PDF vs DOCX — Stop Sending the Wrong One

The Resume Test

You've probably sent your resume as both PDF and DOCX at some point. And you've probably noticed: the DOCX version looks different on every computer it opens on. Different fonts, shifted margins, broken formatting. The PDF looks identical everywhere.

That's the core difference between these formats, and it applies to every document you'll ever send.

PDF: A Digital Printout

A PDF captures a document exactly as it looks — fonts, layout, spacing, images, colors — and locks it in place. Opening a PDF on a Mac, Windows PC, phone, or browser shows the same document. It's essentially a digital photograph of a page, except the text is still selectable.

PDF is for finished documents. Things you don't want changed.

DOCX: A Living Document

A DOCX file is a set of instructions: "Put this text here in this font at this size with this spacing." The program opening it (Word, Google Docs, Pages) interprets those instructions — and different programs interpret them slightly differently.

DOCX is for documents still being edited. Things that need to change.

The Decision Matrix

Scenario	Use	Why
Sending a resume	PDF	Formatting must survive HR software
Collaborating on a draft	DOCX	People need to edit and comment
Signed contract	PDF	Legally binding, tamper-evident
Internal report being reviewed	DOCX	Reviewers need Track Changes
Final report being distributed	PDF	Readers shouldn't accidentally edit it
Invoice	PDF	Professional, fixed layout
Form to fill out	PDF (fillable)	Structured input, consistent layout
Template to reuse	DOCX	Easy to modify for each use
Academic paper submission	PDF (usually)	Journals require it; reviewers can annotate
Government filing	PDF (usually)	Most agencies require PDF
Email attachment to client	PDF	Looks professional, can't be accidentally edited
Working with a designer	Neither — use their native format	InDesign, Figma, etc.

The Formatting Guarantee Problem

Here's why formatting breaks in DOCX:

1. Fonts: If the recipient doesn't have the font you used, their system substitutes a different one. Different font = different character widths = shifted line breaks = broken layout.

1. Margins: Different default margins across Word versions and regions (US Letter vs A4 paper size) shift content.

1. Version differences: Word 2016, Word 2024, Google Docs, and LibreOffice all render DOCX slightly differently. Microsoft's own versions aren't perfectly consistent.

1. Embedded objects: Charts, SmartArt, equations, and text boxes are the most common formatting casualties.

PDF avoids all of this by embedding the fonts and rendering a fixed layout. The file is larger, but it's guaranteed to look right.

File Size Comparison

Document Type	DOCX	PDF
10-page text document	25-50 KB	100-200 KB
10-page with images	2-5 MB	1-3 MB
50-page report with charts	5-15 MB	3-10 MB
Scanned document (10 pages)	N/A	5-20 MB

Text-only PDFs are larger than DOCX because they embed fonts. Image-heavy PDFs are often smaller because PDF's image compression is typically better than DOCX's.

When People Get It Wrong

Sending a DOCX to a client

Unless they specifically asked for an editable version, send PDF. A DOCX says "this is a draft." A PDF says "this is final."

Sending a PDF for collaborative editing

If three people need to edit a document, a PDF creates a mess of annotation layers. Use DOCX with Track Changes, or better yet, Google Docs for real-time collaboration.

Scanning to DOCX

Scanners should produce PDF, not DOCX. A scanned "Word document" is just an image pasted into Word — it's not editable text. Scan to PDF, then OCR if you need editable text.

Using PDF for web content

PDFs are terrible for web reading. They don't reflow for mobile, they're hard to navigate, and search engines index them poorly. Use HTML for web content, PDF for downloadable documents.

Converting Between Them

DOCX → PDF: Every word processor can do this (File → Save As PDF / Export to PDF). MyPDF's Word to PDF tool handles it online. PDF → DOCX: Trickier. The conversion quality depends on how the PDF was created. PDFs from Word documents convert back almost perfectly. Scanned PDFs or design-heavy PDFs produce messy DOCX files. Use MyPDF's PDF to Word for the best results.

The One-Sentence Rule

If the document is finished, send PDF. If the document is in progress, send DOCX.

That's it. That's the rule.

Related Tools

• Word to PDF — Convert DOCX to PDF
• PDF to Word — Convert PDF back to editable DOCX
• Compress PDF — Shrink PDFs for email
• Sign PDF — Add signatures to finalized documents