Case Converter — Transform Text Between Every Case Format Developers and Writers Need

Text case mismatches create friction at every handoff between systems, teams, and tools. A database schema that uses snake_case column names — first_name, last_name, created_at — must be converted to camelCase when those field names appear in a JavaScript API response: firstName, lastName, createdAt. A marketing headline written in sentence case needs to become title case for a press release and ALL CAPS for a banner ad without manual retyping of each word. A block of pasted text from a source that used random mixed casing needs to be normalized before it can be copy-edited. Converting case manually — letter by letter, word by word — for anything beyond a handful of words wastes time that should not be spent on mechanical text transformation.

Developer case formats go beyond the simple uppercase-lowercase distinction that word processors handle. camelCase capitalizes every word after the first with no separators — the dominant convention in JavaScript, Java, and Swift variable names. PascalCase capitalizes every word including the first — the convention for class names in most object-oriented languages. snake_case uses underscores as separators with all lowercase — the convention in Python, Ruby, and SQL. kebab-case uses hyphens — the convention in CSS class names, HTML attributes, and URL slugs. SCREAMING_SNAKE_CASE uses underscores with all uppercase — the convention for environment variables and constants. Each convention exists in a specific ecosystem and switching between them when moving code, documentation, or data between systems is a real, recurring task.

Title case rules are more complex than capitalizing every word — standard title case style guides specify which words should remain lowercase. Articles (a, an, the), coordinating conjunctions (and, but, or, nor, for, yet, so), and short prepositions (in, on, at, by, to, of, up) are typically lowercased unless they appear as the first or last word of the title. Different style guides — Chicago Manual of Style, AP Stylebook, APA — have slightly different rules about which prepositions to capitalize based on word length. The case converter implements Chicago-style title case by default with style options, producing correctly formatted headlines rather than naively capitalizing every word regardless of its grammatical function.