Case Converter

How it works

Pick a mode, choose the casing rules and the converted text appears next to your input. Copy it with one click.

UPPERCASE and lowercase change every letter of the text. Digits, punctuation, spaces and emoji stay as they are.

Sentence case lower-cases the whole text, then capitalises the first letter of the text and of every sentence. A sentence starts after a full stop, exclamation mark, question mark or ellipsis (a closing quote or bracket may follow) and a space, and after every line break. A sentence that starts with a digit keeps it and leaves the next letter alone.

Capitalize Each Word lower-cases the text and then capitalises the first letter of every word. Words follow the Unicode word-boundary rules (UAX #29): an apostrophe stays inside a word, a hyphen starts a new one.

Casing rules. Letters are converted with the language rules of the chosen language, which defaults to the page language. This matters for the letter i, for German ß and for final Greek sigma. The converter uses the browser's built-in toLocaleUpperCase and toLocaleLowerCase, which follow the Unicode special casing tables.

Examples

The English rule on a Turkish text. In the fourth row the English rule lower-cases the "I" of IŞIK to a plain "i", so "ışık" becomes "işik", and the "İ" of İSTANBUL turns into an "i" plus a combining dot. Both are wrong for Turkish. The same words under the Turkish rule are correct, which is why the selector exists.

Names are not recognised. "merhaba! ben ali." in Sentence case becomes "Merhaba! Ben ali." The tool does not know that "ali" is a name. Capitalise names by hand after converting, or use Capitalize Each Word when every word should start with a capital.

Things to watch for

• Choose the language of the text, not of the page. A Turkish text pasted on the English page needs the Turkish rule, and an English text pasted on the Turkish page needs English. The selector starts on the page language and does not detect the language of your text.
• Case conversion can change length. "ß" becomes two letters in uppercase, and "İ" in lowercase outside Turkish becomes two code points. If you are fitting a character limit, count the result, not the original.
• Conversion is not always reversible. "STRASSE" does not return to "Straße", and an all-caps text loses the information about which letters were originally capitals. Keep the original if you may need it.
• Sentence case is a mechanical rule. Proper nouns, acronyms and the English pronoun "I" come out in lower case, and abbreviations such as "e.g." are treated as the end of a sentence. Read the result before using it.
• Capitalize Each Word is not a style guide. If a publisher asks for title case, small words such as "of", "and" and "the" stay in lower case there; this mode capitalises them too.
• Over the limit nothing is converted. Above 500,000 characters the result stays empty and an error appears under the field; shorten the text or convert it in parts.
• Numbered lists get capitals. In Sentence case "1. item" becomes "1. Item", because a full stop followed by a space starts a sentence. Decimals such as "3.5 kg" are left alone.
• Everything runs in your browser. The text is not sent to a server and is not stored.