Case Converter

Changing text case, explained

Letter case carries meaning. A headline in Title Case, a constant in CONSTANT_CASE, and a URL in kebab-case all follow conventions that readers and compilers expect. Retyping text just to flip its case is slow and error-prone. This converter applies nine well-defined casing rules to whatever you paste, so you can match a style guide, a coding standard, or a CMS field in one click.

The two prose cases: Title and Sentence

Title Case capitalizes the first letter of every word. It is what most blog and news headlines use. Sentence case capitalizes only the first word of each sentence and any proper nouns you have already capitalized — it is increasingly the house style for headlines at large publications because it reads more naturally. If you write UI labels or documentation headings, picking one of these and applying it consistently is an easy win for polish.

The programmer cases: camel, Pascal, snake, kebab, constant

Code identifiers cannot contain spaces, so different languages adopted different word-joining conventions:

• camelCase — JavaScript and Java variables and methods.
• PascalCase — class names, TypeScript types, React components.
• snake_case — Python variables, SQL columns, Rust functions.
• kebab-case — URL slugs, CSS class names, HTML attributes, npm packages.
• CONSTANT_CASE — environment variables and compile-time constants.

These transforms first split your text on any non-alphanumeric boundary, then rejoin the pieces using the rule above. That means "User Profile Page", "user-profile-page", and "user_profile_page" all convert cleanly between formats — handy when you are renaming something across a URL, a database, and your code at once.

A common gotcha: acronyms

Because case-insensitive rules have no way to know that "API" or "NASA" is an acronym, Title and Sentence case will render them as "Api" and "Nasa". There is no reliable automatic fix, so the practical approach is to convert first and then restore the handful of acronyms manually, or keep acronym-heavy text in UPPERCASE.

Recasing without a round trip

Flipping the case of a string is light work, and there is no reason to hand it to a server to do it. This converter applies every rule in the page itself, which keeps the transformation instant and means product copy, internal naming schemes, and other unreleased wording are never logged or stored by a third party.

Related text tools

• Slugify — turn a Title Case headline into a clean URL slug.
• Find and Replace — fix specific words after a case change.
• Word & Character Counter — check length once your text is recased.
• Remove Line Breaks — flatten multi-line text before converting it to an identifier.