🔠 Case Converter

How to Use the Case Converter

Paste or type your text in the box above, then click any case conversion button to instantly transform your text. Click the "Copy" button to copy the result to your clipboard. The converter accepts text in any existing case format and intelligently normalizes it before applying the target case.

All Supported Case Styles

UPPERCASE converts every letter to its capital form. Use for headings, legal text, design elements emphasizing importance, acronyms, and abbreviations. In formal writing, avoid using ALL CAPS for running text as it is perceived as shouting. Example: hello world → HELLO WORLD.

lowercase converts every letter to its small form. Use for normalizing text data for string comparison, generating email addresses, creating URL-safe strings, and CSS property values. Example: HELLO World → hello world.

Title Case capitalizes the first letter of major words while leaving articles, short prepositions, and conjunctions lowercase (unless they are the first word). Follows standard English title capitalization conventions. Use for book titles, article headlines, product names, and page headings. Example: the quick brown fox → The Quick Brown Fox.

Sentence case capitalizes only the first letter of the first word in each sentence. This is the standard case for body text, email subjects, UI labels, and form field labels. Example: hello world. goodbye moon. → Hello world. Goodbye moon.

camelCase (lowerCamelCase) removes word separators and capitalizes each word after the first, which starts lowercase. This is the dominant convention for variable names and function names in JavaScript, TypeScript, Java, Swift, and Kotlin. Example: user first name → userFirstName.

PascalCase (UpperCamelCase) removes word separators and capitalizes every word including the first. Standard for class names, constructor functions, React component names, and type names in TypeScript and C#. Example: user account → UserAccount.

snake_case replaces spaces with underscores and lowercases everything. The dominant convention for Python variables, function names, and module names; also standard for database column names in PostgreSQL and MySQL by convention. Example: User Name → user_name.

kebab-case replaces spaces with hyphens and lowercases everything. Standard for CSS class names, HTML custom element names, URL slugs, file names in web projects (e.g., my-component.js), and Lisp-derived conventions. Example: Main Header → main-header.

CONSTANT_CASE (SCREAMING_SNAKE_CASE) replaces spaces with underscores and uppercases everything. Used for named constants and environment variables in virtually every programming language. Example: api base url → API_BASE_URL.

dot.case replaces spaces with dots and lowercases everything. Used in Java package names, Gradle/Maven configuration keys, some configuration file formats (e.g., log.level.debug), and object property path notation. Example: user settings → user.settings.

Case Conventions by Context

• JavaScript/TypeScript: camelCase for variables and functions, PascalCase for classes and React components, CONSTANT_CASE for constants, kebab-case for CSS module class names and file names.
• Python: snake_case for variables, functions, and modules (PEP 8), PascalCase for classes, CONSTANT_CASE for module-level constants.
• Java/Kotlin: camelCase for variables and methods, PascalCase for classes and interfaces, CONSTANT_CASE for static final constants, dot.case for package names.
• CSS/HTML: kebab-case for class names, IDs, custom properties (--my-color), and HTML attribute values.
• Databases (SQL): snake_case is standard for table and column names in PostgreSQL, MySQL, and most SQL databases.
• Writing/Publishing: Title Case for headlines, book titles, and article headings. Sentence case for subheadings, captions, and UI labels.
• Go (Golang): PascalCase for exported identifiers, camelCase for unexported identifiers. No underscores by convention.
• Rust: snake_case for functions and variables, PascalCase for types and traits, CONSTANT_CASE for statics and constants.
• C#: PascalCase for public members and types, camelCase with leading underscore (_camelCase) for private fields, CONSTANT_CASE for constants.

When Case Conversion Matters Most

Case conversion is particularly important in software development contexts where mixing conventions causes bugs or technical issues:

• Database migrations: When renaming database columns, ensure your ORM model properties match the exact case the database expects. Mismatches between userId and user_id cause silent query failures in production.
• API integration: Many APIs use snake_case for JSON keys (Python convention), while JavaScript front-ends prefer camelCase. Converting between the two during data normalization is a common task when building full-stack applications.
• Code refactoring: When renaming a function or class to match your team's style guide, you need to update all references. Converting the old name to the correct new case format makes it easy to search for every occurrence.
• Content management: When migrating content between a CMS and a headless API, field names often need to be normalized from Title Case or Sentence case to camelCase or snake_case for programmatic access.
• Internationalization (i18n): Translation key naming conventions vary by framework. React i18next uses dot notation (header.title), while iOS uses camelCase (headerTitle). This tool makes bulk conversion of key names straightforward.
• SEO and slugs: Article titles in Title Case must be converted to kebab-case before use as URL slugs. The Text to Slug tool handles accented characters and special symbols automatically.

Case Conversion in Excel and Google Sheets

Spreadsheet applications have built-in case functions, but they are limited. Excel and Google Sheets offer UPPER(), LOWER(), and PROPER() (which is Title Case). However, they do not support camelCase, snake_case, kebab-case, or any programming-specific naming convention. This makes the FixMyString converter invaluable for data processing workflows where you need to convert column headers or data values into a format usable in code.

Related Tools

• Text to Slug — Convert text directly to URL-safe kebab-case slugs with accented character handling.
• Find & Replace — Edit specific parts of text before converting case.
• Word Counter — Count words and characters in your converted text.
• Whitespace Cleaner — Remove extra spaces before case conversion for clean results.