Which case should I use for variables?

Depends on the language. JavaScript and TypeScript use camelCase. Python uses snake_case. C# and Go use PascalCase for types. URLs and files typically use kebab-case.

Does it handle special characters?

Yes. UPPER and lower preserve accents. Technical cases (camel, snake, kebab) strip accents per the usual identifier convention.

What is Sentence case?

Only the first letter of the sentence is capitalized, like normal prose. Great for fixing titles that arrived in ALL CAPS or all lowercase.

Case Converter (camelCase, snake_case, kebab-case)

Why so many casing styles exist

In programming, identifiers can't have spaces or punctuation. Each community picked a convention to combine words: some use capitals as separators (camelCase, PascalCase), others use underscores (snake_case) or hyphens (kebab-case). None is "best" in the abstract — what matters is consistency with the ecosystem you work in.

When to use each

camelCase — variables and functions in JavaScript, TypeScript, Java, C++.
PascalCase — classes, types, React components, models.
snake_case — variables and functions in Python, Ruby, Rust; database columns.
kebab-case — URLs, slugs, filenames, HTML attributes, CSS classes.
CONSTANT_CASE — global constants in nearly every language.
Title Case — article, book and product titles in English.
Sentence case — running prose; only the first word and proper nouns are capitalized.

Common mistakes

Mixing cases in the same project is the number one source of typo bugs. If your team uses userId in some places and user_id in others, somebody will eventually reference the wrong variable. Define the convention up front, ideally backed by a linter (ESLint, Pylint, gofmt) that enforces it.

Practical use cases

Take a SQL column name order_total_amount and convert it to the JS object property orderTotalAmount.
Turn an article title "10 Tips For Your Landing Page" into the slug 10-tips-for-your-landing-page.
Take text that arrived in ALL CAPS from a poorly exported PDF and downcase to Sentence case.
Generate a React component name (PascalCase) from a natural-language description.

Accents and special characters

UPPER, lower, Sentence and Title preserve accents and ñ. Technical modes (camel, snake, kebab, constant) strip them because most languages and filesystems don't accept accented identifiers. If you need accents in a slug, copy from Sentence/Title and replace spaces manually.

Local processing

This converter sends nothing to a server. The whole script runs in your browser, so you can paste confidential text without worrying about logs or analytics. Close the tab and it's gone.

Case Converter