use a style with the same name but a different look, the first document's version wins, which keeps the merged document consistent — make sure the first document uses the styles you want.

Contracts, applications and reports are confidential, so the documents are combined on your device with JSZip, an open-source library; nothing is sent to a server. Each file is checked by its content before it is added: an old Word 97–2003 .doc file, an Excel workbook or a picture renamed to .docx is refused with a clear explanation. Documents up to 100 MB each can be added. Only .docx files are supported; save an old .doc as .docx first.

To combine PDF files instead, use Merge PDF. To make a quick change to the merged document without opening Word, use the DOCX Editor, and to convert the result to a web page, use DOCX to HTML. To turn Word documents into PDF, use Word to PDF.