Case Converter: Title Case, Sentence Case & More

The cases and when to use them

UPPERCASE: every letter capitalized. Good for short labels, acronyms, and warnings. Bad for paragraphs; all-caps text is slower to read and reads as shouting in email and chat.

lowercase: every letter small. Useful for normalizing data before comparing it, such as email addresses, tags, and usernames.

Title Case: major words capitalized, short articles, conjunctions, and prepositions lowercase. Used for headlines, book titles, and navigation labels. If you want literally every word capitalized, use Capitalize Each Word instead.

Sentence case: only the first letter of each sentence capitalized. Most modern interfaces, including Google, Apple, and Microsoft style guides, now prefer sentence case for buttons and headings because it is easier to scan.

kebab-case: lowercase words joined by hyphens with punctuation removed, ready for URLs. "10 Best Coffee Shops in Austin!" becomes 10-best-coffee-shops-in-austin.

Title case style guides

Real style guides do not capitalize every word. AP style lowercases articles (a, an, the), coordinating conjunctions (and, but, or), and prepositions of three letters or fewer, unless they start or end the title. Chicago style lowercases all prepositions regardless of length. APA capitalizes words of four letters or more.

Example: "a guide to the best hikes in the world" in AP style is "A Guide to the Best Hikes in the World". That is exactly what the Title Case button here produces: it follows AP, lowercasing a, an, the, and, but, or, for, nor, and short prepositions such as to, of, in, on, at, and by, while always capitalizing the first and last word and the word after a colon. A naive capitalize-every-word converter gives "A Guide To The Best Hikes In The World" instead, and many also break contractions into "Don'T". This one keeps "Don't" and capitalizes both halves of hyphenated words like "Well-Known". Chicago and APA differ on longer prepositions such as "with" and "about", so adjust those by hand if your publication follows them.

Fixing text typed with caps lock

Paste the text, convert to sentence case, then fix proper nouns. "I MET SARAH IN NEW YORK LAST MAY." becomes "I met sarah in new york last may." You still need to restore Sarah, New York, and May. No automatic converter can reliably know which words are names, so budget a quick proofread.

Cases for code

Programmers use a few more: camelCase for JavaScript variables, PascalCase for classes and React components, snake_case for Python variables and database columns, SCREAMING_SNAKE_CASE for constants, and kebab-case for CSS classes and URLs. The camelCase, snake_case, and kebab-case buttons split on spaces, punctuation, and existing camel humps, so "myVariableName" converts cleanly to my_variable_name.

Consistency matters more than the choice

The best case style is the one you use everywhere. A website that mixes Title Case and sentence case in its navigation looks unfinished, even if each label is correct on its own. Pick one style for headings, one for buttons, and one for navigation, write it down, and run new copy through the converter before it ships.

Brand names are the exception: iPhone, eBay, YouTube, and LinkedIn keep their own capitalization regardless of your style. So do acronyms like NASA and product codes. After converting, search your text for brand names and restore them.

Cleaning data with case conversion

Case mismatches cause quiet data problems. Spreadsheet lookups, email lists, and CRM imports often treat "[email protected]" and "[email protected]" as different records even though email domains are case-insensitive. Converting a column to lowercase before deduplicating can merge dozens of duplicate contacts.

The same applies to tags and categories. "Marketing", "marketing", and "MARKETING" should be one tag. Normalize to lowercase for storage and apply display case in the interface.

SEO and accessibility notes

Google treats uppercase and lowercase letters in URLs as different paths, so /Blog/Post and /blog/post can become duplicate pages. Keep URLs lowercase, which is exactly what slug case produces. Google ignores case in search queries, so capitalization in titles is purely about readability and click-through.

Screen readers may spell out words written in all caps letter by letter. If you want the visual effect, apply uppercase with CSS text-transform instead of typing it. Your text stays in the browser; nothing is uploaded.