ToolBrainy

Case Converter

Switch text between UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case and kebab-case — one click, nothing uploaded.

About this tool

The Case Converter transforms text between eight different formats with a single click. Unlike word processor tools that only offer basic uppercase or lowercase, this one covers the programming formats — camelCase, PascalCase, snake_case, and kebab-case — which are tricky to apply manually across long identifiers or large blocks of text.

Each format has a clear purpose. UPPERCASE is used for constants in code, acronyms, and emphasis. lowercase gives a casual, approachable feel popular in social media and modern branding. Title Case is the standard for blog headings, book titles, and product names. Sentence case is how most regular writing looks — only the first letter of the sentence capitalised. camelCase and PascalCase are used for variable and class names in JavaScript, Java, and C#. snake_case is the convention in Python, Ruby, and SQL. kebab-case shows up in URLs, CSS class names, and HTML attributes.

How to use

1
Paste your text

Type or paste anything — a word, a sentence, a list of variable names, or an entire paragraph. The converter handles any length.

2
Click a format

Press the case button you need. The text changes immediately. You can switch between formats as many times as you like without repasting.

3
Copy and use

Hit "Copy result" to put the converted text on your clipboard, then paste it wherever you need it. Or click "Clear" to start fresh.

Why use it

Private by design

Your text never leaves your browser, nothing is uploaded.

8 formats, one click

Every common text case is a single tap away.

Real-time

Edit your text and the result updates as you type.

100% free

No signup, no limits and no watermarks, ever.

When each format is used

camelCase & PascalCase for code

JavaScript functions and variables use camelCase: getUserName, totalPrice. Classes and constructors use PascalCase: UserProfile, OrderManager. Java and C# follow the same conventions.

snake_case for Python & databases

Python variables, functions, and database column names follow snake_case: user_first_name, order_total. SQL table and column names are almost always snake_case too.

kebab-case for URLs & CSS

URL slugs and CSS class names use hyphens: main-navigation, hero-section, product-card. HTML data attributes and some config file keys also follow this pattern.

Title Case for headings & titles

Blog post headings, book titles, product names, and article titles follow Title Case. Paste a list of your headings and apply it in one click instead of fixing each one by hand.

Fix accidental CAPS LOCK

Paste text typed with caps lock on and click "Sentence case" or "lower case" to correct it instantly — no retyping needed, no matter how long the passage.

Normalise data exports

CSV files and database exports often have mixed capitalisation — some rows in UPPER CASE, others in lower case or Title Case. Paste the content and standardise it before importing.

Examples

Take the phrase quick brown fox and see where it lands in each format. It's the quickest way to work out which button you actually need.

UPPERCASE: QUICK BROWN FOX  ·  lowercase: quick brown fox  ·  Title Case: Quick Brown Fox  ·  Sentence case: Quick brown fox

camelCase: quickBrownFox  ·  PascalCase: QuickBrownFox  ·  snake_case: quick_brown_fox  ·  kebab-case: quick-brown-fox

A real one: paste a heading like 10 Tips for Faster Websites, click kebab-case, and you get 10-tips-for-faster-websites — a clean URL slug ready to drop into your CMS.

Common mistakes to avoid

Using Title Case for code names

Identifiers can't contain spaces. If you need a variable or class name, reach for camelCase, PascalCase, or snake_case — Title Case just leaves the spaces in and won't run.

Overlooking acronyms in camelCase

Converting "user ID" gives userId, not userID. If your team keeps acronyms uppercase, check names like ID, URL, and API after converting.

Applying Title Case to whole sentences

Title Case is for headings, not body copy. Capitalising Every Word In A Paragraph is genuinely hard to read. Use Sentence case for anything longer than a heading.

Swapping underscores and hyphens

snake_case and kebab-case are not interchangeable. A CSS class needs a hyphen; a Python variable needs an underscore. Mixing them breaks the selector or the code.

Tips for cleaner text

Pick one convention per project

Whatever casing your codebase already uses, stick with it. Consistency matters more than which style is "correct" — mixed conventions are what slow down reviews.

Convert headings in bulk

Rather than fixing capitalisation heading by heading, paste the whole list, apply Title Case once, and copy it all back. The same trick turns a list of titles into URL slugs.

Skim the result before pasting

Casing tools follow rules, not judgement. Glance over the output for proper nouns, brand names, and acronyms that might still need a manual tweak.

Normalise messy exports first

When cleaning a data export, lowercase everything first, then apply the format you want. Starting from one known state gives far more predictable results.

Frequently asked questions

Is the case converter free to use?

Yes, completely free. No account, no usage cap, and no watermarks. There's also no file size limit — paste as much text as you need.

Is my text stored or shared?

No. Conversions happen entirely in your browser using JavaScript. Your text is never sent to a server, never logged, and never stored anywhere. You could even disconnect from the internet after loading the page and it would still work.

What's the difference between camelCase and PascalCase?

Both join words without spaces, but camelCase starts with a lowercase letter (myVariableName) while PascalCase starts with an uppercase letter (MyVariableName). In JavaScript, you'd typically use camelCase for variables and functions, and PascalCase for class and constructor names.

When should I use snake_case vs kebab-case?

Use snake_case (my_variable) for Python variables, function names, database columns, and file names in Python projects. Use kebab-case (my-variable) for CSS class names, HTML IDs, URL slugs, and JSON keys in some APIs. Snake_case uses underscores; kebab-case uses hyphens.

Does Title Case capitalise every word?

Title Case capitalises the first letter of each word. For the most part, this tool follows that rule for all words. Note that formal style guides (AP, Chicago) make exceptions for short prepositions and articles like "a", "an", "the", "in", "of" — but those nuances vary by publication.

Are punctuation and numbers preserved?

Yes. Only the letter casing is changed. Punctuation, numbers, symbols, and spacing all remain exactly as they were in your original text.

Can I convert multiple lines at once?

Yes. Paste an entire document, a list of headings, or hundreds of variable names and convert them all in one click. The tool handles any amount of text with no limit.

What's the difference between Title Case and Sentence case?

Title Case capitalises the first letter of every main word — good for headings and titles. Sentence case capitalises only the first letter of the sentence, like normal writing. Use Title Case for a blog heading, Sentence case for the paragraph underneath it.

Does it keep proper nouns and brand names capitalised?

Only where the format allows it. Lowercase and snake_case, for example, will turn "London" into "london". The tool applies rules rather than judgement, so scan the result and fix any names that need to stay capitalised.

Does it handle accented or non-English letters?

Yes. Characters like é, ñ, ü, and ç convert correctly between upper and lower case, so text in French, Spanish, German, and similar languages is handled properly.

Does converting change my original text or just the copy?

It changes what's shown in the tool, but nothing on your device or in your documents. Your source file stays untouched until you copy the result and paste it somewhere yourself.

Can I use it on my phone?

Yes. The converter is fully responsive, so paste, convert, and copy all work the same on a phone or tablet as they do on a desktop.

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