Text Case Converter
Paste your text, pick a case, and copy the result. Useful for fixing a headline typed with caps lock on, or for renaming variables between the conventions different languages expect.
The programming cases, and when each one is used
Every language community settled on a different convention, and mixing them inside one codebase is the kind of thing that gets flagged in review. The short version:
- camelCase — variables and functions in JavaScript, Java, C# (methods use PascalCase), Swift and Kotlin.
- PascalCase — classes, types and components almost everywhere, plus C# methods and public members.
- snake_case — variables and functions in Python, Ruby and Rust, and the standard for SQL column names.
- CONSTANT_CASE — constants and environment variables across nearly every language.
- kebab-case — URLs, CSS class names, HTML attributes and npm package names. It cannot be used for identifiers in most languages because the hyphen reads as a minus sign.
For URLs specifically, hyphens rather than underscores are the long-standing recommendation from Google: hyphens are treated as word separators, underscores historically were not.
Title Case is not just capitalising everything
Proper title case leaves short function words lowercase unless they open or close the title — so "The Rise of the Machines", not "The Rise Of The Machines". This converter follows that rule for articles, conjunctions and prepositions of four letters or fewer.
Be aware that the major style guides disagree on the details. AP capitalises all words of four letters or more; Chicago lowercases all prepositions regardless of length; APA capitalises words of four letters or more. If you are writing to a specific style guide, check the result rather than trusting any tool — including this one.
Sentence case and the caps-lock rescue
The most common real use for a case converter is recovering a paragraph typed with caps lock on. Sentence case handles this: it lowercases everything, then capitalises the first letter of each sentence and the standalone pronoun "I".
What it cannot recover is proper nouns. Names, places, brands and acronyms all come back lowercase, because the original capitalisation that marked them was destroyed. Read the output before using it — this is a shortcut that gets you 90% of the way, not a fix.
A note on non-English text
Conversion uses your browser's built-in Unicode case mapping, so accented Latin characters, Greek and Cyrillic all convert correctly. Two known quirks exist in any tool that does this: Turkish dotted and dotless i do not round-trip correctly without locale-specific handling, and German ß uppercases to SS, which does not convert back. Neither has a clean general solution.
Frequently asked questions
How do I fix text I typed with caps lock on?
Paste it in and choose Sentence case. It lowercases everything and re-capitalises the start of each sentence. You will need to restore names and acronyms by hand, since that information was lost when they were typed in caps.
What is the difference between camelCase and PascalCase?
Only the first letter. camelCase starts lowercase ("userName"), PascalCase starts uppercase ("UserName"). By convention camelCase names variables and functions, PascalCase names classes, types and React components.
Which case should I use in a URL?
kebab-case, in lowercase. Search engines treat hyphens as word separators, and lowercase avoids duplicate-content problems on servers that treat URLs case-sensitively.
Does it work with accented and non-Latin characters?
Yes, for anything your browser can case-map, which covers accented Latin, Greek and Cyrillic. Turkish dotted/dotless i and German ß have known edge cases that no general-purpose converter handles correctly.
Is there a length limit?
No hard limit. Conversion is instant for anything up to a few hundred thousand characters. Very large documents may pause the tab briefly while converting.
Last updated September 19, 2026