DOCX and PDF are the two most common document formats. They look similar when you open them, but they're for different things.
What DOCX is
DOCX is the modern Microsoft Word format (the X is for XML — the file is actually a zip of XML parts inside). It's built for editing: paragraphs, styles, tracked changes, comments. It opens in Word, Google Docs, Pages, and LibreOffice.
What PDF is
PDF — Portable Document Format — was designed by Adobe to make a document look identical everywhere. It pins down fonts, layout, and rasterized graphics so that printing or viewing on any device produces the same result. Editing a PDF is possible but painful; that's the point.
Quick comparison
| Feature | DOCX | |
|---|---|---|
| Editable? | Yes | Barely |
| Preserves layout across apps? | Not always | Always |
| Printable? | Usually | Perfectly |
| Tamper-resistant? | No | Yes (with a password) |
| File size | Smaller | Medium |
Reach for DOCX when
- You're still drafting or co-authoring.
- You need comments, tracked changes, or version history.
- Someone is going to paste bits of it into an email.
Reach for PDF when
- The content is final.
- You want it to look the same on any screen or printer.
- You're submitting it somewhere official.
Converting between them
Both directions are a single drop with Formatly:
Bottom line
DOCX is for writing. PDF is for sharing. Use the one that matches what you're doing right now, and convert when the job changes.