Case Converter Free Online
Convert text between UPPERCASE, lowercase, Title Case, Sentence case, camelCase, PascalCase, snake_case, kebab-case, and more. One click, instant results. Handles multi-line text, Unicode letters, and mixed input. Runs entirely in your browser.
Input
Output
Pro — bulk file conversion, custom delimiter rules, API access, batch processing
API access · Priority queue · Team workspace
How It Works
Paste Your Text
Paste any text into the input panel — a single word, a sentence, a paragraph, a block of code identifiers, or multi-line content. The converter handles text of any length and any mix of cases. Click Sample to load a realistic example showing a mixed-case paragraph that will be transformed by each case option, giving you a clear preview of how each format changes the text structure.
Click a Case Button
Click any of the 12 case format buttons. The output updates instantly — no submit needed. The active button highlights in orange to show which format is currently applied. You can click through all formats rapidly to find the one you need. The output panel shows the converted text and the stats bar displays word, character, and line counts so you can verify the transformation is correct.
Copy or Download
Copy the converted text to clipboard with one click, or download it as a plain text file. The input panel also updates live as you type — the last active case is reapplied automatically so you can edit your input and see the converted output update in real time. Switch between formats freely without losing your input text.
Case Converter Features
12 case formats including programming naming conventions and typographic styles
Programming Case Formats
Four naming conventions used in code: camelCase (JavaScript variables, Java methods), PascalCase (class names, TypeScript interfaces, React components), snake_case (Python variables, database columns, Ruby), and kebab-case (CSS classes, HTML attributes, URL slugs). All four correctly split words on spaces, existing case boundaries, numbers, and underscores/hyphens.
Typographic Case Formats
Title Case capitalizes the first letter of every word — used for headings, book titles, and article headlines. Sentence case capitalizes only the first letter of the first word in each sentence — correct for body text and most everyday writing. Both correctly handle punctuation boundaries and reset capitalization after periods, question marks, and exclamation points.
Extended Formats
CONSTANT_CASE (SCREAMING_SNAKE_CASE) is the convention for constants in C, Java, and JavaScript (MAX_RETRY_COUNT). dot.case is used in configuration keys and some logging systems. aLtErNaTiNg CaSe alternates upper and lower each character. iNVERSE CASE flips the case of every character in the original input.
Smart Word Splitting
For programming formats (camelCase, snake_case, etc.), the tool splits words intelligently: on spaces and punctuation, on existing camelCase boundaries (uppercase letters following lowercase), on transitions between letters and numbers, and on existing underscores and hyphens. This means pasting an existing camelCase variable name like getUserFirstName and converting to snake_case produces get_user_first_name correctly.
Live Preview
The output updates instantly as you type in the input panel — there is no Convert button to click after the initial case selection. This makes the tool useful for real-time editing: type or paste your text, click the target case once, then continue editing and see the converted output follow along. This is especially useful when writing variable names or slug identifiers that need to match a specific naming convention.
100% Private
All text processing runs locally in your browser using JavaScript string methods. No text is ever transmitted to a server, logged, or stored anywhere. Safe for converting identifiers and variable names from proprietary codebases, confidential document titles, internal product names, and any other sensitive text content that must not be exposed to third-party tools or analytics services.
Free vs Pro
| Feature | Free | Pro |
|---|---|---|
| All 12 case formats | ||
| Live preview as you type | ||
| Bulk file conversion | — | |
| Custom word boundary rules | — | |
| REST API access | — | |
| Code identifier rename tool | — |
Frequently Asked Questions
camelCase starts with a lowercase letter and capitalizes the first letter of each subsequent word: getUserName. PascalCase (also called UpperCamelCase) capitalizes the first letter of every word, including the first: GetUserName. camelCase is standard for variable and function names in JavaScript, Java, Go, and Swift. PascalCase is used for class names, TypeScript interfaces, React component names, and C# methods.
Use snake_case for Python variable and function names, Ruby symbols, and database column names — these contexts allow underscores in identifiers. Use kebab-case for CSS class names, HTML data attributes, URL slugs, npm package names, and YAML configuration keys — these contexts use hyphens as the conventional separator. Note that kebab-case identifiers are not valid JavaScript or Python variable names because the hyphen is interpreted as the subtraction operator.
Title Case capitalizes the first letter of every word: "The Quick Brown Fox". Sentence case capitalizes only the first letter of the first word of each sentence: "The quick brown fox". Title Case is used for book titles, movie titles, article headlines, and UI headings. Sentence case is used for body text, email subjects, blog post titles in some style guides (AP, Chicago), and most UI labels. Sentence case is generally considered more modern and easier to read.
Yes — the tool's smart word splitter detects case boundaries in existing identifiers. Pasting getUserFirstName and clicking snake_case produces get_user_first_name. Pasting get_user_first_name and clicking camelCase produces getUserFirstName. You can convert freely between all programming naming conventions. For renaming identifiers across an entire codebase, the Pro version offers batch file processing.
CONSTANT_CASE (also called SCREAMING_SNAKE_CASE or UPPER_SNAKE_CASE) is the convention for named constants in many languages. In C and C++, preprocessor macros use this format (MAX_BUFFER_SIZE). In Java, static final constants follow this convention (DEFAULT_TIMEOUT_MS). In JavaScript and TypeScript, module-level constants and enum values often use it. The all-caps format visually distinguishes constants from variables at a glance in code reviews.
Yes — all text processing runs entirely in your browser. Nothing you type or paste is transmitted to any server. You can verify this by disconnecting from the internet and confirming the tool still converts text. This makes it safe to paste proprietary code identifiers, confidential document titles, internal product names, and personal content that must not be sent to external services.