capstring

CaPiTaLiZe StRiNgS in 29 ways!

A lightweight, zero-dependency library for text capitalization and transformation. Perfect for formatting strings for code, URLs, display, or fun!

Features

• 29 transformation styles - More than any other library!
• Zero dependencies - Lightweight and fast
• ESM native - Modern JavaScript modules
• 98% test coverage - Thoroughly tested

Installation

npm install capstring

Quick Start

import capstring from 'capstring';

capstring('hello world', 'title');     // 'Hello World'
capstring('hello world', 'camel');     // 'helloWorld'
capstring('hello world', 'kebab');     // 'hello-world'
capstring('hello world', 'constant');  // 'HELLO_WORLD'
capstring('hello world', 'leet');      // 'h3££0 w0r£d'
capstring('hello world', 'hashtag');   // '#HelloWorld'

All 29 Styles

Case Styles

Style	Input	Output
same	Hello World	Hello World
none	Hello World	(empty)
proper	Hello World	Hello World
title	hello world	Hello World
sentence	hello world	Hello world
upper	hello world	HELLO WORLD
lower	HELLO WORLD	hello world
swap	Hello World	hELLO wORLD

Code Styles

Style	Input	Output
camel	hello world	helloWorld
pascal	hello world	HelloWorld
snake	hello world	hello_world
kebab	hello world	hello-world
slug	hello world	hello-world
constant	hello world	HELLO_WORLD
python	hello world	HELLO_WORLD
dot	hello world	hello.world
path	hello world	hello/world
train	hello world	Hello-World

Fun Styles

Style	Input	Output
leet	hello world	h3££0 w0r£d
reverse	hello world	dlrow olleh
sponge	hello world	HeLlO WoRlD
mock	hello world	hElLo wOrLd
alternate	hello world	hElLo WoRlD
crazy	hello world	(deterministic random)
random	hello world	(random case)

New Styles

Style	Input	Output
hashtag	hello world	#HelloWorld
acronym	as soon as possible	ASAP
rot13	hello	uryyb
flip	hello	ollǝɥ

API

capstring(str, style)

Transform a string to the specified style.

import capstring from 'capstring';

capstring('hello world', 'title');  // 'Hello World'
capstring('hello world');           // 'hello world' (default: same)
capstring(123);                     // false (invalid input)

getStyles()

Get an array of all supported style names.

import { getStyles } from 'capstring';

getStyles();  // ['same', 'none', 'proper', 'title', ...]

isValidStyle(style)

Check if a style is supported.

import { isValidStyle } from 'capstring';

isValidStyle('kebab');    // true
isValidStyle('invalid');  // false

STYLES

Frozen array of all style names.

import { STYLES } from 'capstring';

STYLES.length;  // 29

REST API

Looking for an API? Check out cAPIta - a full REST API powered by capstring!

curl https://your-api.com/title/hello%20world
# {"input":"hello world","output":"Hello World","cap":"title"}

Development

npm install        # Install dependencies
npm test           # Run tests
npm run lint       # Run linter
npm run test:coverage  # Test with coverage

Contributing

Please read CONTRIBUTING.md for details on the code of conduct and the process for submitting pull requests.

Versioning

This project uses Semantic Versioning 2.0.

Requirements

• Node.js 18+
• ES modules (import/export)

License

MIT - Copyright 2016-2026 Brian Funk