Choose DOCX or ZIP mode
Use DOCX mode for .docx files and ZIP mode for .zip archives. The modes use different merge rules. Switching modes clears the current file list, and only files accepted for the selected mode remain available.
Merge files in three steps
- Pick DOCX mode or ZIP mode at the top.
- Add at least two accepted files; the merge starts automatically when a valid pair is available.
- Drag the files to set their order or change the relevant option; a valid pair is merged automatically.
The displayed order is the merge order. The tool keeps at most 30 files, with a combined selected-input limit of 200 MB.
DOCX merge options and preservation rules
DOCX mode copies body content such as headings, paragraphs, tables, and lists. It also handles basic paragraph and character styles, numbering, media, and referenced relationships.
Choose one of the visible options:
- Page break (single header/footer set) adds a page break between documents and uses one header/footer set.
- Section break (per-document header/footer, where supported) attempts to add a separate section for each document and copy its header/footer.
- None - append directly joins the document bodies without an added break.
Styles from later documents may be imported under their existing style IDs. If a style ID conflicts, the earlier definition is kept and a warning may be added. Numbering IDs are remapped to avoid collisions. Body media is copied when its referenced package part is available, but unsupported relationship targets, embedded objects, and some header/footer media may not remain functional; detected issues are reported.
DOCX packages missing word/document.xml are skipped, and fewer than two valid DOCX files causes the merge to fail. Unsupported-content checks apply only to documents after the base document.
ZIP duplicate-file policies
Choose how duplicate archive paths should be handled:
- Rename - add a numbered suffix keeps both entries under different names.
- Keep first - ignore later duplicates keeps the first entry.
- Keep last - later entry replaces earlier one keeps the later entry.
- Stop - halt the merge on first conflict stops at the first duplicate, shows an error, and produces no output.
For the successful policies, duplicate-path decisions can be listed in the merge report. ZIP entries with absolute paths, drive letters, or .. path segments are blocked and reported.
Limits and local processing
The selected files are read and merged in your browser. The tool keeps at most 30 files and accepts 200 MB of combined selected input. The merger does not upload selected files, and the original source files are not modified.
Unsupported or unreadable input and merge reports
This page accepts only DOCX or ZIP files in the matching mode. PDFs, PPT/PPTX files, JSON, XML, log files, and EML/MBOX email archives are rejected. Unreadable or malformed DOCX or ZIP input can stop the merge and show an error.
A successful merge can show a best-effort report for conflicts, warnings, blocked entries, and skipped items. In DOCX mode, unsupported-content checks run only for documents after the base document. If ZIP mode stops on a duplicate, the tool shows an error instead of the normal result report.
Frequently asked questions
Can this tool merge PDF or PPTX files?
No. PDFs, slide decks, JSON, XML, log files, and email archives each have their own merge semantics and belong in dedicated tools - use the Merge PDF or Slide Merger tools for those formats. This tool only handles DOCX documents and ZIP archives.
Does DOCX mode preserve headers and footers?
The tool attempts to copy headers and footers. Section break (per-document header/footer, where supported) attempts to give each document its own section, while Page break (single header/footer set) and None - append directly use one header/footer set. Some header/footer references or media may remain unresolved.
What happens to duplicate paths in ZIP mode?
Choose Rename - add a numbered suffix, Keep first - ignore later duplicates, or Keep last - later entry replaces earlier one to complete the merge. Stop - halt the merge on first conflict shows an error and produces no output.
Does it upload my files anywhere?
No. The selected files are read and merged locally in your browser using JSZip and the File API; the merger does not upload them. Your original source files are never modified.