Is the Case Converter free to use?

Yes, the Case Converter is completely free with no usage limits. You can convert as much text as you need without creating an account or paying anything.

Does the tool work with non-English text?

Yes, the Case Converter works with text in any language that has uppercase and lowercase forms. For languages without case distinctions, formatting options like snake_case and kebab-case still apply.

Is my text data safe when using this tool?

Absolutely. All text conversion happens locally in your browser. Your data is never sent to any server, making it completely private and secure.

How do I convert camelCase to snake_case?

Paste the identifier and pick snake_case; helloWorldExample becomes hello_world_example. The converter finds the boundary at each lowercase-to-uppercase transition, so you do not need to add spaces first.

Does it handle acronyms like XMLHttpRequest?

Yes. A run of capitals followed by a capitalised word is treated as one word, so XMLHttpRequest becomes xml_http_request rather than x_m_l_http_request.

What separators does it recognise?

Spaces, tabs, newlines, hyphens and underscores, plus case boundaries within a word. That means kebab-case, snake_case, camelCase and plain prose all convert to any other style without preparation.

Is converting to the same case a no-op?

Yes. Running already_snake_case through snake_case returns it unchanged, so it is safe to apply the converter to a mixed list where some entries are already correct.

Why does Sentence case lowercase my acronyms?

Because that is what sentence case means: one capital at the start and lowercase after. NASA launched the JWST becomes Nasa launched the jwst. If you need acronyms preserved, use Title Case or fix them by hand afterwards.

Does Title Case follow AP or Chicago style?

No. Every word is capitalised, including articles and short prepositions, so the lord of the rings becomes The Lord Of The Rings rather than the stylebook's The Lord of the Rings. Treat it as a mechanical transform, not an editorial one.

Does it work with accented and non-Latin text?

Yes. Word detection uses Unicode letter classes, so école normale supérieure title-cases to École Normale Supérieure. An earlier version capitalised the second letter of such words.

Which case should I use for a JSON API?

camelCase is the prevailing convention for JSON keys, because the largest consumers of JSON are JavaScript clients that use it natively. snake_case is common in APIs written in Python or Ruby, and either is fine as long as one is used consistently across every endpoint.

When should I use snake_case rather than kebab-case?

snake_case for identifiers in Python, Ruby, SQL and most database columns, where a hyphen would be read as subtraction. kebab-case for URLs, CSS class names and file names, where hyphens are conventional and, for URLs, better for search engines.

What is CONSTANT_CASE for?

Values that never change: environment variables, compile-time constants and enum members in most languages. It is snake_case in capitals, and the convention is old enough that a reader takes an all-caps identifier as a promise the value is fixed.

Can I convert a whole list at once?

Yes. Paste multiple lines and each is converted, which is the usual way to rename a column list or a set of keys in one pass.

Does the tool change punctuation?

Title Case and Sentence case preserve punctuation and spacing exactly. The programmer cases deliberately do not - they discard separators and rebuild the string, because an identifier cannot contain arbitrary punctuation.

Is my text uploaded anywhere?

No. Conversion runs in your browser, nothing is transmitted and nothing is logged, so pasting internal field names is safe.

Does it work offline?

Yes. Once the page has loaded the converter needs no network connection.

Why did my text with numbers convert oddly?

Digits are treated as part of the word they sit in, so a1b2 c3 becomes A1B2_C3 rather than splitting at each digit. A digit followed by a capital does count as a boundary, which is what you want for names like version2Handler.

Which case should I use for JSON keys?

camelCase is the prevailing convention, because the largest consumers of JSON are JavaScript clients that use it natively. snake_case is common in APIs written in Python or Ruby, and either is defensible as long as one is used consistently across every endpoint.

Case Converter

Convert text between different cases (uppercase, lowercase, camelCase, snake_case, etc.)

Enter text to convert

UPPERCASEHELLO WORLD

Result appears here

lowercasehello world

Result appears here

Title CaseHello World

Result appears here

Sentence caseHello world

Result appears here

camelCasehelloWorld

Result appears here

PascalCaseHelloWorld

Result appears here

snake_casehello_world

Result appears here

kebab-casehello-world

Result appears here

CONSTANT_CASEHELLO_WORLD

Result appears here

Category:text

Mode:Offline

Version:1.0.0

Access:Free

What is Case Converter?

Case Converter interface on Toolz.dev - Convert text between different cases (uppercase, lowercase, camelCase, snake_case, etc.)

Case Converter is a free online tool that instantly transforms text between different letter cases and naming conventions. Whether you need to convert a paragraph to uppercase, format a variable name in camelCase, or transform headings into title case, this tool handles it all with a single click.

The tool supports a wide range of case formats including uppercase, lowercase, title case, sentence case, camelCase, PascalCase, snake_case, kebab-case, and more. It is especially useful for developers who need to switch between programming naming conventions, writers formatting headings, or anyone working with text that needs consistent casing.

All text processing happens directly in your browser, so your content never leaves your device. Simply paste your text, select your desired case format, and copy the transformed result. It works with any language and any length of text, making it a versatile addition to your productivity toolkit.

The programmer cases are where conversions disagree, and it helps to know what to expect. Acronyms are the classic problem: HTTPServer can reasonably become httpServer or hTTPServer depending on whether the converter treats a run of capitals as one word, and codebases genuinely differ on which they prefer. Separators matter too, since converting to camelCase has to decide what counts as a word boundary in a string mixing spaces, hyphens, underscores and digits. There is also a locale trap worth knowing about even though it rarely bites in the browser: in Turkish, the uppercase of i is a dotted capital and the lowercase of I is a dotless one, which is why case conversion in server code is a documented source of bugs when the machine locale is not what the developer assumed. Conversions here use invariant rules.

How to use Case Converter?

Enter your text

Paste or type the text you want to convert into the input field. The tool accepts any amount of text, from a single word to entire documents.

Choose a case format

Select from available case options: uppercase, lowercase, title case, sentence case, camelCase, PascalCase, snake_case, kebab-case, and more.

View the result

The converted text appears instantly in the output area. You can see the transformation in real-time as you type or change case options.

Copy the output

Click the copy button to copy the converted text to your clipboard. Paste it anywhere you need the formatted text.

Key Features

Detects Word Boundaries

Splits on spaces, hyphens, underscores and existing camel humps, so XMLHttpRequest and my-variable-name both convert cleanly

Multiple Case Formats

Supports uppercase, lowercase, title case, sentence case, camelCase, PascalCase, snake_case, kebab-case, and more

Instant Conversion

Text is converted in real-time as you type or paste, with no delays or loading screens

Developer-Friendly

Quickly switch between programming naming conventions like camelCase, snake_case, and PascalCase

Frequently Asked Questions

The tool supports uppercase, lowercase, title case, sentence case, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, and dot.case. Each format is useful for different contexts like writing, coding, and data formatting.

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Case Converter

What is Case Converter?

How to use Case Converter?

Enter your text

Choose a case format

View the result

Copy the output

Key Features

Detects Word Boundaries

Multiple Case Formats

Instant Conversion

Developer-Friendly

Frequently Asked Questions

Related Tools

Line Sorter

String Reverse

Text Diff Checker

Word Frequency Counter

Comments

Case Converter

What is Case Converter?

How to use Case Converter?

Enter your text

Choose a case format

View the result

Copy the output

Key Features

Detects Word Boundaries

Multiple Case Formats

Instant Conversion

Developer-Friendly

Frequently Asked Questions

Related Tools

Line Sorter

String Reverse

Text Diff Checker

Word Frequency Counter

Comments