Case Converter
Type or paste your text below and select a case transformation. Instantly convert between uppercase, lowercase, title case, sentence case, camelCase, snake_case, kebab-case, and CONSTANT_CASE.
How the Case Converter Works
This free online case converter transforms your text between eight different casing styles used in writing, programming, and data formatting. Each transformation applies specific rules to capitalize, lowercase, or restructure the characters in your text. The tool processes the entire input at once, handling multi-line text, special characters, and Unicode letters correctly. All conversion happens instantly in your browser with no server processing required.
Supported Case Transformations
UPPERCASE converts every letter to its capital form. lowercase converts every letter to its small form. Title Case capitalizes the first letter of each word. Sentence case capitalizes only the first letter of each sentence. camelCase joins words with the first word lowercase and subsequent words capitalized. snake_case joins words with underscores in all lowercase. kebab-case joins words with hyphens in all lowercase. CONSTANT_CASE joins words with underscores in all uppercase.
When to Use Different Case Styles
Different case styles serve different purposes across writing, programming, and design. UPPERCASE is commonly used for headings, acronyms, emphasis, and legal disclaimers. Lowercase is the default for body text and informal communication. Title Case is standard for headlines, book titles, and formal headings in English, where the first letter of each major word is capitalized. Sentence case is used for regular prose where only the first word and proper nouns are capitalized.
Programming naming conventions rely heavily on specific case styles. JavaScript and Java use camelCase for variable and function names. Python uses snake_case for variables and function names. CSS class names and URL slugs use kebab-case. Environment variables and constants in many languages use CONSTANT_CASE. Using the wrong naming convention in code can violate linting rules, break style guides, and reduce readability for other developers on your team.
camelCase and PascalCase in Programming
camelCase starts with a lowercase letter and capitalizes the first letter of each subsequent word, with no separators: getUserName, calculateTotalPrice, isVisible. It is the dominant convention in JavaScript, TypeScript, Java, and C# for local variables, function names, and method names. PascalCase is similar but starts with an uppercase letter and is typically used for class names and component names in React, Angular, and other frameworks.
snake_case and CONSTANT_CASE
snake_case separates words with underscores and uses all lowercase letters: user_name, calculate_total, is_visible. It is the standard naming convention in Python, Ruby, Rust, and database column names. CONSTANT_CASE, also known as SCREAMING_SNAKE_CASE, uses underscores with all uppercase letters: MAX_RETRIES, API_BASE_URL, DEFAULT_TIMEOUT. It is universally used for constants and environment variables across virtually all programming languages.
kebab-case for Web Development
kebab-case separates words with hyphens and uses all lowercase letters: user-profile, main-content, btn-primary. It is the standard for CSS class names, HTML attributes, URL slugs, and npm package names. Many web frameworks and component libraries enforce kebab-case for custom element names and directive names. This style is also used in file naming conventions for web projects.
Privacy and Security
All case conversion happens locally in your browser using JavaScript. Your text is never transmitted to any server. This makes the tool completely safe for converting proprietary code, confidential documents, and sensitive data. No text is stored beyond your current browser session.