Case Converter
Switch text between UPPERCASE, lowercase, Title Case, Sentence case and the programming cases — camelCase, PascalCase, snake_case, kebab-case and CONSTANT_CASE.
How it works
The prose cases work on the text as written: Title Case capitalises each word but leaves short joining words such as “of”, “the” and “and” lowercase unless they open the sentence, which is what most style guides ask for.
The programming cases first split the text into words — including at the boundaries inside an existing camelCase string — then rejoin them in the target style. That means you can paste `getUserName` and get `get_user_name` without editing it by hand first.
The formula
Title Case
capitalise each word; keep a, an, the, of, and… lowercase mid-sentence
camelCase
split into words → first word lowercase → capitalise the rest → join
snake_case
split into words → lowercase → join with _
Worked examples
| Scenario | Working | Result |
|---|---|---|
| “the lord of the rings” | Title Case | The Lord of the Rings |
| “user first name” | camelCase | userFirstName |
| “getUserName” | kebab-case | get-user-name |
When you'd use it
- Fixing a heading that was typed in caps lock
- Renaming variables between languages with different conventions
- Turning a spreadsheet column header into a database field name
- Cleaning up copy pasted from a design file
Common questions
Why does Title Case leave some words lowercase?
Because that is what style guides specify. Articles, short prepositions and conjunctions stay lowercase unless they begin the title — “The Lord of the Rings”, not “The Lord Of The Rings”.
Can it convert an existing camelCase name?
Yes. The programming cases detect word boundaries inside camelCase and PascalCase, so `getUserName` converts cleanly to `get_user_name` or `get-user-name`.
Is my text uploaded anywhere?
No. The whole tool runs in your browser, so what you paste never leaves your device. That matters when the text is a draft, a transcript or anything covered by an NDA.