How to Convert Text Case: The Complete Guide
Whether you are writing an essay, coding a program, or formatting a social media post, you will eventually need to convert text between different cases. This guide covers every common text case style, when to use each one, and the fastest ways to convert between them.
What Are Text Cases?
A text case (or letter case) is a style that determines which letters in a word are uppercase and which are lowercase. Different contexts require different cases. Here are the most common ones:
UPPERCASE
Every letter is capitalized. Used for acronyms (NASA, HTML), headings, emphasis, and legal documents. To convert to uppercase, use our UPPERCASE converter.
Example:
hello world → HELLO WORLD
lowercase
Every letter is lowercase. Used for email addresses, domain names, CSS properties, and casual writing. Convert with our lowercase converter.
Example:
HELLO WORLD → hello world
Title Case
The first letter of each word is capitalized. Used for titles, headings, and book names. For proper title case following AP or Chicago style rules, use our Smart Title Case tool.
Example:
hello world → Hello World
Sentence case
Only the first letter of each sentence is capitalized. The standard for paragraphs, emails, and most writing. Use our Sentence Case converter.
Example:
HELLO WORLD. THIS IS A TEST. → Hello world. This is a test.
camelCase
Words are joined without spaces, and each word after the first starts with a capital letter. The standard naming convention in JavaScript, Java, and TypeScript for variables and functions. Convert with our camelCase converter.
Example:
hello world → helloWorld
snake_case
Words are separated by underscores and all lowercase. Used in Python, Ruby, database column names, and file names. Use our snake_case converter.
Example:
Hello World → hello_world
kebab-case
Words are separated by hyphens and all lowercase. Used in CSS class names, URL slugs, and HTML attributes. Convert with our kebab-case converter.
Example:
Hello World → hello-world
PascalCase
Like camelCase, but the first letter is also capitalized. Used for class names in JavaScript, C#, Java, and React component names. Use our PascalCase converter.
Example:
hello world → HelloWorld
How to Convert Text Case Online
The fastest way to convert text case is using a free online tool:
- Go to Convert Case Tool
- Paste your text in the input box
- Click the case you want (UPPER, lower, Title, camelCase, etc.)
- Copy the result
All conversion happens instantly in your browser. No text is ever sent to a server.
When to Use Each Case
| Case | Use For | Example |
|---|---|---|
| UPPERCASE | Acronyms, headings, emphasis | NASA, HTML, README |
| lowercase | Email, domains, CSS | user@email.com |
| Title Case | Titles, headings, names | The Great Gatsby |
| Sentence case | Paragraphs, emails, comments | This is a sentence. |
| camelCase | JS/TS variables, functions | getUserName |
| snake_case | Python, databases, files | user_name |
| kebab-case | CSS, URLs, HTML | my-component |
| PascalCase | Classes, React components | UserProfile |
| CONSTANT_CASE | Environment variables, constants | API_KEY |
Tips for Developers
- JavaScript: Use camelCase for variables/functions, PascalCase for classes/components, CONSTANT_CASE for constants
- Python: Use snake_case for variables/functions, PascalCase for classes, CONSTANT_CASE for constants
- CSS: Use kebab-case for class names and custom properties
- Databases: Use snake_case for table and column names
- URLs: Use kebab-case for readable, SEO-friendly slugs
Accidentally Typed in Wrong Case?
If you typed with Caps Lock on by accident, use our Fix Caps Lock tool to swap the case instantly. It inverts every letter, turning hELLO wORLD back to Hello World.