Case Converter — camelCase, snake

Renaming things is half the job

Every codebase is an argument about casing. JSON from an API arrives in snake_case, your TypeScript wants camelCase, the database columns are lower_snake, the environment variables are CONSTANT_CASE, the CSS classes are kebab-case, and the React components are PascalCase. Converting between them by hand is the kind of tedious that produces typos.

Acronyms are where converters break

The interesting problem is not fooBar — it is parseHTTPResponse. A naive converter that splits before every capital letter gives you parse_h_t_t_p_response. This one treats a run of capitals as a single word, with the final capital starting a new word when a lowercase letter follows it, so you get parse_http_response. The same rule handles XMLHttpRequest, parseURLPath and IOError correctly.

Digits are treated as part of the word they touch, so base64Encode stays base64_encode rather than splitting into base_64_encode.

Whole lists at once

Each line converts independently, so you can paste a column of database columns, a list of API fields or a set of identifiers and get the entire set back in one go. That is usually the actual task — nobody converts one identifier.

Kebab-case against slug

They look identical until the input has punctuation. Kebab-case only changes separators and casing; a slug additionally strips accents, removes punctuation and collapses anything non-alphanumeric so the result is safe in a URL. Café & Bar (2026) becomes café-&-bar-(2026) as kebab and cafe-bar-2026 as a slug. Both are offered because the right one depends on whether the output is an identifier or an address.

Questions people actually ask

How are acronyms handled?

`parseHTTPResponse` splits as parse / HTTP / Response rather than parse / h / t / t / p, so it becomes `parse_http_response` instead of a string of single letters. Runs of capitals are treated as one word, with the last capital starting a new word when a lowercase letter follows.

Can I convert a whole list at once?

Yes. Every line is converted independently, so you can paste a column of column names or identifiers and get the whole set back.

What is the difference between kebab-case and a slug?

Kebab-case only changes separators and casing. A slug additionally strips accents and punctuation and collapses anything non-alphanumeric, so it is safe in a URL. Both are offered because they differ exactly when the input has interesting characters in it.