Case Converter
Instantly convert text to lowercase, UPPERCASE, camelCase, snake_case, PascalCase, Title Case, and 7 more naming formats online.
Input Text
Enter the text to format
Result
The formatted output text
About Case Converter
A case converter is a free online tool that instantly transforms any text into the letter-case format you need — no coding required. ToolMono's Case Converter supports 13 different formats: camelCase, PascalCase, snake_case, CONSTANT_CASE, kebab-case, dot.case, path/case, Header-Case, UPPERCASE, lowercase, Sentence case, and Capital Case. To check lengths, copy it to our Word Counter, or test formats using the Lorem Ipsum Generator to preview layouts.
Developers reach for a lowercase or uppercase converter daily: mapping database column names to JSON properties, renaming variables to match a project's style guide, or preparing identifiers before a code review. Writers and editors rely on the Title Case converter and Sentence case converter to format article headlines according to AP Style, the Chicago Manual of Style, or APA guidelines. Students and professionals use the capitalization converter to quickly clean up pasted text that arrived in the wrong case.
Unlike writing a one-off script in Python, JavaScript, or Bash, this browser-based case converter is instant — paste your text, pick a format, and copy the result in under three seconds. There is no installation, no account, and no rate limit. Major naming conventions are well-defined: camelCase is the default for JavaScript variables per the ECMAScript specification, PascalCase is standard for class names and React components, snake_case is the norm in Python per PEP 8, and SCREAMING_SNAKE_CASE is reserved for compile-time constants. A reliable free online case converter saves hours of tedious manual editing during refactors, API integrations, and content production workflows.
How to Use
Real-World Examples
Refactoring Database Columns to JSON Properties
When building a REST API, your database columns are typically in snake_case (e.g., user_first_name, order_created_at), but JavaScript and JSON conventions use camelCase. Paste your column list and select camelCase to instantly produce userFirstName and orderCreatedAt — no manual editing required.
user_first_name order_created_at product_sku_code
userFirstName orderCreatedAt productSkuCode
Formatting Article Headlines with Title Case
Editorial teams and content marketers routinely need to convert draft titles — which arrive in all-lowercase or sentence case — into properly formatted Title Case for publication. Paste the title and select 'Title Case' for AP-style output in one click.
why open source software matters for the modern developer
Why Open Source Software Matters for the Modern Developer
Converting Python snake_case to JavaScript camelCase
When integrating a Python API into a JavaScript frontend, method names need to be translated from Python's snake_case convention (PEP 8) to JavaScript's camelCase convention (ECMAScript). Paste the Python function names, select camelCase, and the conversion is done instantly.
get_user_profile update_order_status calculate_total_price
getUserProfile updateOrderStatus calculateTotalPrice
Fixing an Accidental All-Caps Block of Text
If you accidentally typed with Caps Lock on, or received text in ALL CAPS that needs to be readable, use the 'Sentence case' format to restore normal capitalisation instantly — first letter uppercase, the rest lowercase.
PLEASE READ THIS CAREFULLY BEFORE SUBMITTING YOUR FORM.
Please read this carefully before submitting your form.
Best Practices
- Use PascalCase for class names, React components, TypeScript interfaces, and constructor functions. Every major OOP language — Java, C#, TypeScript, and Kotlin — uses PascalCase for types and classes.
- Use camelCase for variables, object properties, and standard functions in JavaScript and TypeScript, as specified by the ECMAScript style conventions and enforced by tools like ESLint and Prettier.
- Use SCREAMING_SNAKE_CASE (CONSTANT_CASE) for module-level constants and environment variables across all languages, making immutable values visually distinct from mutable variables at a glance.
- Use kebab-case for CSS class names, HTML element IDs, and URL slugs. Kebab-case is human-readable in URLs and is the default output of CSS methodologies like BEM and utility frameworks.
- Use snake_case for Python identifiers — variables, functions, methods, and module names — as recommended by Python Enhancement Proposal (PEP 8), the official Python style guide.
- When writing article titles or document headings, follow the style guide relevant to your publication: AP Stylebook or Chicago Manual of Style for journalism and non-fiction, APA for academic writing. All three recommend Title Case for major headings with prepositions and conjunctions in lowercase.
Common Errors
Using kebab-case for JavaScript variable names
Hyphens are subtraction operators in JavaScript, so 'my-variable' is parsed as 'my minus variable', causing a SyntaxError. Use camelCase ('myVariable') for JS/TS identifiers. Reserve kebab-case exclusively for CSS class names, HTML IDs, and URL paths.
Confusing PascalCase with camelCase in code reviews
The only difference is the first letter: camelCase starts lowercase ('myFunction'), PascalCase starts uppercase ('MyFunction'). A quick rule: if it's a value you call or assign (function, variable), use camelCase. If it's a type you instantiate or extend (class, component, interface), use PascalCase.
Applying Title Case to every word including articles and prepositions
According to the AP Stylebook and Chicago Manual of Style, words like 'a', 'an', 'the', 'in', 'of', 'and', 'but', and 'or' should remain lowercase in a title unless they are the first or last word. Use the AP Style Title Case converter option for correct output.
