PDF and Word are the two most common document formats in the world — and they are designed for completely different purposes. Choosing the wrong one causes unnecessary headaches: formatting that breaks when the recipient opens it, files that cannot be edited when they need to be, and documents that look unprofessional on screen or in print. This guide settles the debate.
The core difference
Word (.docx) is a living document format. It is designed to be edited, revised, tracked, and collaborated on. The layout can shift depending on the software version, operating system, and fonts installed on the recipient's machine.
PDF is a fixed document format. It preserves layout, fonts, colours, and spacing exactly — regardless of what software or device opens it. What you see when you create a PDF is what every recipient sees.
Neither is better in absolute terms. They serve different stages of a document's life.
When to use PDF
- Sharing a final version of any document — proposals, reports, invoices, contracts.
- Submitting forms that should not be modified by the recipient.
- Publishing anything publicly — product guides, brochures, press releases.
- Legal documents where layout and content integrity matter.
- Printing — PDFs print exactly as designed, every time.
- Archiving — PDFs can be made ISO-compliant for long-term storage (PDF/A format).
When to use Word
- Drafting and editing — tracked changes, comments, and version history are Word's strengths.
- Collaborating with colleagues who need to add or revise content.
- Creating templates that will be reused with different content each time.
- Documents that will go through multiple rounds of review before finalising.
The general rule: use Word to create, use PDF to deliver.
For sharing and emailing
PDF wins clearly for sharing. A Word document can look completely different when the recipient opens it — especially if they use a different version of Office, LibreOffice, or Google Docs. Fonts may substitute, tables can shift, and page breaks might move. A PDF is immune to all of this.
For email specifically, PDFs also compress better than .docx files when they contain mostly text. You can reduce a PDF's file size further with the Compress PDF tool before attaching it.
For printing
PDF is significantly more reliable for printing. Because the layout is fixed, what you see on screen is what comes out of the printer — including margins, headers, footers, and page breaks. Word documents sometimes reflow on different printers due to driver differences, causing extra pages or broken layouts.
For print-critical documents like event programmes, menus, brochures, and formal letters, always convert to PDF first.
For long-term storage
PDF is the preferred format for archiving because it is self-contained — fonts, images, and formatting are all embedded in the file. Word documents depend on external fonts and may require the same version of Office to display correctly years later. For compliance, legal, and historical records, PDF (particularly PDF/A) is the standard.
Moving between the two formats
The most common conversion need is Word to PDF before sharing — your word processor's "Export to PDF" or "Save as PDF" function handles this natively.
Going the other direction — extracting text content from a PDF — is handled by PDFflow's PDF to Text tool. It extracts all readable text from a PDF so you can paste it into a Word document for further editing. This is useful when someone sends you a final PDF and you need to revise the content.