PDF vs Word: Which File Format Should You Use?

PDF and Word documents can contain exactly the same text, yet they behave very differently once you send them to someone. Choosing the right one avoids the two classic problems: a carefully designed document that looks broken on the recipient's computer, and a document someone needs to edit but can't.

The short answer

Use Word (DOCX) while a document is still being written or edited, especially with other people.
Use PDF when a document is finished and must look the same for everyone.

Most documents start life as Word files and end up as PDFs.

How they differ

	PDF	Word (DOCX)
Layout	Fixed – identical on every device	Reflows depending on fonts, software and settings
Editing	Difficult; needs special software or conversion	Easy in Word, LibreOffice or Google Docs
Opens on	Every browser, phone and computer	Needs a word processor or online viewer
Fonts	Embedded in the file	Taken from the reader's computer
Printing	Prints exactly as shown	May shift if fonts or printer settings differ
Collaboration	Comments only	Track changes, comments, co-editing
Forms	Fillable forms and signatures	Possible but less common

Which format for which document?

CVs and job applications

Send a PDF, unless the employer asks for Word. A PDF guarantees that your layout, fonts and page breaks stay exactly as you designed them, whichever computer the recruiter uses. Some application systems ask for DOCX because they extract text automatically – follow the instructions in the job advert.

Contracts and agreements

Draft in Word so both parties can track changes; send the final version as PDF for signing. A PDF makes it clear which version was agreed.

Invoices and quotes

PDF. Invoices should not change after they are sent, and every client can open them.

Reports and proposals

Use Word while colleagues are reviewing, then send the client a PDF.

Forms

If people should fill the form in and send it back, a fillable PDF form works well. If they need to change the structure – add rows, rewrite sections – send Word.

Shared drafts and templates

Word. The whole point is that others can edit them.

Converting between the two

Because most documents need both formats at some stage, converting is common:

Word to PDF is reliable: the layout is fixed exactly as it appears. You can use File › Save As › PDF in Word, or the Word to PDF converter if you don't have Word installed or received a DOC, ODT or RTF file. Our guide how to convert Word to PDF covers the details.
PDF to Word is harder, because a PDF stores positions rather than paragraphs. A good converter rebuilds paragraphs, headings, lists and tables so you can edit them – see how to convert PDF to Word. Keep the original Word file whenever you can; it's always the best source for edits.

What about security?

Neither format is automatically "secure". A PDF can be password-protected against opening, but anyone who can read a PDF can still copy or photograph its content. Word files can also be password-protected. For sensitive documents, think about who receives the file and how you send it, rather than relying on the format alone.

Note that password-protected files can't be converted by our tools – the password has to be removed first.

Frequently asked questions

Is PDF smaller than Word?

It depends on the content. Text-only documents are small in both formats. PDFs with embedded fonts and high-resolution images can be larger; Word files with many images can be large too.

Can a PDF be edited?

Yes, with a PDF editor or by converting it to Word first. Small corrections are usually easiest in the original Word file.

Which format do search engines prefer?

Both can be indexed. For content you want people to find and read online, a normal web page is better than either.

Summary

Word is for documents that are still changing; PDF is for documents that are finished and must look identical everywhere. Write and collaborate in Word, then convert to PDF to share, sign, print or archive – and keep the Word original for future edits.