Free Case Converter: Change Text Case Online

Case Converter: Change the Case of Letters Online

Paste a text and click a case: the letters become capital or small at once. The tool knows the cases that programmers and webmasters use for names (Kebab-case, snake_case, camelCase and others), the usual cases of Word and Excel, the eight cases of the Notepad++ menu "Convert Case to" and the title style of English. It works in your browser, so the text is not sent anywhere. Cyrillic, Greek, accented and other national letters are handled too, not only English ones.

Cases for code

These modes take a name written in any style (my-var_name, myVarName, MY VAR NAME) and write it in the style you pick. Every line of the text is a separate name, so you can convert a whole list at once. Kebab-case is the first button and the one chosen when you open the page for the first time.

• Kebab-case (my-page-name): lowercase words joined by hyphens. It is also called lisp-case, dash-case and spinal-case; it is the same format. For a webmaster and a DevOps engineer it is one of the most common formats: addresses of pages, CSS classes, file names, Git branches, Docker image names, Kubernetes resource names (they must be lowercase with hyphens) and host names (a host name cannot have an underscore at all).
• snake_case: Python and Ruby variables, database columns, Rust and PHP function names, keys of JSON from many APIs.
• camelCase: JavaScript and Java variables, JSON keys. PascalCase: class names in C#, Java, TypeScript.
• CONSTANT_CASE: constants and environment variables. dot.case: configuration keys. Train-Case: HTTP headers such as Content-Type.

Kebab-case or snake_case in a URL?

For the address of a page choose hyphens. Here is the reason, and it is a good story. In the early years of search engines Google treated a hyphen (-) as a separator of words and an underscore (_) as a word joiner. The address best_hosting_vps was read as one long unclear word, besthostingvps, and best-hosting-vps as three words. Today the algorithms of Google are much smarter and understand both ways, but the official advice for URLs has not changed: use hyphens (kebab-case).

The rule of thumb: kebab-case for what the visitor and the search engine see (addresses, file names of images and pages, CSS classes, host names), snake_case for what the program sees (variables, database columns, parameters of the query in some frameworks). A double click on my_page selects the whole name in many editors, and on my-page only one word, which is a small advantage of snake_case when you edit code. To turn a title into a clean address with transliteration and a length limit use the slug generator; to see the parts of an address use the URL parser.

What the cases do

• Mother-In-Law (also called Proper Case) makes the first letter of every word a capital letter and all other letters small: mother-in-law becomes Mother-In-Law. The checkbox "A capital letter after a hyphen" controls the parts joined by a hyphen. The blend form changes only the first letters and leaves the rest as it was, so iPhone and McDonald are not damaged.
• UPPERCASE and lowercase change every letter. The German ß becomes SS, as it should.
• Sentence case makes the first letter of every sentence a capital letter (after a full stop, a question mark, an exclamation mark or an ellipsis) and the other letters small. It sees a quotation mark or a bracket before the first letter, and it keeps the English word I and forms like I'm in capitals. The blend form leaves all other letters alone, which is handy when the text has names and abbreviations. A box lets you start a sentence after every line break, which suits lists and subtitles.
• Title Case is the style of English headlines: every word starts with a capital letter, except the short words (a, the, of, to, in and similar) inside the title. The first and the last word and the word after a colon are always capitals.
• iNVERT cASE swaps the case of every letter. aLtErNaTiNg goes small, capital, small, capital. ranDOm CasE chooses by chance; click the button again to get another variant.

How to change the case in other programs

• Microsoft Word: select the text and press Shift + F3. Every press moves to the next case: Sentence case, lowercase, UPPERCASE. The button "Change Case" (Aa) on the Home tab has also "Capitalize Each Word" and "tOGGLE cASE".
• Excel and Google Sheets: the formulas =UPPER(A1), =LOWER(A1) and =PROPER(A1). Paste the result as values to replace the old text.
• Notepad++: menu Edit, Convert Case to; the shortcuts are Ctrl + Shift + U for capitals and Ctrl + U for small letters. This page has all the same modes and shows the result before you copy it.
• Python: text.upper(), text.lower(), text.title(), text.capitalize() and text.swapcase(). Note that title() does not like apostrophes: "don't".title() gives "Don'T".
• JavaScript: text.toUpperCase() and text.toLowerCase(); for the rules of a language use toLocaleUpperCase("tr").
• CSS: the property text-transform: uppercase | lowercase | capitalize changes only how the text looks, not the text itself.

Why the case of letters matters

• Passwords are case sensitive. Secret and secret are two different passwords. Many sites ask for at least one capital letter and one small letter. To make a strong password with the right mix of capitals, digits and symbols use the password generator.
• Logins and e-mail addresses are often compared without case, but file names, Linux paths and many API keys are not: Report.pdf and report.pdf are different files on a Linux server.
• Search and sorting. A program that compares text with the case on sees "Apple" and "apple" as different words. Make the case equal before you sort or remove duplicates, and then use the sort and shuffle lines tool.
• Reading. A text in capitals is read slower and looks like shouting. Convert it to Sentence case.

Related tools

To make a clean address from a title use the slug generator, to cut an address into parts the URL parser, and to encode or decode the %XX codes the URL decoder and encoder. A list of names can be sorted and cleaned of duplicates with the sort and shuffle lines tool, and a config or a JSON you have just renamed can be checked with the JSON validator and beautifier. To count the letters, words and lines of the result use the character counter. To write a text in bold, script or other fancy letters use the fancy text generator, and to shrink CSS or HTML after renaming the classes the HTML and CSS minifier.

Limitations

• Title Case follows the English rules and a short list of small words. For other languages use Sentence case.
• The names of people and places are not recognized: use the blend modes when the text has them, and check the result.
• In the cases for code, characters that are not letters or digits are dropped, and the words are found by the changes of case, spaces, hyphens and underscores.
• The text is not saved. The browser remembers only the mode and the boxes you chose.