DOCX, XLSX, and PPTX as ZIP files
Office documents are ZIP-based packages containing XML, media, and document metadata.
Quick comparison
| Question | DOCX | XLSX / PPTX |
|---|---|---|
| Best for | Simple sharing, broad compatibility, quick inspection. | Specialized workflows, stronger compression, or platform-specific packaging. |
| Privacy risk | The main privacy risk is not the format itself; it is uploading the archive to a third-party service when it contains sensitive files. | |
| Common failure | Corruption, unsupported compression method, or wrong extension. | Missing parts, unsupported app, encryption, or format-specific metadata. |
Practical recommendation
Use ZIP when recipients need the easiest opening experience. Use specialized formats only when compression ratio, package structure, or platform convention matters. For private files, prefer local tools before upload-based services.