Sponsored placement
When Case Conversion Matters in Development
Different programming languages, frameworks, and contexts enforce different naming conventions. JavaScript and TypeScript use camelCase for variables and functions. Python uses snake_case for variables and functions, and PascalCase for classes. CSS uses kebab-case for class names and custom properties. Database column names typically use snake_case. SQL reserved words are conventionally written in UPPER CASE.
When you copy text from one context to another — a column name to a JavaScript variable, a CSS class to a React component prop, a database field to a Python function argument — you need to convert the case to match the target convention. Doing this by hand is slow and error-prone, especially for multi-word names with ten or more words.
API response fields often arrive in snake_case from a Python or Ruby backend, while the JavaScript frontend expects camelCase. URL paths use kebab-case while the corresponding route handler parameters use camelCase. A case converter makes these cross-language boundary conversions instant.
- JavaScript and TypeScript: camelCase for variables and functions, PascalCase for classes and React components
- Python: snake_case for variables and functions, PascalCase for classes, CONSTANT_CASE for constants
- CSS: kebab-case for class names, custom properties, and HTML attributes
- Databases: snake_case for column names, UPPER CASE for SQL keywords
- URLs: kebab-case for paths and slugs
- Environment variables: CONSTANT_CASE (uppercase with underscores)
The 10 Case Formats Explained
UPPER CASE converts all letters to uppercase with spaces preserved. lower case converts all letters to lowercase. Title Case capitalizes the first letter of each word and lowercases the rest. Sentence case capitalizes only the first letter of the entire text. These four formats are primarily for display text and prose.
camelCase joins words together and capitalizes the first letter of every word except the first: helloWorldExample. PascalCase (also called UpperCamelCase) does the same but also capitalizes the first word: HelloWorldExample. snake_case joins words with underscores and lowercases everything: hello_world_example. kebab-case joins words with hyphens and lowercases everything: hello-world-example.
CONSTANT_CASE is like snake_case but with all uppercase letters, used for constants and environment variables: HELLO_WORLD_EXAMPLE. dot.case joins words with periods and lowercases everything: hello.world.example. This format appears in configuration keys, package names, and some file naming conventions.
Common Use Cases for Case Conversion
When designing a database schema, column names are typically written in snake_case. When those columns are used in a JavaScript ORM like Prisma, the field names in the TypeScript schema are camelCase. When the data is served through a REST API, the JSON keys may need to be camelCase for frontend consumption. A case converter lets you translate the same concept name across all three representations instantly.
When writing blog posts or documentation, you often need the same term in multiple formats for different contexts: in prose as Title Case, as a code variable in camelCase, as a CSS class in kebab-case, and as a URL slug also in kebab-case. Paste the phrase once and copy each format as needed.
When renaming files, functions, or CSS classes across a codebase during a refactor, having all case variants visible at once makes it easy to apply the right convention in each context without remembering conversion rules for each language.
Why marketers use this tool
- Convert text to 10 different cases in real time — camelCase, PascalCase, snake_case, kebab-case, and more
- Copy any single case format with one click without selecting all outputs
- Useful for renaming variables, formatting titles, and switching between coding conventions
Frequently Asked Questions
What is camelCase and when should I use it?
camelCase writes compound words with no spaces, with each word after the first starting with a capital letter: myVariableName. The name comes from the humps created by the capital letters. Use camelCase for variable names, function names, and method names in JavaScript, TypeScript, Java, and most C-family languages. In JavaScript specifically, camelCase is the convention for everything except class names, which use PascalCase, and constants, which use UPPER_CASE.
What is the difference between PascalCase and camelCase?
PascalCase (also called UpperCamelCase) capitalizes the first letter of every word including the first one: MyClassName. camelCase (also called lowerCamelCase) capitalizes every word except the first: myVariableName. PascalCase is used for class names, type names, interface names, enum names, and React component names. camelCase is used for variable names, function names, and instance properties.
Why is snake_case used in Python and SQL?
PEP 8, the official Python style guide, specifies snake_case for variable names, function names, and module names because it is more readable in Python code, which tends to have longer descriptive names than C-style languages. SQL column names use snake_case because SQL is case-insensitive and spaces in identifiers require quoting, making snake_case the practical standard. Database ORMs in Python (like SQLAlchemy and Django ORM) follow the same convention.
What is kebab-case used for?
kebab-case (words joined by hyphens) is the convention for CSS class names, CSS custom property names, HTML attributes, URL slugs, and URL path segments. It is called kebab-case because the hyphens resemble skewers. HTML and CSS are case-insensitive in most contexts, and hyphens are more readable than underscores in URLs. Most front-end frameworks and design systems use kebab-case for component names in HTML templates and for CSS utility classes.
How does this tool handle numbers and special characters?
Numbers are treated as part of the word they appear in. Special characters like hyphens, underscores, periods, slashes, and spaces are treated as word separators and removed in cases that use a different separator (camelCase, PascalCase, UPPER CASE, lower case, Sentence case, Title Case). Non-ASCII characters like accented letters are kept as-is in most case formats but may be lowercased or uppercased depending on the target format.