Case Converter

Convert text between UPPERCASE, lowercase, Title Case, camelCase, snake_case, and more. Free and instant.

Free to use. Runs in your browser.

Paste your text and click any case button to convert instantly. Supports 10 different case styles.

Conversions happen in your browser, nothing is uploaded.

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Why Text Case Matters More Than You Think

Text case isn't just about aesthetics, it's about conventions, readability, and consistency. In programming, the wrong case breaks your code: a variable named "userName" is completely different from "username" in case-sensitive languages. In writing, case signals intent: ALL CAPS reads as shouting, Title Case looks professional, and sentence case feels natural.

Naming conventions exist for a reason. JavaScript uses camelCase for variables and PascalCase for classes. Python uses snake_case for functions and SCREAMING_SNAKE_CASE for constants. CSS uses kebab-case for properties. Mixing conventions makes code harder to read and maintain.

This converter handles all the common cases instantly. Paste your text, pick the target case, and copy the result. It handles edge cases like acronyms, numbers, and punctuation that trip up manual conversion.

Case Types Explained

Case	Example	Used In
camelCase	myVariableName	JavaScript/TypeScript variables, Java methods
PascalCase	MyVariableName	React components, C# classes, TypeScript types
snake_case	my_variable_name	Python, Ruby, Rust, database columns
SCREAMING_SNAKE	MY_VARIABLE_NAME	Constants in most languages, environment variables
kebab-case	my-variable-name	CSS properties, HTML attributes, URL slugs
Title Case	My Variable Name	Headings, titles, UI labels
Sentence case	My variable name	Paragraphs, descriptions, normal text
UPPERCASE	MY VARIABLE NAME	Emphasis, headers, abbreviations
lowercase	my variable name	Normalisation, search, comparison
Toggle Case	mY vARIABLE nAME	Stylistic effect, inverting existing case

What this means for you: When converting between cases, the tool splits your text into words first, then reassembles with the target convention. This means "myVariableName" correctly converts to "my_variable_name", it recognises word boundaries in any source format.

Naming Convention Best Practices

Be consistent within a project

Pick one convention per context and stick to it. If your API returns snake_case, use snake_case for those fields throughout. Mixing conventions in the same file is a code smell.

Follow language conventions

Every language has established norms. Python's PEP 8 says snake_case. JavaScript's community prefers camelCase. Fighting these conventions makes your code harder for other developers to read.

Handle acronyms carefully

Is it "XMLParser" or "XmlParser"? "getHTTPResponse" or "getHttpResponse"? Most style guides prefer treating acronyms as words: XmlParser, getHttpResponse. It's more readable and converts between cases more predictably.

Use case to signal intent

SCREAMING_SNAKE signals "don't change this" (constants). PascalCase signals "this is a class/component." camelCase signals "this is a variable/function." The case itself communicates meaning to other developers.

Case Conversion in Code

Most languages have built-in methods for basic case changes, but converting between naming conventions (camelCase → snake_case) usually requires a library or custom function:

Language	Basic Case	Naming Convention
JavaScript	str.toLowerCase()	lodash: _.camelCase(str)
Python	str.upper() / str.title()	inflection.underscore(str)
Ruby	str.downcase / str.upcase	str.underscore / str.camelize
PHP	strtolower($str)	Str::camel($str) (Laravel)
SQL	UPPER(col) / LOWER(col)	No built-in support

What this means for you: For a one-off conversion, paste your text above and copy the result. For bulk transformations in a codebase, use your editor's search and replace with regex, or a dedicated rename refactoring tool.

The Same Phrase in Every Case

Seeing one phrase run through every style makes the differences obvious. Here is "User Profile Settings" in each of the ten conversions this tool offers.

Style	Result
UPPERCASE	USER PROFILE SETTINGS
lowercase	user profile settings
Title Case	User Profile Settings
Sentence case	User profile settings
camelCase	userProfileSettings
PascalCase	UserProfileSettings
snake_case	user_profile_settings
kebab-case	user-profile-settings
CONSTANT_CASE	USER_PROFILE_SETTINGS
tOGGLE cASE	uSER pROFILE sETTINGS

Acronyms, Numbers, and Symbols

Conversions between naming conventions split your text into words first, and a few rules decide where those word boundaries fall. Knowing them helps you predict the output.

Input	snake_case result	What happened
XMLParser	x_m_l_parser	A run of capitals splits letter by letter
XmlParser	xml_parser	Acronym written as one capitalised word
user2name	user2name	Digits stay attached, no new word
hello-world_test	hello_world_test	Mixed separators collapse to one

The practical takeaway: write acronyms as a single capitalised word (Xml, Http, Api) and the conversions stay clean and predictable across every style.

Title Case vs Sentence Case

These two trip people up most. This tool's Title Case capitalises the first letter of every word, which is ideal for UI labels, button text, and short headings where a clean, even look matters.

