Title case rules by style guide
| Style | Lowercase (unless first or last) | Example |
|---|---|---|
| APA (7th ed.) | Articles, and conjunctions and prepositions of three letters or fewer. Words of four or more letters are capitalized. | A Guide to Writing With Confidence |
| Chicago (CMOS) | Articles; all prepositions, whatever their length; and, but, for, or, nor; “to” in infinitives; “as”. | A Guide to Writing with Confidence |
| AP style | Articles, and conjunctions and prepositions of three letters or fewer. | A Guide to Writing With Confidence |
| MLA (9th ed.) | Articles, all prepositions, coordinating conjunctions and “to” in infinitives. | A Guide to Writing with Confidence |
Rules every style shares
- Capitalize the first and the last word of the title.
- Capitalize the first word after a colon (the start of a subtitle).
- Capitalize nouns, pronouns, verbs (including short ones such as “Is” and “Be”), adjectives and adverbs.
- In hyphenated compounds, capitalize both parts when both are major words: “Long-Term Plan”.
- Keep acronyms and brand spellings as written: NASA, iPhone, eBay.
Where the styles really disagree
Almost every difference comes down to prepositions of four letters or more, such as “with”, “from”, “into”, “over” and “about”. APA and AP capitalize them; Chicago and MLA keep them lowercase. If your title has none of these words, all four styles usually agree.
Words that can be prepositions or adverbs (“up” in “Set Up Your Account”) are a judgement call: style guides capitalize them when they work as part of a phrasal verb. The converter treats them as prepositions, so check phrasal verbs by eye.
Title case or sentence case?
APA uses title case for the titles of papers and for headings, but sentence case for the titles of works in a reference list. Many news sites and style guides such as the GOV.UK style guide use sentence case for headlines. Whichever you choose, use it consistently.