Case Converter

Sentence case is how you normally write: the first letter of each sentence is a capital and the rest is lower case. This converter lower-cases the text and then capitalizes the first letter of the text, of every new line or paragraph, and of every sentence that follows a full stop, question mark, exclamation mark or ellipsis.

It's a rule of thumb, not grammar. It can't know that "london" or "q3 labs" should keep their own capitalization, and it will treat the text after an abbreviation like "e.g." as a new sentence, so give the result a quick read.

Capitalized Case is simpler than title case: the first letter of every word is a capital and the rest is lower case, with no exceptions for small words. It suits names, labels and menu items. Compare "The Lord of the Rings" (title case) with "The Lord Of The Rings" (capitalized case).

Before joining, the converter breaks each line into words. It treats these as word boundaries:

• spaces, tabs, hyphens, underscores, periods, slashes and other punctuation;
• camelCase and PascalCase humps, so helloWorld becomes hello + World;
• acronyms followed by a word, so XMLParser becomes XML + Parser.

Letters and digits stay together (Q3 is one word), numbers are always kept, and apostrophes inside words are dropped (don't becomes dont). Emoji and symbols act as separators and are removed. This is a practical rule-based approach and not a linguistic analysis, so unusual names such as "O'Neil" may split in surprising ways.

For programming, case is part of the syntax and the culture of a language: JavaScript favours camelCase for variables and PascalCase for components, Python favours snake_case, CSS and URLs favour kebab-case, and constants are usually CONSTANT_CASE. Following a project's convention keeps code readable. If you're building software, our web development team works with these conventions every day.

For writing, case is about readability and tone. Consistent capitalization in headings, buttons and lists makes content look professional, and it matters for content marketing and SEO copy where headlines are the first thing people read.

The converter uses JavaScript's standard Unicode case mapping, so accented Latin letters, Greek and Cyrillic convert as you would expect, and characters without case (Chinese, Japanese, Korean, emoji) are left untouched. Combining accents stay attached to their letters.

That is basic character-level case conversion, not language-aware editorial capitalization. It doesn't know that German nouns are capitalized, that Turkish has a dotted and a dotless i, or how titles are capitalized in French or Spanish. For those, use the result as a starting point and edit it yourself.