Case Converter
Convert text between 16 case formats simultaneously — camelCase, snake_case, kebab-case, PascalCase, Title Case, and more. Real-time conversion, text stats, favorites, and cleanup tools. 100% private — nothing leaves your browser.
How to convert text case
Type or paste any text into the input panel. All 16 case formats update instantly in the transformation grid below the editor. Click any card to display that format in the main output panel for easy reading of longer texts. Click the copy icon on any card to copy that format directly.
Use the Viewing dropdown to select which case format appears in the main output panel. The Swap button replaces the input with the current output — useful for chaining conversions.
Star any format to add it to your Favorites group, which appears at the top of the grid for quick access. Favorites persist across sessions.
Text case formats
UPPERCASE converts every character to its capital form. Used for constants, headings, acronyms, and emphasis.
lowercase converts every character to its lowercase form. Used for normalization, email addresses, and URLs.
Title Case capitalizes major words while keeping articles (a, an, the), short prepositions (in, of, on, at), and conjunctions (and, but, or) in lowercase — unless they appear as the first or last word. This follows AP and Chicago style title capitalization rules.
Sentence case capitalizes the first letter of each sentence and after each newline. Useful for writing headings that should read like sentences.
Toggle Case and Inverse Case flip the case of every character — uppercase becomes lowercase, and vice versa. Alternating Case alternates lower and UPPER for each letter, producing the spongebob-style mocking text effect.
Programming naming conventions
camelCase — the first word is lowercase, subsequent words start with an uppercase letter. Used for JavaScript variables, function names, JSON keys, and Java fields: getUserName, totalItemCount.
PascalCase — every word starts with an uppercase letter, no separators. Used for class names, React components, TypeScript interfaces, and C# types: UserProfile, ShoppingCart.
snake_case — all lowercase words joined by underscores. The standard for Python variables, Ruby methods, SQL columns, and C identifiers: user_id, first_name.
SCREAMING_SNAKE_CASE — all uppercase with underscores. The standard for constants in most languages: MAX_RETRY_COUNT, DATABASE_URL.
kebab-case — all lowercase with hyphens. Used for URLs, HTML attributes, CSS class names, and npm package names: font-size, react-query, my-awesome-project.
Train-Case is the capitalized variant of kebab — used in HTTP header names: Content-Type, X-Request-Id.
Features
- 16 case formats — all converted simultaneously, no mode switching needed
- Transformation grid — all formats visible at once with per-card copy buttons
- Favorite formats — star your most-used cases, they appear at the top of the grid
- Text stats — character count, words, sentences, paragraphs, and lines update live
- Smart word splitting — understands camelCase, PascalCase, snake_case, and kebab input
- Text cleanup — remove extra spaces, trim lines, collapse whitespace, remove blank lines
- Export all — download all 16 conversions as a JSON object or formatted TXT file
- Swap button — replace input with converted output for chained conversions
- Operation history — last 5 conversions saved in localStorage
- 100% private — all processing runs in your browser, nothing is transmitted
Frequently asked questions
What is the difference between Title Case and Sentence case?
Title Case capitalizes the first letter of major words while keeping short words like a, the, and, in lowercase. It follows standard headline capitalization rules. Sentence casecapitalizes only the first letter of the first word in each sentence — it reads more like a normal sentence than a headline.
What programming language uses camelCase?
camelCase is the standard naming convention for variables and functions in JavaScript, TypeScript, Java, Swift, Kotlin, and Dart. JSON keys are also commonly written in camelCase. React component props use camelCase, while component names use PascalCase.
When should I use snake_case vs kebab-case?
Use snake_case for programming identifiers — Python variables, Ruby methods, PostgreSQL column names, and C constants. Use kebab-casefor things that appear in URLs and HTML — CSS class names, HTML element IDs, URL slugs, npm package names, and Git branch names. Hyphens are not valid in most programming language identifiers, so kebab-case is avoided there.
How does the smart word splitter work?
The tool automatically detects word boundaries regardless of your input format. It recognizes camelCase boundaries (helloWorld → hello, world), PascalCase boundaries (HelloWorld → hello, world), underscores (hello_world), hyphens (hello-world), dots, and regular spaces. This means you can paste any naming convention as input and get all other conventions as output.
What is SCREAMING_SNAKE_CASE used for?
SCREAMING_SNAKE_CASE (also called UPPER_SNAKE_CASE or MACRO_CASE) is the convention for constants in most programming languages. In Python it is used for module-level constants, in JavaScript/TypeScript for constvalues that should not be reassigned, in C/C++ for macro definitions, and in environment variables (DATABASE_URL, API_KEY).
Can I convert multi-line text?
Yes. For text case formats (UPPERCASE, Title Case, Sentence case, etc.), the tool processes the entire text as one block, respecting line breaks where relevant. For programming conventions (camelCase, snake_case, etc.), each non-empty line is converted independently, so you can paste a list of identifiers and convert them all at once.
What does the Export button do?
The JSON export downloads a .json file containing all 16 conversions as a JSON object, with the format ID as the key. The TXT export downloads a formatted plain-text file listing each format name and its converted value. Both are useful for sharing conversion results or using them in scripts.