Text Case Conversion — A Developer Reference for Naming Conventions

Every programming language, framework, and platform has its own naming convention. JavaScript uses camelCase for variables. Python uses snake_case. CSS uses kebab-case. React components use PascalCase. Database columns might use SCREAMING_SNAKE_CASE.

The challenge comes when you're working across boundaries — generating code from a schema, parsing an API response, or renaming a field across a codebase. That's where Text Case Converter saves time.

The Complete Naming Convention Reference

camelCase

First word lowercase, subsequent words capitalized. No separators.

userName  createdAt  getUserById  isAuthenticated

Used in: JavaScript/TypeScript variables and functions, JSON keys, Java variables, Swift variables.

PascalCase (UpperCamelCase)

Every word capitalized. No separators.

UserName  CreatedAt  GetUserById  IsAuthenticated

Used in: JavaScript/TypeScript class and component names, C# types, Java classes, Go exported names.

snake_case

All lowercase, words separated by underscores.

user_name  created_at  get_user_by_id  is_authenticated

Used in: Python variables and functions, Ruby, SQL column names, Unix file names, Rust variables.

SCREAMING_SNAKE_CASE (UPPER_SNAKE_CASE)

All uppercase, words separated by underscores.

USER_NAME  CREATED_AT  MAX_RETRY_COUNT  API_BASE_URL

Used in: Constants in most languages, environment variables, C/C++ macros, Python constants.

kebab-case (hyphen-case)

All lowercase, words separated by hyphens.

user-name  created-at  get-user-by-id  is-authenticated

Used in: CSS class names and custom properties, HTML attributes, URL slugs, npm package names, YAML/JSON config keys in some systems.

dot.case

All lowercase, words separated by dots.

user.name  created.at  app.config.debug

Used in: Java/Kotlin package names, property files, some configuration systems.

Title Case

Each word capitalized, separated by spaces.

User Name  Created At  Get User By Id

Used in: Headings, button labels, navigation items, human-readable field names.

Sentence case

First word capitalized, the rest lowercase, separated by spaces.

User name  Created at  Get user by id

Used in: UI labels, error messages, accessibility text.

Quick Reference Table

Converting Between Cases: The Algorithm

Converting any case to another requires two steps:

1. Tokenize — split the input into individual words, regardless of the source format
2. Reassemble — join words in the target format

The tricky part is tokenization. A robust tokenizer must handle:

• Word boundaries from separators (_, -, ., space)
• CamelCase boundaries (userName → ["user", "Name"])
• Consecutive uppercase sequences (HTMLParser → ["HTML", "Parser"] or ["HTML", "Parser"])

function tokenize(input) {
  return (
    input
      // Insert space before uppercase letters following lowercase (camel/pascal)
      .replace(/([a-z])([A-Z])/g, '$1 $2')
      // Insert space before sequences of uppercase followed by lowercase (HTMLParser → HTML Parser)
      .replace(/([A-Z]+)([A-Z][a-z])/g, '$1 $2')
      // Replace separators with space
      .replace(/[-_.]+/g, ' ')
      .trim()
      .split(/\s+/)
      .map((w) => w.toLowerCase())
  )
}

Practical Use Cases

Converting API responses to local variables

REST APIs typically return snake_case JSON keys. If your codebase uses camelCase, you'll want to transform keys on ingestion:

// Convert all keys in an object from snake_case to camelCase
function keysToCamel(obj) {
  return Object.fromEntries(Object.entries(obj).map(([k, v]) => [toCamelCase(k), v]))
}

Generating code from a schema

If you're building a code generator from a database schema or OpenAPI spec, you'll need to map column names (usually snake_case) to the appropriate convention for the target language.

Renaming across a codebase

When a rename affects both JS code (camelCase) and CSS (kebab-case) and database columns (snake_case), having a fast converter to hand-check the transformations prevents typos.

Using the Text Case Converter

The Text Case Converter accepts input in any format and converts to all cases simultaneously — useful when you need the same identifier in multiple formats at once.

→ Open Text Case Converter