Convert text between 11 capitalisation styles instantly — UPPERCASE, Title Case, camelCase, snake_case and more. Free, no sign-up, runs in your browser.
A case converter is an online tool that changes the capitalisation pattern of text. Instead of retyping content or editing it manually — which is slow and introduces errors — a case converter applies the transformation automatically and consistently across every word. The SmartWriteTools case converter supports eleven conversion modes covering everything from basic capitalisation changes to programming naming conventions.
Each capitalisation style has a specific use case. Understanding when to use each one helps you produce professional output across different contexts.
UPPERCASE capitalises every letter. Used for emphasis in design, acronyms like NASA or HTML, and programming constants like MAX_RETRY_COUNT. Use sparingly in running text — all caps is harder to read and can feel like shouting in digital communication.
lowercase sets every letter to its lowercase form. Used in URL slugs, hashtags, and informal digital contexts. It is also the starting point for most programming case conventions since machines are case-sensitive.
Title Case capitalises the first letter of major words. Minor words — articles (a, an, the), coordinating conjunctions (and, but, or), and short prepositions (in, on, at, by, to) — stay lowercase unless they appear as the first word. This is the standard format for book titles, article headings, film titles, and product names. Getting Title Case right manually is surprisingly error-prone, which is why a case converter tool is useful even for experienced writers.
Sentence case capitalises only the first letter of each sentence. This is the standard format for body text in English — the case you use in normal paragraphs.
camelCase removes spaces and capitalises the first letter of every word except the first: firstName, getUserEmail, isLoggedIn. This is the standard naming convention for variables and functions in JavaScript, Java, and Swift.
PascalCase is like camelCase but capitalises the first word too: UserProfile, HttpRequestHandler. Used for class names in most object-oriented languages including Python, Java, C#, and React component names.
snake_case joins words with underscores, all lowercase. Standard in Python variables and functions, Ruby, and database column names. kebab-case uses hyphens instead — common in CSS class names, HTML attributes, and URL slugs. CONSTANT_CASE is all-caps with underscores, used for named constants in most programming languages.
tOGGLE cASE inverts the case of every letter — useful for undoing an accidental Caps Lock. AlTeRnAtInG cAsE alternates between uppercase and lowercase letters, used as a stylistic device in informal digital communication.
Headings and titles → Title Case · Body text → Sentence case · JavaScript variables → camelCase · Class names → PascalCase · Python and databases → snake_case · CSS classes and URL slugs → kebab-case · Named constants → CONSTANT_CASE · Design emphasis → UPPERCASE (sparingly)
The most frequent error with Title Case is capitalising minor words that should stay lowercase. "The Lord Of The Rings" is wrong — "of" and "The" (when not the first word) should be lowercase. The case converter handles these rules automatically.
In programming, mixing conventions within a project causes readability problems and bugs. If your codebase uses camelCase for variables, a single snake_case variable stands out and can confuse other developers. A case converter helps maintain consistency when refactoring code or converting between conventions.
Another common issue is converting text that contains proper nouns. When you convert "The United Nations met in Geneva" to lowercase, it becomes "the united nations met in geneva" — losing the capitalisation that signals proper nouns. After converting, always review the output for proper nouns that need manual correction.
The tool runs entirely in your browser. Your text is never sent to any server, making it safe for confidential content, code, and business documents.
Can the case converter handle proper nouns correctly? No automatic tool can guarantee correct proper noun handling because case conversion operates on pattern rules, not semantic understanding. When you convert to lowercase or UPPERCASE, proper nouns like "England" or "Google" lose their capitalisation. After conversion, always review the output for proper nouns that need manual correction. The Title Case mode preserves capitalisation of the first and last words but does not know which words are proper nouns.
What is the difference between camelCase and PascalCase? Both join words without spaces and capitalise internal words. The difference is the first word: camelCase starts with a lowercase letter (getUserEmail, isLoggedIn), while PascalCase capitalises every word including the first (UserProfile, HttpRequestHandler). In programming, camelCase is standard for JavaScript variables and functions, while PascalCase is used for class names and React components. Mixing the two conventions in the same codebase causes readability problems.
Why should I use Title Case for headings? Title Case is the standard capitalisation style for English-language titles, headings, article names, and book titles. It signals a formal heading rather than a sentence, helping readers scan content structure quickly. Most style guides — including APA, MLA, Chicago, and AP — use Title Case for headings, though with minor differences in which words are capitalised. The converter follows standard Title Case rules, keeping minor words (a, an, the, and, but, or, in, on, at, by, to) lowercase unless they appear as the first or last word.
Is my text sent to a server when I use the case converter? No. The SmartWriteTools case converter runs entirely in your browser using JavaScript. Your text never leaves your device. This makes it safe for confidential content, proprietary code, and business documents.
For a detailed walkthrough with more examples, see our guide Case Converter Online.