What Is Title Case? Rules, Examples, and Style Guides | TitleCasePro

Title case is a capitalization style where the first letter of major words in a heading or title is uppercase, while minor words remain lowercase. It is the standard for book titles, article headlines, chapter headings, and formal document titles across most English-language publications.

Understanding title case matters because different audiences expect different conventions. A research paper submitted in the wrong capitalization style looks unprofessional. A blog headline that ignores title case reads as careless. And a developer who doesn’t know the difference between camelCase and PascalCase will write code that breaks naming conventions.

Which Words Are Capitalized in Title Case

The basic principle is that principal words get capitalized and minor words stay lowercase — unless they appear at the very start or end of the title, where all words are always capitalized regardless of category.

Always capitalize:

• Nouns — Book, Mountain, Theory
• Verbs — Write, Is, Runs
• Adjectives — Beautiful, Long, Critical
• Adverbs — Quickly, Always, Never
• The first and last word of any title, no matter what part of speech

Usually lowercase (when in the middle of a title):

• Articles: a, an, the
• Short prepositions: at, by, for, in, of, on, to, up
• Coordinating conjunctions: and, but, for, nor, or, so, yet

⚠️ Universal rule: The first and last word of any title are always capitalized — even if they are articles, prepositions, or conjunctions.

Why There Is No Single Title Case Standard

Here is where it gets complicated: different style guides define title case differently. The four most widely used style guides — APA, Chicago, AP, and MLA — each have slightly different rules for prepositions, conjunctions, and articles.

• APA lowercases all prepositions regardless of length. Through and between stay lowercase even though they are long words.
• Chicago takes a length-based approach: prepositions of four letters or fewer are lowercase, but longer ones like About, Between, Through are capitalized.
• AP (used by journalists) capitalizes any word that is four or more letters — a simple rule easy to apply on deadline.
• MLA is similar to APA: all prepositions stay lowercase regardless of length.

The same title formatted across four styles:

Style	Result
APA	A Guide to Writing about the Environment
Chicago	A Guide to Writing About the Environment
AP	A Guide to Writing About the Environment
AMA	A Guide To Writing About The Environment

Note: AMA (American Medical Association) capitalizes every single word — including articles, prepositions, and conjunctions — making it the most distinctive style.

Use the style comparison tool to see any title across all nine style guides at once.

Title Case vs. Sentence Case

Sentence case is the other common capitalization style. Only the first word of the title and any proper nouns are capitalized — everything else stays lowercase.

Title case: How to Write a Great Research Paper About Climate Change Sentence case: How to write a great research paper about climate change

Context	Preferred style
Academic papers	Title case (APA/Chicago/MLA)
News headlines	Title case (AP)
Wikipedia articles	Sentence case
Email subject lines	Sentence case
Blog posts	Either (pick one, be consistent)
Legal documents	Title case (Bluebook)

Common Title Case Mistakes

Capitalizing every word

“The Quick Brown Fox Jumps Over The Lazy Dog” — This is called Start Case or All Words Caps, not title case. True title case lowercases minor words like Over and The in the middle.

Lowercasing verbs

“How to write better” should be “How to Write Better” — Verbs like write, run, be, is, are are always capitalized in title case.

Forgetting “is” is a verb

Many people accidentally lowercase is because it’s short. But is is a linking verb and gets capitalized in all title case styles.

⚠️ Common mistake: “Why sleep is important” is wrong. The correct form is “Why Sleep Is Important” — both Sleep (noun) and Is (verb) must be capitalized.

Lowercasing the last word

The last word of a title is always capitalized, even if it’s a, an, the, in, or of.

Title Case for Different Content Types

Content type	Standard
Academic papers	APA, Chicago, or MLA (check your institution)
Newspaper / magazine articles	AP style
Books	Chicago style
Blog post headings	AP, Chicago, or sentence case
Email subject lines	Sentence case
SEO title tags	Title case (better readability in SERPs)

Summary

Key takeaway: Title case capitalizes principal words (nouns, verbs, adjectives, adverbs) and lowercases minor words (articles, short prepositions, coordinating conjunctions), except at the start and end of a title where all words are capitalized. Different style guides — APA, Chicago, AP, MLA, Bluebook, AMA, NY Times, Wikipedia — each define slightly different rules for which words count as “minor.”

Use the title capitalizer to get the correct result for any style in seconds, with a word-by-word explanation of every rule applied. For side-by-side comparison of all nine styles, use the compare tool.