Capitalization looks trivial until you’re staring at a heading wondering which words to capitalize. Here are the common styles, when each fits, and how to switch between them instantly.
The main styles
- Title Case — Capitalize The Major Words (nouns, verbs, adjectives), lowercase short words like a, the, of, and. Used for titles and headlines, especially in US editorial styles.
- Sentence case — Only the first word and proper nouns are capitalized. Increasingly the default for headings and UI because it reads naturally and is easier to get consistent.
- UPPERCASE — All caps. For short labels, acronyms or emphasis — but hard to read in long runs.
- lowercase — All small. A deliberate stylistic choice for a casual, modern tone.
Which should you use?
- Blog/article titles: Title Case (traditional) or Sentence case (modern, cleaner). Pick one and be consistent site-wide.
- UI labels, buttons, form fields: Sentence case — it’s friendlier and easier to maintain.
- Navigation, tags: Title Case or sentence case; avoid ALL CAPS for anything long.
The golden rule is consistency: pick a style per context and apply it everywhere.
Watch out for
- Proper nouns always keep their capitals (iPhone, GitHub, Taiwan).
- Title-case rules vary by style guide (AP vs Chicago) on which small words to capitalize — automated title case gets you 95% there; eyeball the rest.
Convert in one click
- Case converter — switch text between Title Case, Sentence case, UPPERCASE and lowercase instantly, in your browser.
- Counting words or characters for a headline limit? Word counter.
Pick a style, run it through the converter, and your headings and labels stay clean and consistent.
AP vs Chicago: the small-word rules
Both capitalize the important words; they disagree on the little ones.
- AP style capitalizes any word of four letters or more, including prepositions like Over, With and From. It lowercases short articles, conjunctions and prepositions (a, an, the, and, but, or, for, nor, to).
- Chicago style lowercases all prepositions regardless of length, plus articles and coordinating conjunctions. So a four-letter preposition stays small.
The classic tell is a word like over:
AP: The Cat Jumps Over the Wall
Chicago: The Cat Jumps over the Wall
Both always capitalize the first and last word of the title, no matter what.
The other “cases” — in code
In programming, “case” describes how you join words in an identifier, and each ecosystem has a favorite:
camelCase— variables and functions (JavaScript, Java)PascalCase— classes, types, React componentssnake_case— Python variables, database columnskebab-case— URLs, CSS classes, file namesSCREAMING_SNAKE_CASE— constants
These aren’t style preferences like prose casing — mixing them up can break code. See naming conventions in code for when to use each.
Quick reference
| Where | Use |
|---|---|
| Blog/article title | Title Case or Sentence case (pick one) |
| Section subheads | Sentence case |
| Buttons, form labels | Sentence case |
| Nav items, tags | Title Case or Sentence case |
| Code identifiers | camelCase / snake_case, per language |
FAQ
Is title case wrong now?
No — it’s still standard in US publications and many blogs. Sentence case is simply more common in product UI, where it feels friendlier and is easier to keep consistent.
What do big tech sites use?
Apple, Google and most modern design systems default to sentence case for headings and interface text. It reduces the “which word gets a capital?” guesswork.