Case Converter: Uppercase, Title Case and camelCase

A case converter changes the capitalization of text without retyping it, turning "user first name" into "USER FIRST NAME", "User First Name" or "userFirstName" in one click. It is the quickest way to fix text typed with caps lock on, format a headline, or turn a phrase into a variable name.

Our free case converter handles eight styles: UPPERCASE, lowercase, Title Case, Sentence case, camelCase, snake_case, kebab-case and StudlyCase. This guide explains what each one is for, which style guides prefer which case, and how to get clean results.

Text case styles explained

Every row below starts from the same input, user first name, and shows what the converter returns.

Style	Result	Where it is used
UPPERCASE	USER FIRST NAME	Acronyms, short labels, warning signs
lowercase	user first name	Hashtags, email addresses, cleaning up data
Title Case	User First Name	Book, film and article titles; headlines
Sentence case	User first name	Headings in many style guides, buttons, menu items
camelCase	userFirstName	JavaScript variables and functions, JSON keys, PHP methods
snake_case	user_first_name	Python variables and functions, database column names
kebab-case	user-first-name	URLs, CSS class names, file names
StudlyCase (PascalCase)	UserFirstName	Class names in PHP, Python, Java and C#

Title case vs sentence case for headings

Writing style guides split on this. News and publishing guides use title case for headlines, but each has its own rules for small words. The Chicago Manual of Style lowercases articles, prepositions and coordinating conjunctions such as "and" and "or". AP style capitalizes prepositions and conjunctions of four letters or more. Technical style guides, including Google's developer documentation style guide and the Microsoft Writing Style Guide, recommend sentence case for headings because it is easier to read and to apply consistently.

Example: fixing a title

Start with the lord of the rings: the return of the king.

• Title Case gives The Lord of the Rings: The Return of the King. Small words such as "of" and "the" stay lowercase, except at the start of the title and after the colon.
• Sentence case gives The lord of the rings: the return of the king. Proper nouns like "Rings" still need a manual capital.

The converter follows simple rules, so it is a fast first pass. It capitalizes prepositions of four letters or more, such as "With" and "From", as AP style does. Chicago lowercases them, so adjust those by hand if you follow Chicago, and check proper nouns in Sentence case.

Programming case conventions

In code, case styles are more than taste. Many languages have written conventions, and linters flag names that break them.

• Python (PEP 8): snake_case for functions and variables, CapWords (StudlyCase) for classes, and UPPER_CASE with underscores for constants.
• PHP (PSR-1): class names in StudlyCaps, method names in camelCase, and class constants in uppercase with underscores.
• JavaScript: camelCase for variables and functions and PascalCase for classes are the widespread convention.
• CSS and URLs: kebab-case, as in .nav-item or /pricing-plans.

To build an uppercase constant name such as CUSTOMER_ORDER_TOTAL, convert customer order total to snake_case first, then click UPPERCASE.

How to use the Case Converter

1. Open the Case Converter.
2. Type or paste your text into the Text box. It holds up to 100,000 characters.
3. Click a style button: UPPERCASE, lowercase, Title Case, Sentence case, camelCase, snake_case, kebab-case or StudlyCase. The text in the box is replaced with the converted version.
4. Click Copy to put the result on your clipboard, or Clear to empty the box.

Each conversion works on the current contents of the box, so keep a copy of your original text if you want to compare several styles.

Tips and common mistakes

• Type acronyms and brand names the way they should look. Title Case keeps any word with a capital after its first letter as typed, so "NASA" and "iPhone" stay as they are. Text typed all in capitals is converted as if it were lowercase, so there "NASA" becomes "Nasa".
• Check names after Sentence case. Sentence case lowercases the whole text, then capitalizes the first letter of each sentence and each line, and the word "I". Names, places and acronyms such as "NASA" come out in lowercase, so fix them by hand.
• Code styles split words for you. camelCase, snake_case, kebab-case and StudlyCase start a new word at spaces, punctuation and capitals, keep acronyms whole and drop the punctuation. So "Customer: ID" becomes customer_id and "HTTPServer" becomes http_server. For URLs, the slug generator also turns accented letters into plain ones.
• Convert a whole list at once. camelCase, snake_case, kebab-case and StudlyCase convert each line on its own and keep the line breaks, so a list of column names becomes a list of identifiers.
• Avoid long passages in capitals. All-caps text is harder to scan and reads as shouting in emails and messages. Keep UPPERCASE for short labels.

The duplicate line remover drops repeated lines from lists and sorts what's left, and the word counter checks that a converted headline still fits its limit. For URLs specifically, our guide to SEO-friendly URL slugs explains why kebab-case is the standard.

Frequently asked questions

What is title case?

Title case capitalizes the main words of a title or heading. Style guides such as Chicago and AP keep certain short words lowercase. Our converter keeps articles, short conjunctions and short prepositions such as "the", "and" and "of" lowercase unless they start or end a line or follow a colon.

What is the difference between camelCase and PascalCase?

Both join words without spaces and capitalize each new word. camelCase starts with a lowercase letter (userFirstName); PascalCase, also called StudlyCase, starts with a capital (UserFirstName).

What is snake_case used for?

snake_case joins lowercase words with underscores, as in user_first_name. Python uses it for variables and functions, and it is common for database column names.

What is kebab-case?

kebab-case joins lowercase words with hyphens, as in user-first-name. It is the standard for URL slugs and CSS class names.

How do I change text from uppercase to lowercase without retyping?

Paste the text into a case converter and click lowercase. For normal sentence capitalization instead, click Sentence case: it lowercases the text and capitalizes the start of each sentence.

Should headings use title case or sentence case?

Either is correct if you apply it consistently. Publishing and news guides often use title case for headlines, while Google's and Microsoft's documentation style guides recommend sentence case.