Unicode Multi-Format Case Converter & Case Folding Studio
Instantly convert any text across 16+ casing formats: UPPERCASE, lowercase, Title Case, camelCase, PascalCase, snake_case, kebab-case, Turkish locale, and official Unicode Full Casefolding (UTR #21).
Transforms all letters to capital characters.
Transforms all letters to small characters.
Capitalizes the first letter of each major word, keeping articles and prepositions lowercase.
Capitalizes the first letter of each grammatical sentence.
Standard for JavaScript, TypeScript, and Java variable naming.
Standard for React components, TypeScript types, and C# class names.
Standard for Python variables and SQL database column identifiers.
Standard for global constants and environment variables.
Standard for clean SEO URLs and CSS class names.
Used in properties files, configuration keys, and Java packages.
Used for file paths and directory routes.
Canonical case-insensitive equality mapping (German ß → ss, Greek final σ, ligatures).
Preserves the distinction between dotted i (İ) and dotless ı (I).
Correct Turkish/Azeri lowercase locale conversion.
Mocking Spongebob meme case with alternating capital and lowercase letters.
Reverses uppercase to lowercase and vice-versa.
The Architecture of Unicode Case Mapping & Casefolding (UTR #21)
In simple ASCII systems, converting between uppercase and lowercase is a trivial arithmetic shift of 32 code units (e.g. 'A' (65) + 32 = 'a' (97)). In the international Unicode Standard (Section 3.13), however, casing is a complex linguistic process involving multi-character expansions, context-dependent rules, and locale-specific constraints.
For instance, converting the German sharp S (ß) to uppercase expands one character into two ("SS" or capital "ẞ"). Similarly, the Greek capital letter Sigma (Σ) has two distinct lowercase forms: standard σ and word-final ς.
To solve case-insensitive comparison in databases, search engines, and URL routers, the Unicode Consortium created Case Folding (Unicode Technical Report #21). Case Folding normalizes characters to a canonical folded state so that searches for "WEISS", "weiß", and "WEISS" match identically without locale bugs.
Developer Casing Conventions Summary
Frequently Asked Questions (FAQs)
Why does JavaScript .toLowerCase() sometimes fail on foreign text?+
Standard .toLowerCase() in older ECMAScript runtimes applies default Unicode mappings without considering the user's active locale. For Turkish or Azerbaijani text, use string.toLocaleLowerCase("tr-TR") or our Turkish lowercase converter to avoid converting dotted "i" into dotless "ı".
What is the difference between Title Case and Capital Case?+
Capital Case capitalizes the first letter of every single word indiscriminately. Title Case (following AP and Chicago journalistic manuals) intelligently keeps articles (a, an, the) and prepositions (in, on, of, for) lowercase.
Is there a limit on text length or file size?+
No, this tool executes 100% locally in your browser memory using high-performance regex algorithms with zero word limits.