Case Converter
Switch between nine naming styles while preserving readable word boundaries.
Runs in your browser. Nothing is uploaded.
Convert common naming styles
Case Converter changes the capitalization and separators in ordinary text. Use it for labels, headings, API examples, file names, variable ideas, or small pieces of documentation. Choose Upper or Lower to change only the letter case of the original text. The word-based modes split text into words, then apply a consistent style to the result.
Title Case capitalizes each word and joins words with spaces. Sentence case lowercases the text and capitalizes the first letter after a sentence boundary. camelCase starts with a lowercase word and capitalizes later words. PascalCase capitalizes every word without separators. snake_case, kebab-case, and CONSTANT_CASE use underscores, hyphens, or uppercase letters to make boundaries visible.
How words are detected
The converter recognizes spaces, underscores, and hyphens as word separators. It also recognizes common camelCase and PascalCase boundaries, including the boundary between an acronym and a normal word. Letters and numbers are kept as useful parts of the result, with a boundary between them when that makes the words easier to read. Punctuation is treated as a separator for word-based modes, while Upper and Lower preserve the original punctuation and spacing.
Unicode letters are supported through the browser's normal case conversion, so words such as naïve remain readable. Case conversion can still be language-sensitive in ways that differ between locales. Review names with special capitalization rules before using them in a public interface or a generated identifier.
Conversion is not identifier validation
This tool produces a useful text representation. It does not check whether the result is a valid JavaScript, Python, CSS, SQL, or framework-specific identifier. A language can reserve words, limit the first character, or apply rules for Unicode identifiers that are different from this converter's word splitting. Validate the final name in the language or build system where it will be used.
Numbers, punctuation, acronyms, and leading separators can also carry meaning in your project. Use the Sample action to see the selected mode, then check the output against the naming convention in your repository. For a character-level comparison between the original and converted text, try Text Diff.
Private browser conversion
Input and output stay in your browser. Nothing is uploaded while you paste text, convert a mode, copy the result, or download converted.txt. Avoid putting credentials or private data in shared screenshots and browser history even when a tool works locally. When text needs URL representation rather than naming-style conversion, use URL Encode/Decode.
FAQ
Can I convert a private identifier without sending it away?
The converter calls its case engine in your browser, and the text is never uploaded. For word-based styles, it splits word boundaries locally before producing the selected case style.
Which case styles does the tool support?
The choices are upper, lower, title, sentence, camelCase, PascalCase, snake_case, kebab-case, and CONSTANT_CASE. The selected style changes separators and capitalization but does not validate an identifier.
How does it find word boundaries?
It separates a lowercase letter or digit before an uppercase letter, an acronym run before a capitalized word, and letters next to digits. It then splits on characters that are neither Unicode letters nor Unicode numbers.
How are numbers handled?
Letters and numbers remain in the result, with boundaries inserted when a letter meets a number or vice versa. For example, json2Csv becomes json_2_csv in snake_case.
What is the difference between title and sentence case?
Title case splits the input into words, lowercases each word, and capitalizes every word. Sentence case lowercases the complete input and capitalizes the first letter after the start or a period, question mark, or exclamation mark.
Does it support Unicode text?
Yes. Word detection uses Unicode-aware regular expressions and JavaScript's Unicode case conversion, so Unicode letters can stay in word-based output.
Can I download the converted text?
Yes. After conversion, Copy places the result on the clipboard and Download creates converted.txt in your browser. The download contains the converted text only.