You get sent a document and it won't open properly. Or it opens, but the layout is subtly wrong — spacing off, a table broken, a font substituted. The culprit is usually the format: someone wrote it in one program and you opened it in another.
Three formats account for most of this: DOCX, ODT, and RTF. They all hold formatted text, they all look similar in a file listing, and they all behave differently. This guide explains what each one is, why you keep running into them, and why the reliable answer to "how do I send this so it looks right?" is almost always PDF.
DOCX — the Microsoft standard
The default format of Microsoft Word since 2007, and the de facto standard for business documents worldwide. It's a zipped package of XML files describing your text, styles, images, and layout.
Strengths: it's what everyone uses. Rich feature support — tracked changes, comments, complex layouts, embedded objects.
The catch: "opens in Word" is not the same as "looks identical everywhere." Open a DOCX in Google Docs, LibreOffice, or a different version of Word, and fonts get substituted, spacing shifts, and complex layouts can break. It's a format for editing, not for delivering.
ODT — the open standard
OpenDocument Text, the native format of LibreOffice Writer, OpenOffice, and a few other editors. It's an open ISO standard, which is why many governments and public institutions mandate it.
Strengths: genuinely open, no vendor lock-in, well specified.
The catch: plenty of people simply can't open it. Word handles ODT imperfectly, and a recipient who only has Microsoft Office may see a mangled layout. If you send someone an ODT and they don't use LibreOffice, expect friction.
RTF — the old lingua franca
Rich Text Format is the elder statesman: a plain-text format with formatting instructions embedded in it, dating from the 1980s. It was the original answer to "how do I move a formatted document between different programs?"
Strengths: almost everything can open an RTF. It's the most universally readable of the three, which is why it still turns up in exports, legal templates, and files passed between mismatched systems.
The catch: it's ancient and limited. It handles basic formatting well and modern layout poorly, and the files are often bloated. It survives on compatibility, not capability.
The pattern
Look at what they have in common. All three are editable working formats — designed for the person writing the document. And all three share the same weakness: how the document looks depends on the software that opens it. Fonts substitute. Spacing shifts. Layout reflows.
That's fine while you're drafting. It's a liability the moment you send the document to someone else — because you no longer control what they see.
Which is why you convert to PDF
A PDF is a delivery format. It embeds its fonts and fixes its layout, so it looks the same on every machine and in every reader. It also can't be casually edited, which is usually what you want when you're sending a final version out.
The rule of thumb:
- Editing? Keep it in DOCX, ODT, or RTF — whatever your editor uses.
- Sending, printing, filing, or archiving? Convert to PDF.
Whichever you have, there's a direct route:
Common questions
Someone sent me an ODT and I only have Word. What do I do?
Convert it. ODT to PDF gives you a file you can definitely read, print, and share — no LibreOffice required. If you need to edit it rather than just read it, you'd need an editor that imports ODT properly.
Which format should I send someone?
PDF, unless they've explicitly asked to edit it. If they need to edit, send the format their software uses — DOCX for a Microsoft shop, ODT for a LibreOffice one. Sending an editable format "just in case" is how layouts get broken.
Is ODT better than DOCX?
Better on openness, worse on ubiquity. ODT is a genuine open standard with no vendor behind it; DOCX is what the world actually uses. For interoperable delivery, neither wins — PDF does.
Why does my document look different when someone else opens it?
Because these formats describe the document and let the reader's software render it. If they don't have your font, it substitutes one; if their version handles a layout feature differently, it reflows. PDF avoids this by embedding the fonts and fixing the layout at export time.
Can I convert a PDF back to an editable format?
Yes, though it's a reconstruction rather than a perfect round-trip — see PDF to Word. Keep your original editable file as the source of truth; treat the PDF as the published version.
What about plain text (TXT)?
That's the fourth cousin — no formatting at all, maximum compatibility. It's covered in our TXT to PDF guide, and it's the right choice when the content is code, logs, or notes rather than a formatted document.
Wrap-up
- DOCX — the Microsoft standard. Ubiquitous, feature-rich, still renders differently across programs.
- ODT — the open standard. Principled, mandated in the public sector, and frequently unopenable by the person you sent it to.
- RTF — the ancient compromise. Opens almost anywhere, capable of almost nothing modern.
All three are formats for writing. When it's time to send the document, convert it to PDF — that's the format built for delivery, and the only one that guarantees your recipient sees what you saw.