Case Converter
Convert your text to any case format instantly. UPPERCASE, lowercase, Title Case, camelCase, snake_case, and more.
📖 How to Use
Type or paste your text in the input box, then click any conversion button to transform it. The converted text appears instantly — click the copy button to use it anywhere.
Case Types Explained
UPPERCASE
Converts all letters to capitals. Used for headlines, emphasis, or constants in programming. Example: "HELLO WORLD"
lowercase
Converts all letters to small case. Useful for normalizing text or creating email addresses. Example: "hello world"
Title Case
Capitalizes the first letter of each word. Standard for book titles, headings, and article titles. Example: "Hello World"
Sentence case
Capitalizes only the first letter of each sentence. The most natural reading format. Example: "Hello world. This is great."
camelCase
No spaces, each word after the first is capitalized. Standard in JavaScript and Java for variable names. Example: "helloWorld"
snake_case & kebab-case
Words joined with underscores or hyphens. Common in Python (snake_case) and CSS/URLs (kebab-case). Example: "hello_world" or "hello-world"
When to Use Case Conversion
Case conversion comes up more often than you'd think. Writers use it to fix accidentally typed caps lock text. Developers use it to convert between naming conventions when switching programming languages. SEO professionals use title case for meta titles and sentence case for descriptions.
If you're working with CSV files or databases, normalizing text case before importing prevents duplicate entries caused by inconsistent capitalization. Converting "New York", "new york", and "NEW YORK" to a single format saves hours of cleanup.
Naming Conventions for Developers
Every programming language and framework has its own naming convention. Using the wrong case doesn't just look inconsistent — it can break linters, confuse teammates, and violate style guides that block your pull requests. Here's a quick reference for the most common conventions.
camelCase — JavaScript & TypeScript
Variables, functions, and methods: getUserName, isLoading, handleClick. This is the standard enforced by ESLint and most JS style guides including Airbnb and Google.
snake_case — Python & Ruby
Variables, functions, and file names: get_user_name, is_loading, handle_click. PEP 8 (Python) and the Ruby style guide both mandate snake_case for methods and variables.
PascalCase — Classes & Components
Class names and React components: UserProfile, HttpClient, NavBar. PascalCase is universal across nearly all languages for class and type names, and required for React/Vue components.
kebab-case — CSS & URLs
CSS class names and URL slugs: .nav-bar, /user-profile, my-component. Kebab-case is the standard for BEM methodology, Tailwind custom classes, and SEO-friendly URLs.
SCREAMING_SNAKE_CASE — Constants
Constants and environment variables: MAX_RETRIES, API_BASE_URL, DATABASE_HOST. Used across JavaScript, Python, Java, Go, and most other languages to signal immutable values.
Switching Between Languages
Working on a full-stack project? You might write getUserData in your JS frontend and get_user_data in your Python API. Use this tool to convert between them instantly instead of retyping.
Frequently Asked Questions
What's the difference between Title Case and Sentence case?
Title Case capitalizes the first letter of every word ("The Quick Brown Fox"). Sentence case only capitalizes the first letter of each sentence ("The quick brown fox"). Title Case is used for headings; Sentence case is for regular text.
When should I use camelCase vs snake_case?
camelCase is the convention in JavaScript, Java, and TypeScript. snake_case is standard in Python, Ruby, and database column names. kebab-case is used in CSS class names and URLs. Use whatever your language or framework expects.
Is my text stored anywhere?
No. All conversion happens in your browser. Nothing is sent to a server — your text stays completely private.
Does the converter handle multi-word input for camelCase and snake_case?
Yes. Paste a phrase like "user profile settings" and the tool will convert it to userProfileSettings (camelCase) or user_profile_settings (snake_case). It splits on spaces, hyphens, and underscores to determine word boundaries.
Can I convert multiple lines at once?
Yes. Paste multiple lines and the converter processes each line independently. This is useful for batch-converting a list of variable names or CSS class names.