Text Tools

Case Converter

A case converter rewrites text in a different capitalisation style — sentence case for prose, camelCase or snake_case for code. Two things usually go wrong elsewhere: converting getUserName to snake_case gives getusername because the existing word boundaries are ignored, and any accented or non-Latin character is silently deleted. Both are handled correctly here.

Runs entirely in your browser — your text is never uploaded.

Style

Headline style, minor words kept down

Input

Output

How to

How to use the Case Converter

1
Add your text
Type, paste, or drop in a .txt file. A list of names can be pasted whole — each line is converted separately rather than being run together.
2
Choose a style
Pick from prose styles like Title Case and Sentence case, or identifier styles like camelCase, snake_case, kebab-case and CONSTANT_CASE. Each button previews what it produces.
3
Check the result
The output appears beside your input. Existing word boundaries are respected, so getUserName becomes get_user_name rather than getusername.
4
Copy or download
Copy the result to the clipboard, download it as a text file, or swap it back into the input to chain another conversion.

Examples

Case Converter examples

An existing identifier

Input: XMLHttpRequest
Output: xml_http_request

The acronym and the word after it are separate. Converters that only split on spaces and underscores return xmlhttprequest, which is the single most common failure of this kind of tool.

Accented text

Input: café münchen
Output: caféMünchen

Stripping anything outside a-z would produce cafMnchen. Word splitting uses Unicode letter properties, so accents and non-Latin scripts survive the round trip.

A headline

Input: the lord of the rings
Output: The Lord of the Rings

Articles and short prepositions stay lowercase unless they open or close the title, which is what both Chicago and AP style require.

Why use it

What the Case Converter gives you

Understands existing casing

camelCase, PascalCase and acronym boundaries are detected, so converting between identifier styles works in both directions instead of only from spaced text.

No silent data loss

Accented letters, Cyrillic, Greek and CJK all pass through. Nothing is deleted for being outside the ASCII range.

Deliberate capitals respected

Title case leaves iPhone, macOS and NASA as they are rather than flattening them to Iphone, Macos and Nasa.

Lists stay lists

Identifier styles convert one line at a time, so a pasted column of field names comes back as a column, not a single run-on identifier.

Good to know

Case Converter limitations

Sentence case cannot restore proper nouns it has lowercased. Names already in lowercase stay that way, since no tool can tell a name from a common word without context.
Title case follows English minor-word conventions. Other languages capitalise differently and are only partly served.
Splitting an all-caps identifier like PARSEHTML is ambiguous — with no case boundary to read, it becomes one word.
Emoji and symbols are preserved but ignored when deciding word boundaries.

Summary

Case Converter in short

getUserName converts to get_user_name, not getusername.
Accented and non-Latin characters survive every conversion.
Title case keeps minor words down and leaves deliberate capitals like iPhone alone.
Sentence case repairs all-caps text while preserving genuine acronyms.
Conversion happens in your browser, so nothing is uploaded.

FAQ

Case Converter questions

Why do other converters turn getUserName into getusername?

They split only on spaces, hyphens and underscores, so an identifier with no separators looks like one word. Splitting also on the lowercase-to-uppercase boundary recovers the words, giving get_user_name.

How are acronyms handled in identifiers?

A run of capitals followed by a capitalised word is split between them, so XMLHttpRequest becomes xml_http_request rather than x_m_l_http_request. An acronym at the end, like parseHTML, stays whole.

Will accented characters be removed?

No. Word boundaries are found using Unicode letter properties instead of an a-to-z range, so café, naïve and Müller convert intact. Cyrillic, Greek, Arabic and CJK are preserved the same way.

Why are some words left lowercase in Title Case?

Articles, short conjunctions and short prepositions stay down in English titles unless they are the first or last word — which is why it is “The Lord of the Rings” and not “The Lord Of The Rings”.

Does Title Case ruin words like iPhone?

No. A word with a capital anywhere after the first letter, or one in all capitals, is treated as deliberately cased and left alone. iPhone, macOS, NASA and McDonald all survive.

How does Sentence case decide where sentences start?

It uses the same boundary detection as the word counter, so a full stop inside “Dr.”, “e.g.” or a price like 9.99 does not start a new sentence. Each real sentence gets its opening letter capitalised.

Can it fix text typed with caps lock on?

Yes. Sentence case detects that most of the text is uppercase and treats it as shouting, lowering everything before recapitalising each sentence. Short acronyms in otherwise normal text are still preserved.

What happens if I paste a list of names?

Identifier styles convert each line on its own, so twenty field names come back as twenty snake_case names. Prose styles read the whole text at once, since sentence detection needs the surrounding context.

Is the text I convert uploaded anywhere?

No. Every conversion is a string operation performed in the page. Internal field names or an unreleased product description never leave your browser.

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