Case Converter
Convert text between UPPER, lower, Title, camelCase, snake_case, and more online for free. Nine conversion modes for any use case.
How to Use
Converting text between different letter cases is a common task for writers, developers, and content creators. This free online case converter transforms your text between nine different casing formats instantly. Here is how to use it:
- Paste or type your text into the input area. The tool accepts any length of text, from a single word to entire documents.
- Select a conversion mode by clicking one of the case buttons: UPPER CASE, lower case, Title Case, Sentence case, camelCase, PascalCase, snake_case, kebab-case, or CONSTANT_CASE.
- View the converted result in the output area. The conversion happens instantly with no processing delay.
- Copy the result using the copy button. The converted text is copied to your clipboard, ready to paste into your editor, terminal, or document.
You can apply multiple conversions in sequence. For example, paste a CONSTANT_CASE variable name, convert it to camelCase, then convert that to kebab-case. Each conversion starts fresh from the original input, so you can experiment freely.
Quick Reference: Case Formats
- UPPER CASE — ALL LETTERS CAPITALIZED. Used for acronyms, headings, and emphasis.
- lower case — all letters lowercase. The default for most running text.
- Title Case — First Letter Of Each Major Word Capitalized. Used for headlines and titles.
- camelCase — firstWordLowerThenCapitalized. Standard for JavaScript and TypeScript variables.
- snake_case — words_separated_by_underscores. Standard for Python, Ruby, and database columns.
- kebab-case — words-separated-by-hyphens. Standard for CSS classes and URL slugs.
About This Tool
Text case conversion is the process of changing the capitalization pattern of text to match a specific convention. While uppercase and lowercase are the most basic transformations, modern computing has introduced numerous case formats, each with its own rules and use cases. Understanding these conventions is essential for writing clean code, formatting professional documents, and creating consistent content.
In software development, naming conventions serve as a form of self-documentation. A variable named userName (camelCase) is immediately identifiable as a JavaScript variable, while user_name (snake_case) signals Python or Ruby. UserName (PascalCase) indicates a class or type name in most languages. MAX_RETRY_COUNT (CONSTANT_CASE) denotes an immutable constant. These conventions are not arbitrary — they carry semantic meaning that helps developers understand code at a glance.
Title Case has its own complexity. Different style guides prescribe different rules: the AP Stylebook lowercases prepositions of three or fewer letters, the Chicago Manual of Style lowercases prepositions of any length, and APA Style capitalizes words of four or more letters. This tool follows the AP convention, which is the most widely used in digital content.
Programming Naming Conventions by Language
Each programming language has established conventions for identifier naming. JavaScript and TypeScript use camelCase for variables and functions, PascalCase for classes and components, and CONSTANT_CASE for constants. Python follows PEP 8: snake_case for variables and functions, PascalCase for classes, and CONSTANT_CASE for module-level constants. CSS uses kebab-case exclusively for class names, custom properties, and data attributes. Go uses PascalCase for exported identifiers and camelCase for unexported ones, with no underscores at all. Understanding and converting between these formats is a daily task when working across multiple languages or porting code between ecosystems.
Beyond programming, case conversion is critical for content creation. Headline formatting requires Title Case in most editorial contexts. Email subject lines perform better with Sentence case according to A/B testing data. Database column names typically follow snake_case for SQL compatibility. URL slugs use kebab-case for readability and SEO benefit. A case converter that supports all these formats eliminates manual reformatting and reduces the risk of inconsistency.
Why Use This Tool
Case conversion is a daily necessity in programming, writing, and content management. Here are the most common scenarios where a case converter saves time:
- Refactoring code identifiers — When migrating code between languages (e.g., Python to JavaScript), variable names need to change from snake_case to camelCase. Doing this manually across hundreds of identifiers is error-prone. A case converter ensures consistent transformation.
- Creating URL slugs — Content management systems require URL-friendly slugs in kebab-case. Converting article titles like "How to Build a REST API" to "how-to-build-a-rest-api" is a single click with a case converter.
- Formatting headlines and titles — Writers and editors need Title Case for article headlines, book titles, and presentation slides. Manual capitalization is tedious and inconsistent, especially with rules about lowercasing articles and prepositions.
- Database and API work — Converting between camelCase (JSON APIs), snake_case (SQL databases), and PascalCase (C# models) is routine in full-stack development. A converter handles edge cases like acronyms and numbers correctly.
- Generating constants and environment variables — Configuration keys and environment variables follow CONSTANT_CASE by convention (e.g., DATABASE_URL, API_SECRET_KEY). Converting descriptive names to this format ensures consistency across deployment configurations.
Privacy and Simplicity
This case converter processes all text locally in your browser. No data is sent to any server, making it safe for converting proprietary code, internal documentation, and sensitive content. There is no signup, no usage limit, and no ads within the tool.