Case Converter Online: The Complete Guide
Learn the difference between camelCase, snake_case, PascalCase, and kebab-case, when each is used, and how to convert between them online instantly.
Last updated: May 4, 2026
Why naming conventions matter
Every programming language, framework, and platform has its own naming convention for variables, functions, classes, files, and URLs. Mixing conventions in a single codebase reduces readability, causes linting errors, and signals inconsistency to code reviewers. A case converter online lets you quickly normalize identifiers to the right format for your target language or system.
Naming convention reference
getUserByIdFirst word lowercase, subsequent words capitalized, no separators.
Used in: JavaScript/TypeScript variables and functions, Java methods, Go unexported names, Swift methods, Dart variables.
UserRepositoryEvery word capitalized, no separators. Also called UpperCamelCase.
Used in: Classes in all OOP languages (Java, C#, Python, TypeScript), React components, Go exported names, C# everything.
user_repositoryAll lowercase, words separated by underscores.
Used in: Python variables, functions, and module names; Ruby; PostgreSQL column names; Rust variable names; C global variables.
MAX_RETRY_COUNTAll uppercase, words separated by underscores.
Used in: Constants in C, C++, Java, Python, and most languages. Environment variables (NODE_ENV, DATABASE_URL).
user-profile-pageAll lowercase, words separated by hyphens.
Used in: CSS class names and custom properties, HTML attribute names, URL slugs, npm package names, YAML keys.
user.profile.nameAll lowercase, words separated by dots.
Used in: Configuration keys (Spring Boot, .properties files), i18n translation keys, some logging contexts.
When do you need to convert between cases?
Mapping API responses to local variables
REST APIs commonly use snake_case JSON keys (following Python/Ruby conventions), while JavaScript frontends use camelCase. When building the TypeScript model for an API response, you need to know the camelCase equivalent of created_at (createdAt) and user_profile_url (userProfileUrl).
Renaming identifiers across language boundaries
When writing a Go backend that consumes data from a Python service, Go uses PascalCase for exported names and Python uses snake_case. Converting user_created_at to UserCreatedAt and back is a constant task in polyglot systems.
CSS class naming from design tokens
Design tokens from tools like Figma or Tokens Studio often come in PascalCase or camelCase. When translating them to CSS custom properties, they need to be kebab-case: ColorPrimaryBrand → --color-primary-brand.
Generating URL slugs from titles
Blog post titles, product names, and page titles need to be converted to URL-safe slugs. A case converter handles the transformation from "My First Blog Post" to my-first-blog-post (kebab-case, lowercase).
Database schema to application model mapping
PostgreSQL columns use snake_case (user_id, created_at). ORMs like Sequelize, TypeORM, and Prisma map these to camelCase properties in JavaScript. When writing raw SQL alongside an ORM, you switch between the two constantly.
How to convert cases online
Open the Case Converter on Vultio, paste your text (variable name, sentence, or list of identifiers), and all output formats are generated simultaneously: camelCase, PascalCase, snake_case, kebab-case, SCREAMING_SNAKE_CASE. Copy the format you need in one click. No server round-trip — runs instantly in your browser.
Language-by-language convention summary
| Language | Variables | Classes | Constants |
|---|---|---|---|
| JavaScript / TypeScript | camelCase | PascalCase | SCREAMING_SNAKE or camelCase |
| Python | snake_case | PascalCase | SCREAMING_SNAKE_CASE |
| Go | camelCase (unexported) | PascalCase (exported) | PascalCase |
| Java / Kotlin | camelCase | PascalCase | SCREAMING_SNAKE_CASE |
| Rust | snake_case | PascalCase | SCREAMING_SNAKE_CASE |
| C# | camelCase (private) | PascalCase | PascalCase |
| Ruby | snake_case | PascalCase | SCREAMING_SNAKE_CASE |
| PHP | camelCase (common) | PascalCase | SCREAMING_SNAKE_CASE |
Frequently asked questions
What is the difference between camelCase and PascalCase?
camelCase starts with a lowercase letter (getUserById). PascalCase (also called UpperCamelCase) starts with an uppercase letter (GetUserById). Both capitalize the first letter of every subsequent word.
Is kebab-case valid for JavaScript variable names?
No. Hyphens are subtraction operators in JavaScript, so my-variable is parsed asmy minus variable. Kebab-case is limited to CSS, URLs, HTML attributes, and file names. Use camelCase for JavaScript variable and function names.
Does case matter in SQL?
SQL identifiers are case-insensitive by default in most databases (MySQL, PostgreSQL without quoting). However, PostgreSQL preserves case when identifiers are double-quoted. Convention is to use lowercase snake_case for column and table names and uppercase for SQL keywords.
What is Title Case?
Title Case capitalizes the first letter of each word with spaces: "My Blog Post Title". It is used for article headings, page titles, menu items, and UI labels — not for code identifiers.
Does this tool handle acronyms correctly?
Common acronyms like URL, API, ID are normalized by word boundaries. For Go-style conventions where acronyms are fully capitalized (e.g. parseURL vs parseUrl), manual adjustment after conversion is recommended.