Case Converter

Convert text between UPPERCASE, lowercase, Title Case, camelCase, snake_case and five more formats — all in one tool.

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Output

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What Is the Case Converter?

The Case Converter is a free online tool that instantly transforms text between ten different letter case formats. From writing clean code to formatting headlines for publication, case conversion is something writers, developers, SEO professionals, and content creators do dozens of times every day. This tool handles all the common formats in one place — no need to use multiple tools or write manual find-and-replace scripts.

Supported formats include UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, and dot.case. All processing happens locally in your browser, instantly, with no data sent anywhere.

Why Case Conversion Matters

Different contexts have firm conventions around letter case, and using the wrong format has real consequences. In programming, choosing the wrong case format can cause compile errors, break naming conventions enforced by linters, or create naming inconsistencies that slow down code review. In content writing and SEO, title case versus sentence case is often specified by a brand's style guide, and mixing them creates a sloppy, unprofessional impression. In data processing, inconsistent case in text fields causes silent mismatch errors in searches, joins, and comparisons.

A reliable, instant case conversion tool removes the mental overhead and error risk of manual conversion, especially for programming identifiers where a single incorrectly capitalized letter can break a build.

Understanding Each Case Format

UPPERCASE

Every letter is capitalized. Used for acronyms, programming constants, labels that require strong visual emphasis, and legal document headings. Example: THE QUICK BROWN FOX.

lowercase

Every letter is in its lower form. Used for email addresses, URLs, CSS class names in many conventions, code identifiers in Python and Ruby, and any context where consistent lowercase is required. Example: the quick brown fox.

Title Case

The first letter of each major word is capitalized. Used for book titles, movie titles, article headings, product names, and brand assets. The rules for which words to capitalize vary slightly between style guides (AP, Chicago, MLA), but the general principle is to capitalize all words except short prepositions, articles, and conjunctions. Example: The Quick Brown Fox Jumps Over the Lazy Dog.

Sentence case

Only the first letter of the first word is capitalized, exactly like the start of an English sentence. Used for most body text, UI button labels, form placeholders, and many modern blog post title conventions. Example: The quick brown fox.

camelCase

The first word is all lowercase, and each subsequent word begins with a capital letter, with no spaces or separators. This is the standard naming convention in JavaScript, Java, Swift, TypeScript, and many other languages for variable and function names. Example: theQuickBrownFox.

PascalCase

Like camelCase, but the first word also starts with a capital. Every word begins with an uppercase letter. Used for class names and type names in C#, Java, TypeScript, and most object-oriented languages. Also used for React component names. Example: TheQuickBrownFox.

snake_case

All lowercase, with words separated by underscores. The primary naming convention in Python for variables, functions, and modules; also used for SQL column names and database table names in most SQL dialects. Example: the_quick_brown_fox.

kebab-case

All lowercase, with words separated by hyphens. Used for CSS class names, HTML data attributes, URL slugs, file names in many JavaScript frameworks, and configuration keys in YAML and JSON. Example: the-quick-brown-fox.

CONSTANT_CASE

All uppercase with underscores as separators. Used universally for constants and environment variables in almost all programming languages. Example: THE_QUICK_BROWN_FOX.

dot.case

All lowercase with dots as word separators. Used in configuration files, Java package names, logging framework hierarchies, and some API endpoint conventions. Example: the.quick.brown.fox.

How to Convert Text Case

Type or paste your text into the input field. The original text is preserved and you can apply any case format at any time by clicking the corresponding button. The converted text appears immediately in the output field. Click Copy to send it to your clipboard. You can switch between different formats without re-entering your text — apply as many conversions as you need to find the right format.

Common Workflows

Developers converting API field names: An API returning user_first_name in snake_case needs to be referenced as userFirstName in JavaScript. Paste the field name, click camelCase, copy the result.

Content editors formatting headlines: A draft headline needs to match the brand's title case style guide. Paste the headline, click Title Case, review and copy.

Database administrators: Table column names from an export need to be converted to snake_case before use in a Python script. Paste the names, convert to snake_case, copy the result.

Frequently Asked Questions

What is the difference between camelCase and PascalCase?

In camelCase, the first word is entirely lowercase and subsequent words start with a capital letter (e.g., myVariableName). In PascalCase — also called UpperCamelCase — every word including the first one starts with a capital letter (e.g., MyVariableName). camelCase is typically used for function and variable names in JavaScript and Java, while PascalCase is used for class names, type names, and React component names.

Does the Title Case converter follow AP, Chicago, or MLA style?

This tool applies a general Title Case rule that capitalizes the first letter of every word. It does not implement the specific word-exception lists from any particular style guide (AP exempts words like "and," "the," "of"; Chicago has a similar but different list). For strict style guide compliance, treat this tool's output as a starting point and manually review minor words like prepositions, articles, and conjunctions.

Can I convert multiple lines of text at once?

Yes. You can paste as many lines or paragraphs as needed. The conversion applies to the entire text block, processing every word consistently regardless of the number of lines or paragraphs. For code-style conversions like snake_case and kebab-case, each line is treated as a separate identifier.

What happens to numbers and special characters during conversion?

Numbers are left unchanged — they do not have case. Most special characters and punctuation are also left as-is. In snake_case and kebab-case conversions, spaces are replaced with underscores or hyphens respectively, and non-alphanumeric characters that are not letters or numbers are generally removed. Hyphens and underscores already in the text are preserved where appropriate.

Is this tool useful for working with databases?

Extremely useful. Database column names almost universally use snake_case, but application-level code often uses camelCase or PascalCase. This tool makes it easy to convert between conventions when writing queries, generating code from schema definitions, or preparing field names for use in ORMs and data models.

Does the case converter work with non-English text?

Yes for European languages that use the Latin alphabet with accented characters (é, ñ, ü, ç, etc.) — the tool correctly uppercases and lowercases these. For non-Latin scripts (Arabic, Chinese, Japanese, Korean, Hebrew, Devanagari), case conversion does not apply because those writing systems do not have uppercase and lowercase distinctions. The text will pass through unchanged.

Is there a character or word limit?

No. The tool processes text of any length, all handled locally in your browser. There is no server-side limit. You can convert a single word or an entire document.