Case Conversion Examples: Same Phrase, Different Rules

“the lord of the rings” is not one result. Sentence case returns The lord of the rings. Title case returns The Lord of the Rings. Capitalized case returns The Lord Of The Rings. Those three strings came from the converters on this site, not from a style manual. The rest of this page is the same kind of check: input, rule, and the exact output.

One phrase, ten results

the lord of the rings
sentence      The lord of the rings
title         The Lord of the Rings
capitalized   The Lord Of The Rings
camelCase     theLordOfTheRings
PascalCase    TheLordOfTheRings
snake_case    the_lord_of_the_rings
kebab-case    the-lord-of-the-rings
dot.case      the.lord.of.the.rings
URL slug      the-lord-of-the-rings

Sentence case and title case disagree on “Lord” and “Rings.” Title case and capitalized case disagree on “Of.” The slug and the kebab-case string match here only because the input was already separate lowercase words. They stop matching as soon as the input contains camelCase, accents, or punctuation.

The title-case small-word list

In the middle of a heading, title case lowercases only these words: a, an, the, and, but, or, for, nor, on, at, to, by, in, of, as, is, if, vs, via. The first word and the last word are capitalized even if they are on that list. Every other word gets a capital on its first character after the whole word has been lowercased.

• the lord of the rings → The Lord of the Rings
• this is a test → This is a Test (“is” and “a” are on the list; the last word is still capped)
• to be or not to be → To Be or Not to Be (“or” and the inner “to” stay lower; “be” is not on the list)
• cats vs dogs → Cats vs Dogs
• a guide from the editor → A Guide From the Editor (“from” is not on the list; “the” is)
• with or without you → With or Without You
• the end → The End

This is not APA, MLA, or Chicago. APA often capitalizes words of four letters or more, so “from” and “with” would be capped there too — which happens to match this list — but “over,” “into,” and “than” are also capped here, and a university style check can still disagree. “is” and “vs” staying lowercase is a CaseSwitch choice, not a Chicago rule.

Hyphens: one word in title case, several in capitalized case

Title case cuts the line on whitespace only. “well-known” is one token, so only the “w” is eligible for a capital. Capitalized case uses a word boundary, and a hyphen is a boundary, so the letter after the hyphen is capitalized too.

well-known author
title         Well-known Author
capitalized   Well-Known Author

state-of-the-art design
title         State-of-the-art Design
capitalized   State-Of-The-Art Design

Word’s Capitalize Each Word, Google Docs’ Title case, and Excel’s PROPER follow the capitalized-case pattern. If a heading style wants “Well-Known” rather than “Well-known,” title case on this site will not produce it. If it wants “State-of-the-art” rather than “State-Of-The-Art,” capitalized case will not produce that either.

Periods only start a sentence when a space follows

Sentence case lowercases the entire string first, then capitalizes the first letter and any letter that comes after a period, exclamation mark, or question mark plus whitespace. A period with no space does not count. That is why initials and degrees lose their internal capitals, and why an ellipsis followed by a space starts a new sentence.

• U.S. army arrived today. → sentence “U.s. Army arrived today.” Title case: “U.s. Army Arrived Today.” Capitalized case: “U.S. Army Arrived Today.”
• Ph.D. students left. → sentence “Ph.d. Students left.” The “S” in Students is capped because a space follows that period. The “d” is not, because “Ph.d” has no space.
• e.g. this is a note → “E.g. This is a note.”
• hello... world → “Hello... World” in sentence case. The space after the third dot is enough.
• Dr. Smith arrived. he left. → “Dr. Smith arrived. He left.”

A newline is not a sentence boundary. “hello” then a line break then “world. next” becomes “Hello” at the start of the first line and leaves “world” lowercase until the period-space before “Next.”

Brands and acronyms are lowercased first

Sentence case, title case, and capitalized case all lowercase the text before they put capitals back. A capital that was in the middle of a word does not survive.

