Convert text between all 9 case formats instantly: UPPERCASE, lowercase, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, Title Case, and Sentence case — with live preview and one-click copy.
A case converter (also called a text case changer or string case transformer) is a tool that reformats text between different capitalization styles. Each case style has a specific purpose in programming, writing, and design. Developers need to convert between cases constantly — a variable named in camelCase in JavaScript needs to become snake_case in Python, or CONSTANT_CASE in a configuration file. Writers need to switch between Title Case for headlines and Sentence case for body text. This tool converts your text into all nine standard case formats simultaneously, so you can copy whichever one you need.
| Case | Example | Primary Use |
|---|---|---|
| UPPERCASE | HELLO WORLD | Constants, acronyms, emphasis, shouting in informal writing, database column names in SQL |
| lowercase | hello world | HTML attributes, CSS class names (before kebab-case), email addresses, Unix filenames |
| camelCase | helloWorld | JavaScript, TypeScript, Java variables and function names; JSON property keys; React props |
| PascalCase | HelloWorld | Class names in most OOP languages (Python, Java, C#, TypeScript); React component names; C# methods |
| snake_case | hello_world | Python variables and functions; Ruby; database column names; Linux/Unix file and directory names |
| kebab-case | hello-world | HTML/CSS class names; URL slugs; npm package names; HTML data attributes; file names in web projects |
| CONSTANT_CASE | HELLO_WORLD | Constants in Python (PEP 8); environment variables (.env files); configuration keys; Redux action types |
| Title Case | Hello World | Article headlines; book titles; UI headings; product names; any formal heading in English writing |
| Sentence case | Hello world | Body text, descriptions, tooltips, UI labels, informal headings, email subjects |
Convert all characters to uppercase
Convert all characters to lowercase
First word lowercase, subsequent words capitalized, no spaces
All words capitalized, no spaces
Words separated by underscores, all lowercase
Words separated by hyphens, all lowercase
Words separated by underscores, all uppercase
First letter of each word capitalized
First letter capitalized, rest lowercase
camelCase starts with a lowercase letter (helloWorld), while PascalCase (also called UpperCamelCase) starts with an uppercase letter (HelloWorld). In JavaScript and TypeScript, camelCase is used for variables, functions, and object properties, while PascalCase is used for class names and React component names.
snake_case (underscores) is the standard in Python (PEP 8 style guide) for variable and function names, and is widely used for database column names. kebab-case (hyphens) is standard in CSS class names, HTML attributes, URL slugs, and npm package names. The key difference: hyphens are valid in URLs and CSS but not in most programming language identifiers; underscores are valid in identifiers but not in URLs.
CONSTANT_CASE (SCREAMING_SNAKE_CASE) is the standard for constants — values that never change — in Python (PEP 8), environment variables (.env files), Redux action type strings, and configuration keys. In JavaScript/TypeScript, it signals to other developers that a value should not be reassigned.
For programming cases (camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE), special characters and punctuation are removed since they are not valid in most programming language identifiers. For text cases (UPPERCASE, lowercase, Title Case, Sentence case), all characters including punctuation are preserved and only the capitalization changes.
Yes. Paste any amount of text — multi-line paragraphs, code snippets, or lists. The converter processes the entire input and shows results for all nine formats simultaneously. Use fullscreen mode for better visibility when working with large amounts of text.
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