Editorial title case in the AP and Chicago styles is stricter: it keeps short words such as "a", "an", "the", "of", "in", and "and" lowercase unless they begin or end the title. So "the lord of the rings" becomes "The Lord of the Rings", not "The Lord Of The Rings". If you are following a house style guide, expect to lowercase those small words by hand after converting.

Sentence case capitalises only the first word of the text and the first word after each full stop, question mark, or exclamation mark. It is the most natural choice for body copy, descriptions, and notifications, and it reads far more calmly than Title Case in a long sentence.

Case Sensitivity Gotchas

Getting the case right is not just style. In several places, the wrong case quietly breaks things, so it pays to know where case actually matters.

JSON keys are case-sensitive: name and Name are two different keys.
URLs: the domain is never case-sensitive, but the path usually is on Linux servers, so /About and /about can be two different pages.
Filesystems: Linux is case-sensitive, while macOS and Windows are usually case-insensitive but preserve the case you typed. Code that works on a laptop can fail on a Linux server over a single capital.
SQL: whether identifiers and text comparisons are case-sensitive depends on the database and its collation, so never assume "Smith" and "smith" match.
CSS and HTML: tag names are case-insensitive, but class names and IDs are case-sensitive, so .Card will not match .card.

Choosing the Right Case

Variables and functions: camelCase in JavaScript, Java, and Swift; snake_case in Python, Ruby, and Rust.
Classes, components, and types: PascalCase almost everywhere, including React components and C# classes.
Constants and environment variables: CONSTANT_CASE to signal a value that should not change.
URLs, CSS, and file names: kebab-case, which reads well in a web address and avoids case-sensitivity surprises.
Headings and body text: Title Case for short headings, Sentence case for anything longer than a few words.

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How to use this tool

Paste or type your text into the input box

Click the desired case style button

Copy the converted text to your clipboard

Common uses

Converting headings to Title Case for blog posts
Generating UPPER CASE text for design mockups
Creating camelCase or snake_case variable names
Cleaning up ALL CAPS text from legacy data

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Frequently Asked Questions

What case conversions are supported?

Ten case styles: UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, and Toggle Case. Each follows the standard convention used in programming and writing.

Is my text stored or sent anywhere?

No. All conversions happen locally in your browser using JavaScript string methods. Your text never leaves your device, nothing is transmitted to any server.

What's the difference between camelCase and PascalCase?

camelCase starts with a lowercase letter (myVariableName). PascalCase starts with uppercase (MyVariableName). In most conventions, camelCase is for variables and functions, PascalCase is for classes and React components.

When should I use snake_case vs kebab-case?

snake_case is the convention in Python, Ruby, Rust, and SQL (column_names). kebab-case is used in CSS properties, HTML attributes, and URL slugs. They're functionally similar but belong to different ecosystems.

What is CONSTANT_CASE?

Also called SCREAMING_SNAKE_CASE, all uppercase with underscores between words. Used for constants in almost every language: MAX_RETRIES, API_BASE_URL, DEFAULT_TIMEOUT. It signals 'this value should not change.'

How does the tool handle acronyms?

Each capital letter starts a new word, so a run of capitals splits letter by letter: 'XMLParser' becomes 'x_m_l_parser' in snake_case. For cleaner output, write the acronym as a single capitalised word, so 'XmlParser' becomes 'xml_parser'.

Can I convert between programming naming conventions?

Yes, that's one of the primary use cases. Paste a variable name in any format and convert it to another. 'getUserName' converts to 'get_user_name' (snake_case), 'get-user-name' (kebab-case), or 'GetUserName' (PascalCase).

What is Toggle Case used for?

Toggle case inverts every character's case: 'Hello World' becomes 'hELLO wORLD'. It's mainly used for stylistic effects or mocking text. Not commonly used in programming.

Does Title Case handle articles and prepositions?

This tool capitalises the first letter of every word. Strict title case (AP/Chicago style) would leave words like 'a', 'the', 'in', 'of' lowercase unless they start the title. For strict title case, manual adjustment may be needed.

Can I convert entire paragraphs?

Yes. UPPERCASE, lowercase, Title Case, Sentence case, and Toggle Case work on any text length. Programming cases (camelCase, snake_case, etc.) work best on individual names or short phrases, they'll concatenate an entire paragraph into one long identifier.

How does Sentence case work?

Sentence case capitalises the first letter of each sentence and the first character of the text. Everything else becomes lowercase. It recognises sentence boundaries at periods, exclamation marks, and question marks.

Is there a keyboard shortcut?

This tool doesn't have built-in shortcuts, but most code editors do: VS Code has 'Transform to Uppercase/Lowercase/Title Case' in the command palette (Ctrl+Shift+P). For a quick one-off conversion, paste your text above and click a style.

Results are for general informational purposes only and should be checked before use. They are not professional advice. See our Disclaimer and Terms of Service.