How does it decide which words stay lowercase in title case?

It keeps a list of articles, conjunctions and short prepositions — a, an, the, and, of, in, to, for and similar — lowercase unless the word begins or ends the title, which is the common convention across English style guides.

Can it convert an existing camelCase name to snake_case?

Yes. Word boundaries are detected from capitalisation as well as from spaces and punctuation, so any of the ten cases converts to any other.

What happens to acronyms?

A run of capitals followed by a capitalised word is treated as one word, so getHTTPResponse splits into get, HTTP and Response. In camelCase and PascalCase output the acronym is normalised to Http, which is what most style guides prefer.

Does it handle accented characters?

Yes for upper and lower case, which follow Unicode rules. The programming cases strip characters outside A–Z and 0–9, because identifiers in most languages cannot contain them.

Case Converter

Switch text between sentence, title, camel, snake and kebab case.

Everything runs inside your browser. Your files never leave your device.

Input

Result

The result appears here as you type.

Ask about Case Converter

Questions about what this tool does, which option to pick, or what it can and cannot handle.

This is the one part of the site that uses a server. The question you type here is sent to an AI provider to be answered — your files and whatever you put in the tool above are not, and the assistant cannot see them. Answers are generated and can be wrong; the tool itself is not guessing.

About the Case Converter

Ten cases, one box. Sentence case and title case for prose; camelCase, PascalCase, snake_case, CONSTANT_CASE and kebab-case for code; plain upper and lower for when something arrived shouting.

The conversion is smarter than swapping characters, because turning “getHTTPResponseCode” into “get-http-response-code” requires knowing where the words are. The splitter handles the lowercase-to-uppercase boundary, the run of capitals followed by a capitalised word — which is what separates “HTTP” from “Response” — as well as spaces, hyphens and underscores. That means you can convert between naming conventions in either direction without first taking the identifier apart by hand.

Title case follows the convention most style guides share: articles, short prepositions and conjunctions stay lowercase unless they begin or end the title. "The Lord of the Rings", not "The Lord Of The Rings". Sentence case lowercases the whole string and then capitalises after each full stop, question mark or exclamation mark, which is the right behaviour for a heading that arrived in all capitals.

Everything runs in the browser as you type.

How to use it

1Paste or type your text into the input box.
2Pick the case you want from the dropdown — the result updates immediately.
3Copy the converted text, or switch cases to compare them.

Questions

How does it decide which words stay lowercase in title case?: It keeps a list of articles, conjunctions and short prepositions — a, an, the, and, of, in, to, for and similar — lowercase unless the word begins or ends the title, which is the common convention across English style guides.
Can it convert an existing camelCase name to snake_case?: Yes. Word boundaries are detected from capitalisation as well as from spaces and punctuation, so any of the ten cases converts to any other.
What happens to acronyms?: A run of capitals followed by a capitalised word is treated as one word, so getHTTPResponse splits into get, HTTP and Response. In camelCase and PascalCase output the acronym is normalised to Http, which is what most style guides prefer.
Does it handle accented characters?: Yes for upper and lower case, which follow Unicode rules. The programming cases strip characters outside A–Z and 0–9, because identifiers in most languages cannot contain them.