APA vs MLA vs Chicago Title Case: Which Words to Capitalize in Each Style

Title case looks simple until you have to follow a style guide. Should "through" be capitalized? What about "after" or "the"? The answer depends on whether you are writing in APA, MLA, or Chicago style — and the three guides disagree more often than most students expect.

This guide compares the three styles side by side, so you can check your title against the right rule instead of guessing. For the general question of which words get capitalized in any title, our guide on which words do you capitalize in a title covers the basics first.

The One Rule All Three Styles Share

Every style agrees on this: always capitalize the first and last word of a title, no matter what kind of word it is. "The" is capitalized at the start of a title, and a preposition is capitalized if it happens to be the last word.

Beyond that, the styles split on the small words in the middle: articles (a, an, the), short prepositions (in, on, at, of, to), and short conjunctions (and, but, or, nor, for, so, yet).

APA Title Case Rules

APA (American Psychological Association) style is used in psychology, education, and much of the social sciences. Its title case rule is:

• Capitalize the first word of the title and of any subtitle.
• Capitalize all major words: nouns, verbs, adjectives, adverbs, and pronouns.
• Capitalize words of four or more letters, including prepositions of four or more letters.
• Lowercase articles (a, an, the), prepositions of three or fewer letters (in, on, at, of, to), and conjunctions of three or fewer letters (and, but, or).

The four-letter cut-off is APA’s signature quirk. A preposition like "through" (seven letters) is capitalized in APA, while "in" (two letters) is not.

MLA Title Case Rules

MLA (Modern Language Association) style is used in literature, languages, and the humanities. Its rule is simpler:

• Capitalize the first and last word of the title.
• Capitalize all principal words: nouns, pronouns, verbs, adjectives, and adverbs.
• Lowercase articles, prepositions, and coordinating conjunctions, regardless of length, unless they are the first or last word.

MLA has no four-letter exception. A long preposition like "through" stays lowercase in the middle of an MLA title, which is the biggest visible difference from APA.

Chicago Title Case Rules

Chicago (The Chicago Manual of Style) is used in history, publishing, and much of book writing. Its rule is close to MLA:

• Capitalize the first and last word of the title.
• Capitalize all major words: nouns, pronouns, verbs, adjectives, and adverbs.
• Lowercase articles, prepositions (regardless of length), and coordinating conjunctions, unless they are the first or last word.
• One exception: a preposition is capitalized when it is used as an adverb or adjective rather than as a preposition — for example, "off" in "The Rocket Takes Off" is capitalized because it describes how the rocket moves, not a direction.

For most titles, Chicago and MLA give the same answer. The differences show up in edge cases like adverbial prepositions and hyphenated words.

Side-by-Side Comparison

Title	APA	MLA	Chicago
The Old Man and the Sea	The Old Man and the Sea	The Old Man and the Sea	The Old Man and the Sea
Running Through the Forest	Running Through the Forest	Running through the Forest	Running through the Forest
What to Do After the Storm	What to Do After the Storm	What to Do after the Storm	What to Do after the Storm
A Study of Birds in the Wild	A Study of Birds in the Wild	A Study of Birds in the Wild	A Study of Birds in the Wild
Morse Code: A Beginner’s Guide	Morse Code: A Beginner’s Guide	Morse Code: A Beginner’s Guide	Morse Code: A Beginner’s Guide

Look at the second row: "through" is capitalized in APA because it has more than three letters, but lowercase in MLA and Chicago because both styles lowercase all prepositions. The third row shows the same split with "after". The last row shows the subtitle rule all three styles share: the first word after a colon is always capitalized, which is why "A" is capitalized there even though it is an article.

Tricky Words, Decided

• Through, between, among, after, before, under, over: capitalized in APA (four or more letters), lowercase in MLA and Chicago.
• In, on, at, of, to, by, up: lowercase in all three styles when they sit in the middle of a title.
• And, but, or, nor, for, so, yet: lowercase in all three styles when they sit in the middle of a title.
• The first word after a colon: capitalized in all three styles. "Morse Code: A Beginner’s Guide" is correct everywhere.
• The last word: capitalized in all three styles, even if it is a preposition. "What Are You Waiting For" ends with "For" capitalized in every style.
• Hyphenated words: capitalize both parts if both are major words (for example, "Well-Known Facts"). If the second part is a small word, styles differ slightly — when in doubt, check your style guide’s hyphenation rule for that exact word.

Which Style Should You Use?

You usually do not get to choose: your teacher, university, or publisher tells you. If nobody has specified a style, pick one and use it consistently — mixing styles in the same paper is the real mistake.

Frequently Asked Questions

Is "through" capitalized in a title?

In APA, yes — "through" has more than three letters, so APA capitalizes it. In MLA and Chicago, no — both styles lowercase all prepositions in the middle of a title. "Running Through the Forest" (APA) becomes "Running through the Forest" (MLA and Chicago).

Do APA, MLA, and Chicago capitalize the same words?

Mostly, but not always. All three capitalize the first and last words and all major words. They differ on prepositions of four or more letters, which APA capitalizes and MLA and Chicago lowercase.

Is "the" capitalized in the middle of a title?

No. "The" is an article, and all three styles lowercase articles in the middle of a title. It is only capitalized when it is the first or last word.

What is capitalized after a colon in a title?

The first word of the subtitle is capitalized in all three styles, even if it is a small word like "a" or "the". For example: "Morse Code: A Beginner’s Guide".

The Short Version

If you remember one thing, make it this: APA cares about word length, MLA and Chicago do not. A preposition of four or more letters — through, after, between — is capitalized in APA and lowercase in the other two. Everything else is mostly agreement. Check your style, fix the small words, and try our free case converter for the first pass.

And if you are torn between the two styles themselves, see sentence case vs title case for a side-by-side comparison with examples.