PDF and Word are the two heavyweight document formats, and people often use them interchangeably. They are not. Each is built for a different stage of a document's life.
Use Word when you are still working
Word documents (DOCX) are made for editing. Text reflows, tracked changes work, comments thread neatly, and styles stay consistent as you rewrite.
- Drafting and collaborating on content
- Anything that will change again before it is final
- Documents where layout is not critical
Use PDF when it must look right
PDF is made for presentation. Once a document is final, a PDF locks its appearance so it looks identical everywhere — on a laptop, a phone, a printout.
- Contracts, invoices and official forms
- Anything that will be signed
- Documents shared outside your team
- Archives that must not shift over time
Word is for the workshop. PDF is for the showroom.
Quick comparison
- Editing: Word wins — PDF is not designed for reflow.
- Fidelity: PDF wins — it preserves the exact look.
- Signing: PDF wins — it supports certified e-signatures.
- File size: PDF often smaller for finished documents.
The sensible workflow
Write in Word. Finish in PDF. Convert to Word only when you genuinely need to edit a document you no longer have the source for.
SELKATDocs can move between both: convert Word to PDF when you are ready to share, or PDF to Word when you need to edit.