The Case Converter changes the capital letters in any text in one click. Paste your text into the box at the top of this page, choose a case such as UPPER CASE, lower case, Sentence case, or Title Case, and the converted text appears straight away, ready to copy or download. It's free, there's nothing to install, and your text never leaves your browser.
Retyping a paragraph because Caps Lock was on, or capitalising every word of a heading by hand, takes longer than it should. A text case converter does it in one step and gets it right every time, whether you need to convert uppercase to lowercase, lowercase to uppercase, or turn a list of phrases into variable names.
Cases for everyday writing
The first seven options change capital and small letters without touching anything else. Spaces, punctuation, numbers, and line breaks stay exactly where they were:
- Sentence case: a capital at the start of each sentence and small letters everywhere else, like
The quick brown fox. It jumps.Use it for normal text and to repair text typed in capitals. - lower case: every letter small, like
the quick brown fox. Handy for email addresses, tags, and a casual look. - UPPER CASE: every letter a capital, like
THE QUICK BROWN FOX. Good for short headings, labels, and signs; long passages in capitals are hard to read. - Capitalized Case: every word starts with a capital, small words included, like
The Quick Brown Fox. It's the quickest way to capitalize each word. - Title Case: main words start with a capital and short words stay small, like
The Lord of the Rings. - aLtErNaTiNg cAsE: small and capital letters take turns, like
tHe QuIcK bRoWn FoX, the style of mocking memes. - iNVERSE cASE: every capital becomes small and every small letter a capital, which undoes text typed with Shift and Caps Lock mixed up.
How to fix text typed with Caps Lock on
It happens to everyone: you look up and a whole paragraph is in capitals. Paste it into the box and choose Sentence case. Every letter becomes small again, and each sentence starts with a capital. A full stop, question mark, or exclamation mark followed by a space starts a new sentence, and so does a new line, while abbreviations such as e.g., i.e., Mr., and Dr. don't.
If you pressed Shift while Caps Lock was on, the text looks like hELLO, MY NAME IS aNNA. Choose iNVERSE cASE and every letter flips back: Hello, my name is Anna.
Sentence case can't tell a name from an ordinary word, so Paris and Maria become paris and maria unless they start a sentence. Check names and places before you copy. Acronyms such as NASA can keep their capitals, as explained further down.
How Title Case decides which words get a capital
Title Case follows rules that most English style guides share. The first and last words of each line always start with a capital, and so does a word that follows a colon, a dash, or a full stop. In between, articles (a, an, the), coordinating conjunctions (and, but, or, nor, so, yet, for), and short prepositions (as, at, by, in, of, on, to, per, via) stay small. Every other word gets a capital.
That's why the lord of the rings becomes The Lord of the Rings, while Capitalized Case gives The Lord Of The Rings. Style guides such as AP and Chicago disagree about a few words, for example whether with and from take a capital, so check headlines that must follow one guide exactly.
Keep acronyms such as NASA and PDF
With Keep words in capitals, such as NASA or PDF turned on, Sentence case, Capitalized Case, and Title Case leave words written in two or more capitals alone. NASA, USA, PDFs, and MP3 stay as they are, so i sent the PDF to NASA becomes I sent the PDF to NASA in Sentence case.
When almost all of the text is in capitals, the converter treats it as Caps Lock text and converts every word, because there's no way to tell an acronym from a shouted word. Turn the option off to convert acronyms everywhere. Brand names with mixed capitals, such as iPhone and eBay, don't count as acronyms, so check them after converting.
Change case in other languages
Capital and small letters are changed for every alphabet that has them, including accented Latin letters, Greek, Cyrillic, and Armenian. The converter uses your browser's language rules, so Turkish dotted and dotless i work when your browser is set to Turkish. Scripts without capitals, such as Chinese, Arabic, and Hindi, are left as they are.
In Sentence case, Write “i” on its own as “I” (English) turns the English pronoun into a capital. Turn it off for Italian, Catalan, and other languages where i is an ordinary word.
camelCase, snake_case, and other programming cases
The last six options turn each line into a name for code. Spaces, punctuation, and symbols split the words, and so do existing capitals. The words are then joined in the style you pick:
- camelCase:
firstName, for JavaScript and Java variables and functions. - PascalCase:
FirstName, for classes, types, and components. - snake_case:
first_name, for Python, Ruby, and database columns. - CONSTANT_CASE:
FIRST_NAME, for constants and environment variables. - kebab-case:
first-name, for web addresses, CSS classes, and file names. - dot.case:
first.name, for settings keys.
Put one phrase on each line to convert a whole list of fields at once. XMLHttpRequest becomes xml_http_request in snake_case, and apostrophes are dropped, so don't becomes dont.
Copy, download, or keep converting
Select Copy to put the result on your clipboard, or Download .txt to save it as converted-text.txt. Under the result, the tool counts its characters, words, and lines. Use as input makes the converted text your new text, so you can apply several changes in a row, and Ctrl+Z (⌘Z on a Mac) in the box brings back what was there before.
To change the case of only part of a document, open it in the online text editor, select that part, and use Transform. To write text backwards or upside down, try the text reverser. For bold, cursive, and other styled letters, use the fancy text generator.
Free and private
The case converter is free, needs no account, and works in any modern browser on Windows, Mac, Chromebook, iPhone, iPad, and Android. Converting happens on your device: your text is never uploaded or saved, so it's gone when you close the page. The privacy page explains what the website itself collects.
Ready? Paste your text in the box above and pick a case.