Title Case Rules: AP, APA, Chicago and MLA Compared
Writing & text · October 17, 2026 · 2 min read
Title case means capitalizing the important words in a title and leaving the small ones in lowercase. Every style guide agrees on the idea and then disagrees about where to draw the line. Knowing the differences saves you from rewriting headlines.
What every style agrees on
- Capitalize the first word and the last word, even if they are small words.
- Capitalize the first word after a colon, which starts the subtitle.
- Capitalize nouns, verbs, adjectives, adverbs and pronouns.
- Lowercase the short articles a, an and the, and short conjunctions like and, but and or.
AP and APA: the length rule
AP and APA lowercase articles, short conjunctions and short prepositions of three letters or fewer, such as in, of, on and for. Longer words stay capitalized, including prepositions like Between and Through. So you write A Walk Between Two Worlds.
Chicago and MLA: the preposition rule
Chicago and MLA lowercase every preposition, however long, along with articles and coordinating conjunctions, and the word to. The same title becomes A Walk between Two Worlds. The test is the type of word, not its length.
Hyphens and special cases
- In a hyphenated word, capitalize each major part: Well-Known, Self-Driving. A small part after a hyphen can stay lowercase, as in Built-in.
- Leave names and brands as they are written, such as iPhone and NASA.
- Lowercase the word to in an infinitive, as in Something to Be Proud Of in Chicago style.
Titles in a reference list are different
APA writes the titles of books and articles in sentence case in the reference list, with only the first word and proper nouns capitalized, and uses title case in the body of the paper. MLA and Chicago use title case in their lists. The Citation Generator keeps whatever capital letters you type, so enter titles in the form your style expects.
Use the tool
Paste your headline into the Title Case Converter and choose AP and APA, Chicago and MLA, or every word. For simple all-caps or sentence case changes, the Case Converter is quicker. Always check unusual titles against your own style guide.