Every Case Style, and When to Use It
Sentence case capitalizes only the first word and proper nouns — the default for body text, email, and most modern UX writing (Google's and Apple's interface guidelines both prefer it for buttons and labels). Title Case capitalizes principal words and is the convention for headlines, book titles, and section headings in American publishing. UPPERCASE carries emphasis and formality — legal disclaimers, warnings, acronyms — but reads as shouting in conversation and measurably slows reading in long passages. lowercase is a deliberate stylistic choice in branding and casual writing.
Developers get four more: camelCase (userName — JavaScript and Java variables), PascalCase (UserProfile — class and component names), snake_case (user_name — Python variables, database columns), and kebab-case (user-profile — URLs, CSS classes, file names). Converting identifiers between these when porting code or naming API fields is this tool's most common use.
The Title Case Trap
Title case is trickier than "capitalize every word". Publishing styles (AP, Chicago, MLA) agree that major words get capitals while short conjunctions, articles, and prepositions — a, an, the, and, but, or, of, in, on — stay lowercase unless they begin or end the title. So "the lord of the rings" becomes "The Lord of the Rings", not "The Lord Of The Rings". The lazy every-word version is one of the most common typographic mistakes in blog headlines and slide decks; a proper converter handles the exception words for you.
Typical Rescue Jobs
- The caps-lock accident: a paragraph typed WITH CAPS LOCK ON converts to sentence case in one click instead of being retyped.
- Imported data cleanup: customer names arriving as "JOHN SMITH" or "john smith" from legacy systems normalize to "John Smith" before a mail merge.
- Headline consistency: unifying a blog's mixed headline styles into proper title case across every post.
- Code refactoring: converting a batch of
snake_case API field names to camelCase for a JavaScript client, without introducing typos by hand.
- URL slugs: turning a post title into a clean kebab-case slug like
my-post-title for SEO-friendly URLs.
While cleaning up text you'll often want counts too — our Word Counter reports words, characters, and reading time for the same paste.
Frequently Asked Questions
Does the converter change anything besides letter case?
No — spacing, punctuation, numbers, and line breaks pass through untouched. Only the capitalization of letters changes (except in the developer cases, which also join or split words with underscores, hyphens, or capitals).
Will names like "McDonald" or "iPhone" survive sentence case?
Automatic converters can't reliably know which words are proper nouns or trademarks, so unusual internal capitals may be flattened. Convert first, then fix the handful of special names — still far faster than retyping.
Is my text stored or sent anywhere?
No — conversion is instant, local JavaScript. Paste confidential drafts freely; nothing leaves your browser.
What's the difference between camelCase and PascalCase?
Only the first letter: userName vs UserName. Most style guides use camelCase for variables and functions, PascalCase for classes, types, and React components — mixing them up is a common code review nitpick.
Is there a length limit?
Practically none — entire documents convert instantly, since the operation is a simple character-by-character pass.