Pro Tips
For bulk renaming, paste a newline-separated list of identifiers rather than converting one at a time. The converter handles multi-line input and converts each line independently, making it ideal for migrating entire lists of API field names or CSS classes.
If you are converting for a CSS-in-JS or Styled Components project, use the camelCase format for property names (backgroundColor) and the PascalCase format for component names (StyledButton) in the same session — just re-select the format between conversions.
When proofreading blog posts or articles, use the Word Counter tool to check your character count after reformatting headings — keeping page titles under 60 characters is critical for search engine display.
When generating placeholder variable names for testing, use ToolMono's Lorem Ipsum Generator to create sample text, then run it through the Case Converter to produce realistic-looking identifier names in any convention.
Frequently Asked Questions
What is a case converter?
A case converter is an online tool that instantly transforms text from one letter-case style to another — such as from lowercase to UPPERCASE, camelCase, snake_case, PascalCase, or Title Case. ToolMono's Case Converter supports 13 formats, eliminating the need to write conversion scripts or manually retype text when naming conventions change.
What is the difference between camelCase and PascalCase?
camelCase starts with a lowercase letter and capitalises each subsequent word (e.g., 'userFirstName'). PascalCase (also called UpperCamelCase) capitalises every word including the first (e.g., 'UserFirstName'). In JavaScript, camelCase is standard for variables and functions; PascalCase is used for class names and React component names per community style guides.
When should I use snake_case vs. kebab-case?
Use snake_case (underscores between words, e.g., 'max_retry_count') for Python variables, functions, and module names as recommended by Python PEP 8. Use kebab-case (hyphens between words, e.g., 'max-retry-count') for CSS class names, HTML IDs, and URL slugs. Kebab-case cannot be used for JavaScript identifiers because hyphens are parsed as subtraction operators.
How do I convert text case in Python?
Python has built-in string methods: str.lower() for lowercase, str.upper() for UPPERCASE, str.title() for Title Case, and str.capitalize() to capitalise only the first character. For camelCase or snake_case conversions, install the 'inflection' package or use ToolMono's free online Case Converter for a fast, no-code solution that requires no environment setup.
How do I change text case in Microsoft Word or Google Docs?
In Microsoft Word, select your text and press Shift+F3 to cycle through UPPERCASE, lowercase, and Sentence case. In Google Docs, go to Format > Text > Capitalization to choose your preferred style. Neither application supports camelCase, snake_case, or PascalCase natively — use ToolMono's Case Converter for those developer-focused formats.
How do I convert case in Excel?
Excel has three built-in worksheet functions: =LOWER(A1) produces lowercase, =UPPER(A1) produces UPPERCASE, and =PROPER(A1) produces Title Case. For developer naming conventions like camelCase or snake_case, which Excel does not support natively, paste the cell value into ToolMono's Case Converter, convert it, and paste the result back into your spreadsheet.
What is Title Case and when should I use it?
Title Case capitalises the first letter of major words in a phrase (e.g., 'The Quick Brown Fox Jumps'). Use it for article headlines, book titles, presentation headings, and product names. The AP Stylebook and Chicago Manual of Style both recommend keeping articles, coordinating conjunctions, and short prepositions lowercase unless they are the first word in the title.
What is SCREAMING_SNAKE_CASE (CONSTANT_CASE)?
SCREAMING_SNAKE_CASE (also called CONSTANT_CASE) uses all uppercase letters with underscores separating words (e.g., MAX_RETRY_COUNT). It is the universal convention for compile-time constants in JavaScript, Python, Java, and C++. The strong visual contrast clearly distinguishes immutable constant values from mutable variables in source code, improving readability during code review.
Is this Case Converter tool free to use?
Yes. ToolMono's Case Converter is 100% free with no usage limits, no account required, and no subscriptions. All 13 case formats — camelCase, PascalCase, snake_case, UPPERCASE, lowercase, Title Case, Sentence case, Header-Case, CONSTANT_CASE, dot.case, kebab-case, path/case, and no case — are available instantly without paying or signing up.
Is my text data safe and private when using this tool?
Yes. All conversion runs entirely inside your browser using client-side JavaScript. Your text is never transmitted to ToolMono's servers, never stored in a database, and never logged anywhere. You can safely paste proprietary source code, confidential business documents, API secrets, or sensitive personal data without any privacy or security concern.
Keyboard Shortcuts
| Shortcut | Action |
|---|---|
CtrlC | Copy the converted output from the Result panel |
CtrlV | Paste text into the Input area |
Security & Privacy
All text conversion in ToolMono's Case Converter runs entirely inside your browser using client-side JavaScript. Your text is never transmitted to ToolMono's servers, never stored in a database, and never logged anywhere. This means you can safely paste proprietary source code, API keys, confidential business data, or sensitive documents without any privacy or security risk. The tool works fully offline once the page has loaded.