Case Converter
Paste your text, then click a case style below to convert it, UPPERCASE, lowercase, Title Case, camelCase and more.
About the Case Converter
Quick Answer: The Case Converter is a free online tool that changes text between twelve common capitalization formats including UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, Capitalized Case, alternating case, and inverse case. Conversions run client-side with zero latency and full privacy.
Twelve versatile case styles are available at once, from a simple UPPERCASE or lowercase flip to programming-friendly formats like camelCase, snake_case, and CONSTANT_CASE for turning a plain phrase into a valid variable name. Title Case keeps small words like "a", "the" and "of" lowercase unless they open the sentence, matching typical headline style. Every conversion runs instantly against whatever is typed or pasted in, with the original left untouched in the input box so switching between case styles never means retyping the source text.
- Title Case: Capitalizes each word, keeping common short words like "a", "the" and "of" lowercase unless they start the text.
- camelCase / PascalCase / snake_case / kebab-case: Splits the text into words and rejoins them in the programming naming style chosen.
- CONSTANT_CASE / Capitalized Case / InVeRsE cAsE: Provides specialized capitalization for software developers, publishers, and copywriters.
- Live Metrics: Tracks characters, words, and line count dynamically as you type.
Capitalization Conventions Reference
| Format Name | Primary Application | Delimiter Rule | Example Transformation |
|---|---|---|---|
| UPPERCASE | SQL keywords, constants, alert headlines | Preserves existing spaces | hello world → HELLO WORLD |
| lowercase | URL paths, search tags, email normalization | Preserves existing spaces | Hello World → hello world |
| Title Case | Article headings, book titles, UI buttons | Capitalizes major words | the lord of the rings → The Lord of the Rings |
| Sentence case | Document prose, paragraphs, descriptions | Capitalizes after punctuation (.!?) | hello world. how are you? → Hello world. How are you? |
| camelCase | JavaScript, Java, Swift variables/methods | No spaces; capitalized inner words | user account profile → userAccountProfile |
| PascalCase | React components, TypeScript classes, C# | No spaces; capitalized first letters | user account profile → UserAccountProfile |
| snake_case | Python, SQL tables/columns, Rust | Underscore delimiter | user account profile → user_account_profile |
| kebab-case | CSS class names, URL slugs, HTML attributes | Hyphen delimiter | user account profile → user-account-profile |
| CONSTANT_CASE | Environment variables, C/Java constants | Underscore delimiter with uppercase | server config port → SERVER_CONFIG_PORT |
| Capitalized Case | Person names, postal addresses, tabular headers | Capitalizes every word unconditionally | the lord of the rings → The Lord Of The Rings |
| aLtErNaTiNg | Social media memes, sarcastic expressions | Alternating letter cases | hello world → hElLo wOrLd |
| InVeRsE cAsE | Typo recovery (Caps Lock on), aesthetic text | Flips character casing | Hello World → hELLO wORLD |
Which naming style fits which context
The programming-style converters are tailored for specific language idioms. camelCase is standard for variable and function names in JavaScript and Java. PascalCase is standard for class and component names, including TypeScript interfaces and React components. snake_case is standard for variables and functions in Python, database table columns, and configuration keys. kebab-case is idiomatic in URL slugs and CSS class selectors where underscores or capital letters are avoided. CONSTANT_CASE is essential for defining immutable globals, environment keys (such as API_SECRET_KEY), and configuration enumerations.
Title Case Rules: AP vs. Chicago Manual of Style
Title capitalization differs across major editorial stylebooks. The Associated Press (AP) style capitalizes words of four or more letters (including words like "With" or "Over"), whereas the Chicago Manual of Style lowercases prepositions regardless of length unless they open or close the title. Our Title Case converter follows established headline conventions, preserving lowercase formatting for common short conjunctions and prepositions (a, an, the, and, but, or, for, nor, of, to, in, at, on, by) while capitalizing all core verbs, nouns, and adjectives.
SEO and URL Slugs: Why kebab-case Dominates Google Rankings
When structuring URLs for search engine optimization, Google's developer guidelines explicitly recommend hyphens (-) rather than underscores (_) as word delimiters. Search engine web crawlers treat hyphens as clean spaces, allowing them to index individual keywords correctly. For instance, utility369.com/text-tools/case-converter is parsed as "text tools case converter", whereas an underscore delimited URL like case_converter can be processed as an unseparated single compound token. If you need to generate clean, URL-ready permalinks with accent stripping and punctuation removal, check out our specialized Text to Slug generator.
Sentence case handling
Sentence case lowercases the entire input first, then capitalizes only the very first letter and any letter immediately following a period, exclamation mark, or question mark plus whitespace. An acronym or proper noun like "NASA" or "London" gets lowercased unless it starts a sentence, so an editorial review pass is helpful for text with proper names.
Frequently Asked Questions
Which case style should I use for a JavaScript variable name?
camelCase is the standard convention for variables and function names in JavaScript. PascalCase is used for class and component names instead, while snake_case and kebab-case are not idiomatic JavaScript naming conventions.
Why did sentence case lowercase an acronym like NASA?
Sentence case lowercases the entire text first, then capitalizes only the first letter of each sentence. An acronym or proper noun gets lowercased along with other words unless it happens to start a sentence, requiring manual verification.
Does Title Case always capitalize the last word, even a small one?
This converter capitalizes the first word and any word not in its small-words list (like a, the, of). Style guides that mandate capitalizing the final word regardless of length can be accommodated by checking the output.
How are numbers handled in camelCase or snake_case conversion?
A run of digits is treated as its own word segment. A decimal number splits at the period into separate segments, so 2.5 becomes 2 and 5 rather than staying together.
What is alternating case actually used for?
Alternating case is commonly used to convey a sarcastic or mocking tone in online messages, meme captions, or social media posts. It alternates uppercase and lowercase characters across letters.
Is my text sent to a server when I use this tool?
No. All text conversions execute 100% locally in your web browser with zero server requests or storage.
What is CONSTANT_CASE and when is it used?
CONSTANT_CASE (also known as SCREAMING_SNAKE_CASE) uses all uppercase letters with underscores separating words. It is universally used in programming languages like C, Java, Python, and JavaScript to define constant variables and environment flags.
How does Capitalized Case differ from Title Case?
Capitalized Case capitalizes the first letter of every single word indiscriminately. Title Case follows grammatical stylebook rules (such as Chicago or AP style) by keeping short conjunctions, articles, and prepositions like of, the, in, and and lowercase unless they appear at the beginning of a title.
Can this case converter preserve accents, diacritics, and international characters?
Yes. Modern JavaScript string methods preserve Unicode diacritics and accented characters across Spanish, French, German, and other international languages without corrupting glyphs.
What is kebab-case best used for?
kebab-case (hyphen-separated lowercase words) is the global standard for web URL slugs, CSS class names, HTML attributes, and RESTful API endpoints because search engines recognize hyphens as word delimiters.