Case Converter
Enter your text in the input area. Select the desired case from the options below, and the converted text will appear in the output area.
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How to use Case Converter
- 1
Enter your text
Type or paste the text you want to reformat into the Original Text box.
- 2
Select a case type
Choose from options such as UPPER CASE, lower case, Title Case, Sentence case, camelCase, snake_case, kebab-case, and more.
- 3
View the converted text
The reformatted text appears instantly in the Converted Text box, along with word, character, and line counts.
- 4
Copy the result
Click Copy to Clipboard to grab the converted text, or Clear Text to reset both fields.
A Practical Guide to Text Case Styles
Why letter case is a tool, not just a style
Capitalization carries meaning. The right case signals what a piece of text is: a heading, a sentence, a variable name, a URL slug, or a constant. Choosing it by hand is tedious and error-prone, especially for programming identifiers where one wrong character breaks the code. A case converter applies a consistent rule across an entire string in one step.
This tool covers the everyday writing cases plus the identifier styles developers use daily, and it shows live word, character, and line counts as you work. The sections below define each style with a worked example and explain when to reach for it, so you pick the case that fits the destination rather than guessing.
UPPERCASE and lowercase
UPPERCASE converts every letter to a capital: 'hello world' becomes 'HELLO WORLD.' It is useful for short labels, acronyms, legal headings, and anywhere you want emphasis, but long passages in all caps read slowly and feel like shouting, so use it sparingly. lowercase does the opposite, turning everything down: 'Hello World' becomes 'hello world.'
lowercase is handy for normalizing input before comparison, for a deliberately casual aesthetic, and for cleaning up text that arrived shouting. Both transforms only change casing, so converting to UPPERCASE and back to lowercase never alters the actual letters or word order, only their form. They are the simplest and most predictable of all the case styles.
Title Case and Sentence case
Title Case capitalizes the first letter of each major word, as in 'The Quick Brown Fox,' and is the convention for headlines, titles, and headings. Sentence case capitalizes only the first letter of the text (and, properly, proper nouns), as in 'The quick brown fox,' matching how ordinary prose is written. Choosing between them is mostly about whether you are writing a heading or a sentence.
Be aware that true title-case style guides have rules this kind of automated conversion cannot fully know: many guides leave short words like 'a,' 'an,' 'the,' 'and,' 'of,' and 'in' lowercase unless they start the title. An automatic Title Case capitalizes the start of each word as a sensible default, so for strict editorial style you may want to lowercase the minor words yourself afterward.
camelCase and PascalCase
camelCase joins words with no spaces and capitalizes each word except the first, producing 'helloWorld' or 'getUserName.' It is the dominant convention for variables and functions in languages like JavaScript and Java. PascalCase (also called UpperCamelCase) is the same idea but capitalizes the first word too, giving 'HelloWorld' or 'GetUserName.'
By convention PascalCase names classes, types, components, and constructors, while camelCase names the values and functions you use day to day. Keeping them distinct makes code self-documenting: a reader can tell a class from a variable at a glance. Both strip the spaces from your input, so 'user profile id' becomes 'userProfileId' or 'UserProfileId' respectively.
snake_case, kebab-case, and CONSTANT_CASE
These styles replace spaces with a separator instead of removing them. snake_case uses underscores and stays lowercase: 'user profile id' becomes 'user_profile_id,' the standard for variables and functions in Python and Ruby and for many database column names. kebab-case uses hyphens: 'user_profile_id' written as 'user-profile-id,' the right choice for URL slugs, CSS class names, and file names, since hyphens are URL- and filesystem-friendly.
CONSTANT_CASE is snake_case in all caps, as in 'MAX_RETRY_COUNT,' the long-standing convention for constants and environment variables across most languages. This tool also offers dot.case ('user.profile.id'), path/case ('user/profile/id'), and Header-Case ('User-Profile-Id'), which map neatly to config keys, file paths, and HTTP header names respectively.
The playful and utility cases
A few styles exist for effect or for transforming existing text rather than producing identifiers. iNVERSE cASE flips the case of every letter, so 'Hello' becomes 'hELLO,' which is useful for fixing text typed with Caps Lock on by accident. AlTeRnAtInG CaSe walks letter by letter alternating capitals, the classic 'mocking' look used in memes.
RaNDoM CasE capitalizes letters unpredictably for a chaotic, stylized appearance. These three differ from the others in that they read your existing letters and reassign case across them, so they are about styling words you already have rather than formatting an identifier. They are popular for social posts and captions where the look itself is the point.
Choosing the right case for the job
Match the case to the destination. Prose and body text use Sentence case; headings and titles use Title Case; loud short labels use UPPERCASE. In code, follow the target language's convention: camelCase or snake_case for variables and functions, PascalCase for classes and components, CONSTANT_CASE for constants, kebab-case for CSS classes and URL slugs, and dot.case or path/case for config keys and file paths.
Consistency matters more than any single preference. A codebase that mixes snake_case and camelCase for the same kind of name is harder to read and review. Pick the convention your framework or team expects and apply it uniformly. This converter makes that quick: paste a list of names, choose the target style, and copy the normalized result.
Common mistakes to watch for
Automatic case conversion does not understand meaning, so it can mangle things that need special handling. Acronyms are the classic example: Title Case may turn 'NASA' into 'Nasa,' and camelCase may render 'parseHTMLString' as 'parseHtmlString,' losing the intended capitalization. After converting, scan for acronyms and initialisms and fix them by hand.
Proper nouns can suffer the same way in Sentence case or lowercase, which will not know that 'paris' should stay 'Paris.' For identifier styles, also remember that the conversion changes word separators, so converting to snake_case and then to Title Case will not always recover your exact original spacing if the input had unusual punctuation. When the result has to be exact, convert, then proofread the edge cases rather than trusting the transform blindly.
Frequently asked questions
Which case styles are supported?
What is the difference between Title Case and Sentence case?
Can it produce programming-friendly formats?
Does converting change my actual words?
Is the tool free and private?
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