• iPhone vs eBay → sentence “Iphone vs ebay.” Title: “Iphone vs Ebay.”
• NASA launched a rocket. → “Nasa launched a rocket.” Title: “Nasa Launched a Rocket.”
• HTML and CSS guide → title “Html and Css Guide.” “and” stays lower because it is on the small-word list. “HTML” does not stay “HTML.”
• McDonald's → title “Mcdonald's.” Capitalized case: “Mcdonald'S,” because the apostrophe is a word boundary and the “s” is treated as a new word.
• Q3 results for 2026 → sentence “Q3 results for 2026.” The “3” keeps the token looking like “Q3” after the first letter is capped. Title: “Q3 Results for 2026.”

camelCase splits. A slug does not.

camelCase, PascalCase, snake_case, kebab-case, and dot.case share one splitter. It breaks on spaces, underscores, hyphens, and dots. It also breaks between a lowercase letter or digit and an uppercase letter, and between an acronym and a following word (“XML” + “Http”). Each piece is then lowercased and rejoined.

userProfileId
camelCase     userProfileId
kebab-case    user-profile-id
URL slug      userprofileid

XMLHttpRequest
camelCase     xmlHttpRequest
PascalCase    XmlHttpRequest
kebab-case    xml-http-request
URL slug      xmlhttprequest

getHTTPResponse
camelCase     getHttpResponse
kebab-case    get-http-response

iPhone vs eBay
kebab-case    i-phone-vs-e-bay
URL slug      iphone-vs-ebay

Café au lait
kebab-case    café-au-lait
URL slug      cafe-au-lait

hello, world
kebab-case    hello,-world
URL slug      hello-world

Use the slug generator for a public URL. It strips accents, turns apostrophes into separators (“McDonald's” → “mcdonald-s”), and drops punctuation. Use kebab-case when the source is an identifier such as userProfileId and you want the words split. Do not send a title full of commas through kebab-case and publish the comma.

Identifiers: kebab-case Converter. Public paths:

Slug Generator.

Fix these by hand

• Product names: iPhone, eBay, GitHub, macOS. Every prose case style will damage them.
• Acronyms: NASA, HTML, CSS, API. They become Nasa, Html, Css, Api.
• Initials and degrees: U.S., Ph.D., i.e. Sentence case and title case only keep the first letter.
• Hyphenated compounds when you need a capital after the hyphen. Title case will not add it.
• Apostrophes in names. Capitalized case will capitalize the letter after the apostrophe.
• camelCase pasted into a slug. The words will be glued together.

Run a heading through the Title Case Converter or a paragraph through the

Sentence Case Converter, then correct the names before you publish. The menu-by-menu version of this, for Word, Docs, Excel, and VS Code, is in

how to change text case in those apps.

Questions people ask

Why does title case leave “of” lowercase but capitalize “from”?

Title case on CaseSwitch lowercases only this list in the middle of a heading: a, an, the, and, but, or, for, nor, on, at, to, by, in, of, as, is, if, vs, via. “from” and “with” are not on it, so “a guide from the editor” becomes “A Guide From the Editor.” The first and last words are capitalized even when they are on the list, which is why “the end” becomes “The End.”

Why does “well-known” stay “Well-known” in title case?

Title case treats everything up to the next space as one word, so the hyphen never starts a new capital: “well-known author” becomes “Well-known Author.” Capitalized case uses a word boundary at the hyphen, so the same input becomes “Well-Known Author.” Excel PROPER and Word’s Capitalize Each Word behave like capitalized case, not like this title case.

Why does a slug turn iPhone into iphone while kebab-case turns it into i-phone?

The slug generator lowercases the text and replaces anything that is not a letter or digit with a hyphen. It does not split camelCase, and it strips accents. kebab-case splits on a change from a lowercase letter to an uppercase letter, so “iPhone” becomes “i-phone” and “userProfileId” becomes “user-profile-id.” The slug of “userProfileId” is “userprofileid.”