Case Converter
Paste text, pick a case, and the converted copy appears live — UPPERCASE, lowercase, Title Case, Sentence case, or aLtErNaTiNg. Everything runs in your browser; nothing is uploaded.
Three jobs: shouting fixes, titles, data cleanup
Most visits to a case converter are one of three rescues. The first is the caps-lock accident — a paragraph typed IN FULL SHOUT that nobody wants to retype; Sentence case rebuilds it into ordinary prose in one click, capitalizing the start of each sentence and lowercasing the rest. The second is headline work: Title Case turns a draft heading into "Hello World. It's Fine." — first letter of every word up, rest down — ready for a blog title, slide, or subject line. The third is data cleanup: names, emails, or product codes pasted from a spreadsheet in inconsistent case, flattened with lowercase or UPPERCASE so duplicates finally match. And aLtErNaTiNg case is there because people genuinely search for it — the mocking-meme text, labeled as exactly that.
The conventions, stated plainly
Run the sample "hello WORLD. it's fine." through each transform: UPPERCASE gives "HELLO WORLD. IT'S FINE.", Title Case gives "Hello World. It's Fine.", and Sentence case gives "Hello world. It's fine.". Two positions worth knowing. Title Case here is the simple convention — every word's first letter is capitalized, with no editorial minor-word rules, so "of" and "the" get capitals that AP or Chicago style would lowercase mid-title; if you write to a house style, treat the output as a starting point. Sentence case capitalizes after sentence-ending punctuation, which means a period after an abbreviation triggers a capital that a human editor would not add — the same stated limitation as our sentence counter. Case mappings use the default Unicode rules, so accented letters convert correctly (café → CAFÉ) but Turkish's dotless ı is not special-cased. The exact rules, with the word-token definition Title Case borrows from the word counter, are on the methodology page.
Frequently asked questions
What does Title Case capitalize?
The first letter of every word, with the rest of the word lowercased — the simple convention, applied to every word alike. Editorial styles like AP or Chicago additionally lowercase minor words ("of", "the", "and") mid-title; this tool deliberately does not, because those style rules disagree with each other and a predictable rule beats a partially-applied one. Apostrophes and hyphens stay inside a word, so "it's" becomes "It's" and "state-of-the-art" gets exactly one capital. A word that starts with a digit is left lowercase — "3rd edition" becomes "3rd Edition", not "3Rd Edition".
Why did Sentence case capitalize a word after an abbreviation?
Sentence case capitalizes after a period, exclamation point, question mark, or ellipsis followed by a space. A period after an abbreviation looks identical to a sentence end, so "dr. smith" becomes "Dr. Smith" with an extra capital on "Smith". This is the same documented abbreviation limitation as our sentence counter — stated plainly rather than hidden.
Does the converter handle accented and non-English letters?
Yes — café uppercases to CAFÉ, and Greek or Cyrillic letters convert with their standard Unicode mappings. One honest caveat: the tool uses the default (English) Unicode case rules, not locale-specific ones. Turkish distinguishes dotless ı/I from dotted i/İ, and under Turkish rules "i" would uppercase to "İ"; here it always becomes "I".
What is aLtErNaTiNg case for?
The mocking-text meme, mostly — it is genuinely one of the most-searched case transformations. Letters alternate lowercase and UPPERCASE starting lowercase, and spaces or punctuation pass through without breaking the alternation, so "a b!c" becomes "a B!c".
Is my text uploaded anywhere?
No. The conversion is plain JavaScript running locally on a static page — your browser makes zero network requests while you type, and a loaded page keeps converting offline.
Conversion happens locally in your browser — nothing you type is transmitted or stored. Counting the result instead? The word counter and letter counter handle lengths, and the sentence counter checks the rhythm of what you just recased.