All formats

PDF vs DOCX

PDF fixes the layout, so it looks the same on every device and is the right format for anything final: contracts, invoices, submissions. DOCX is editable and reflows, which is what you want while the document is still being written. Send PDF, edit DOCX.

Side by side

SpecPDFDOCX
TypeDocumentDocument
Extensions.pdf.docx
Introduced19932007
CompressionBothLossless
MIME typeapplication/pdfapplication/vnd.openxmlformats-officedocument.wordprocessingml.document
Use it whenThe layout must not change: contracts, invoices, reports, print-ready files.A document is still being written, reviewed or collaborated on.
Avoid it whenThe content is still being written or needs to reflow. Keep it in DOCX or Markdown until final.Sending a final deliverable where layout must be guaranteed. Export to PDF.

Where the usual answer breaks

Forms people have to fill in. A PDF form is fiddly to complete on a phone; a DOCX is not, if the recipient has Word.

PDF

  • Layout, fonts and pagination are identical everywhere
  • Supports digital signatures, encryption and form fields
  • PDF/A is a recognised standard for long-term archiving
  • Hard to edit, because it describes a page rather than a document structure
  • Reflows badly on small screens
  • Text in a scanned PDF is just an image until OCR is run
Full PDF guide →

DOCX

  • Editable, with tracked changes, comments and styles
  • Open standard, so many applications can read and write it
  • Content reflows to fit the screen or page
  • Layout can shift between applications and platforms
  • Not suitable as a final, fixed-layout deliverable
Full DOCX guide →

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Last updated 2026-08-03