Case Converter: Title Case, Sentence Case, camelCase and More

Paste text and every style appears at once, each with its own copy button. The text styles are UPPER CASE, lower case, Title Case, Sentence case, Capitalize Each Word, aLtErNaTiNg and iNVERT cASE. The code styles are camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE and dot.case. Line breaks are kept, so you can convert a whole document. Code styles treat each line as its own identifier, which turns a pasted list of column names into a list of variable names in one go.

The code styles first split the input into words, and that step is the difficult part. fooBar, foo_bar, FOO-BAR and "foo bar" all become the words foo and bar. A run of capitals followed by a capitalised word is split before the last capital, so HTTPServer becomes HTTP and Server. Digits stay with the word before them (version2 is one word) and split off in front of a capitalised word (v2Beta becomes v2 and Beta).

Capitalising every word is not title case. Chicago style keeps articles, coordinating conjunctions and all prepositions in lower case, whatever their length; AP and APA keep only words of three letters or fewer in lower case and capitalise everything of four letters or more. Both always capitalise the first and last word and the first word after a colon, and capitalise both halves of most hyphenated compounds (Well-Known) while leaving small words inside them in lower case (Mother-in-Law). Pick the style in the options.

Acronyms and brand spellings with a capital inside the word (NASA, iPhone, JavaScript) are left as typed, and URLs and email addresses are not touched. If the whole text arrives in capitals, it is normalised first. One honest limit: a tool cannot tell a preposition from an adverb ("Look Up", "Turn Over"), so it applies the word list, and you should still read a headline once before you publish it.

Conversion uses the Unicode case mappings built into your browser, so accents, Greek and Cyrillic work, and ß becomes SS in upper case as the standard requires. Turkish and Azeri have a dotted and a dotless i, so "istanbul" must become "İSTANBUL" and not "ISTANBUL"; choose the Turkish option to get the right result. Scripts without case, such as Arabic, Urdu, Chinese and emoji, pass through unchanged.

Large texts are converted one style at a time so typing never freezes, and the output panels show a preview while the copy button always copies the full result.