Case Converter
This free case converter changes the capitalization of your text in one click, across 15 styles. It does proper Title Case following AP or Chicago rules, plus UPPERCASE, lowercase, Sentence case, and code styles like camelCase and snake_case. Everything runs in your browser and nothing is uploaded.
THE LORD OF THE RINGS: THE RETURN OF THE KING
How do you change text case online?
Paste the text, pick a style, copy the result. There are 15 styles, from UPPERCASE and lowercase to Title Case that follows the AP or the Chicago rules, plus every identifier style a developer needs. The result updates as you type, keeps your line breaks, and your text never leaves your browser.
What we tested
| You type | Style | What comes out |
|---|---|---|
| gone with the wind | Title Case (AP) | Gone With the Wind |
| gone with the wind | Title Case (Chicago) | Gone with the Wind |
| the lord of the rings: the return of the king | Title Case (AP) | The Lord of the Rings: The Return of the King |
| how NASA uses AI on the iPhone | Title Case (AP) | How NASA Uses AI on the iPhone |
| state-of-the-art design for what it is worth | Title Case (AP) | State-of-the-Art Design for What It Is Worth |
| HELLO WORLD FROM CAPS LOCK | Sentence case | Hello world from caps lock |
| XMLHttpRequest handler v2 | camelCase | xmlHttpRequestHandlerV2 |
| XMLHttpRequest handler v2 | CONSTANT_CASE | XML_HTTP_REQUEST_HANDLER_V2 |
What is the difference between Title Case and Capitalized Case?
It matters if you write headlines.
Capitalized Case capitalizes every single word, including "a", "of" and "the". It is simple and predictable, and it is what many people mean when they say "title case".
Title Case follows an actual style guide: small words stay lowercase unless they are the first word, the last word, or the word right after a colon. That is what editors, journalists and academics mean by the term.
Both are here, named honestly, so you can pick the one you actually want.
AP or Chicago: which should you choose?
They agree on almost everything and disagree about prepositions.
| Title | AP | Chicago |
|---|---|---|
| gone with the wind | Gone With the Wind | Gone with the Wind |
| the fox jumps over the dog | ...Jumps Over the Dog | ...Jumps over the Dog |
AP lowercases prepositions of three letters or fewer, so longer ones like "With", "Over" and "From" stay capitalized. It is common in journalism, marketing and web copy.
Chicago lowercases prepositions regardless of length. It is common in books and academic writing.
Both capitalize the first and last word no matter what, and both capitalize the word after a colon, so a subtitle starts cleanly.
A fair warning: style guides have genuine edge cases, from phrasal verbs ("Look Up" in Chicago) to words that work as both preposition and adverb. No automatic rule resolves all of them, so treat the result as a fast, consistent first pass and read the headline once.
What are the programming styles for?
Identifier styles strip punctuation and rebuild your words as a single token, because that is what a variable or a key has to be.
- camelCase for JavaScript variables and functions:
userFirstName - PascalCase for classes and React components:
UserProfileCard - snake_case for Python and SQL columns:
user_first_name - kebab-case for URLs, CSS classes and file names:
user-first-name - CONSTANT_CASE for environment variables and constants:
MAX_RETRY_COUNT - dot.case for config keys and feature flags:
feature.new.checkout - Train-Case for HTTP headers:
Content-Type,Accept-Language
The converter also understands existing camelCase and PascalCase boundaries, so you can go from one identifier style straight to another without breaking the words apart by hand.
What about tOGGLE and aLtErNaTiNg?
tOGGLE cASE flips whatever case each letter already has. It is the repair tool for a paragraph typed with Caps Lock on by mistake, where the sentence came out inverted.
aLtErNaTiNg alternates up and down as it goes, regardless of the original. It is used for a sarcastic tone online and, occasionally, to make a label deliberately hard to read.
Does it keep line breaks, punctuation and acronyms?
Yes for every style that only changes capitalization, including Sentence case, which treats each new line as the start of a sentence. That matters for lists and multi-line text, where a naive converter leaves every line after the first in lowercase.
Acronyms and brand names survive too. "how NASA uses AI on the iPhone" becomes "How NASA Uses AI on the iPhone" in Title Case, not "Nasa" and "Iphone", and Sentence case writes a lone "i" as "I".
The identifier styles are the deliberate exception: they collapse everything into one token and drop punctuation, because an identifier cannot contain spaces or commas.
To count what you wrote, the word counter is one click away; to turn a title into a web address, use slugify.
Frequently asked questions
What is Title Case and how is it different from Sentence case?
Title Case capitalizes the main words of a title and keeps small words such as a, of and the lowercase unless they come first or last, as in 'The Lord of the Rings'. Sentence case capitalizes only the first word of each sentence, like normal prose: 'The lord of the rings'. To capitalize every word, pick Capitalized Case.
What are camelCase, snake_case, and kebab-case for?
These are naming styles used in programming. camelCase joins words with each new word capitalized, like myVariableName. snake_case joins them with underscores, like my_variable_name. kebab-case uses hyphens, like my-variable-name. Developers pick one to match the language or project style they are working in.
Does converting to a code style remove my punctuation?
Yes, for the programming styles. camelCase, PascalCase, snake_case, kebab-case, and CONSTANT_CASE turn your text into a single identifier, so spaces and punctuation become separators or are removed. The plain styles, like UPPERCASE and Title Case, keep your punctuation and spacing exactly as they were.
Is my text sent to a server?
No. The case converter runs entirely in your browser with JavaScript. The text you paste is never uploaded, logged, or stored, and it disappears when you close or refresh the tab. You can convert private or sensitive text safely, and it works offline once the page has loaded.
How does Title Case handle small words like 'a' and 'the'?
That is exactly what the AP and Chicago options are for: both keep articles, conjunctions and short prepositions lowercase, unless the word is first, last, or follows a colon. If you would rather capitalize every single word, pick Capitalized Case instead, which is the simple rule.
What is the difference between AP and Chicago title case?
They disagree about prepositions. AP lowercases only those of three letters or fewer, so it writes "Gone With the Wind". Chicago lowercases prepositions regardless of length, giving "Gone with the Wind". Both capitalize the first and last word, and both lift the word after a colon.
What is tOGGLE cASE?
It flips the case of every letter: capitals become lowercase and lowercase becomes capitals. It is the fix for text typed with Caps Lock on by accident, where the first letter of each sentence came out small and everything else came out shouting.
What are dot.case and Train-Case for?
Both are identifier styles. dot.case joins lowercase words with periods and shows up in config keys and feature flags, such as feature.new.checkout. Train-Case capitalizes each word and joins with hyphens, which is the shape of HTTP headers like Content-Type and Accept-Language.
Does it keep acronyms like NASA and brand names like iPhone?
Yes. In Title Case, Sentence case and Capitalized Case, a word typed in capitals, such as NASA, AI or U.S., or with a capital inside it, such as iPhone or YouTube, stays as you typed it, and a lone i becomes I. Text typed entirely in capitals is the exception, so it can still be converted.
Which case should I use for a headline?
Follow whichever guide your publication uses: AP is common in journalism and marketing, Chicago in books and academia. If you have no house style, pick one and stay consistent, because mixed capitalization across headings is far more noticeable to a reader than the choice itself.
Related tools
Rate Case Converter & help shape it
This tool is free and still growing. Tell us what works, what you would change, and what is missing. Your feedback is what decides what we build next.
Built and tested by the ÆON Toolhub team. Last updated: October 19, 2026. How we test our tools