PDF or Word: which format should you actually use?

PDF and Word were designed to do opposite things, so it makes little sense to rank one above the other. Almost every problem people have with either one comes from using it for the other one's job.

The one difference everything else follows from

A Word document describes intent. A PDF describes appearance.

A .docx says "this paragraph is Heading 1, in Calibri, 16pt". Where that lands on the page is worked out by whatever program opens it. That program has its own fonts, its own line-breaking and its own idea of your printer's margins. Open the same file on a different machine and the text may reflow. This is normal. The format is doing its job, which is to stay editable.

A PDF says "draw this glyph at this coordinate, in this embedded font, at this size". (The ISO 32000-1 specification describes page content in exactly these terms.) Nothing reflows, because nothing is left to decide. Every viewer, every printer, every operating system, twenty years from now: the same page. The cost is that the file no longer has much structure. It is a set of drawing instructions.

Which to use

You need to…	Use
Send something that must look identical for everyone	PDF
Let someone else edit or comment on the content	Word
Print reliably, including at a print shop	PDF
Keep working on it yourself	Word
Sign, or send for signature	PDF
Archive for a decade or more	PDF/A
Get it read well on a phone	Word, or HTML
Collaborate with several people at once	Word, in a shared workspace

The phone row deserves a closer look. A PDF is fixed to a page size, usually A4 or Letter, and a phone screen is neither. Reading a PDF on a phone means pinching and panning. No conversion fixes that, because the main promise of the format is that the layout does not change.

Converting Word to PDF

This direction is straightforward, because you are going from more information to less. The layout gets decided once and frozen. Do this at the end, when the document is finished.

One thing to watch: fonts. If your document uses a typeface the converter does not have, it substitutes something else and your careful spacing changes. Sticking to widely available fonts avoids the problem. Our Word to PDF converter reads the document structure (headings, paragraphs, lists and tables) and lays it out cleanly. That is the right trade for most documents, but it will not reproduce a heavily designed brochure.

Converting PDF to Word

This is the hard direction, and anyone promising perfect results is not being straight with you. You are trying to recover information that was thrown away on purpose.

A converter has to guess, from coordinates alone:

• Where one paragraph ends and the next begins
• Which lines are headings, and at what level
• Which text is a list, and whether it is nested
• Where a table's cell boundaries are, when the PDF has no cells, only lines and text
• Whether two columns are two columns, or one wide one with a gap

Good converters get this right most of the time on a clean, single-column, text-based document. Every converter struggles with multi-column layouts, tables without ruled borders, and anything with text wrapped around a floating image.

And if the PDF is a scan, there is no text to recover at all. You need OCR first, which adds its own errors on top.

Our PDF to Word converter recovers text, headings and lists, and says plainly that it does not reproduce exact layout. It is better to know you will need to tidy the result than to discover it after you have sent it.

A note on PDF/A

If a document has to be readable in twenty years, plain PDF is not quite enough. It can refer to fonts it does not contain, and link to things that will not exist later. PDF/A is the ISO-standardised subset that forbids those dependencies. The Library of Congress describes the PDF/A family in its guide to formats for long-term preservation. Many institutions require PDF/A for exactly this reason, so if you are filing anything official, check whether yours does.

The rule of thumb

Work in Word. Send as PDF. Convert back only when you have no choice, and expect to tidy up afterwards.

If you find yourself converting PDF to Word often, fix it at the source: ask for the original. Whoever made the PDF still has the editable file, and one email saves an hour of reformatting.