Which case to use when
- Sentence case capitalises the first letter of each sentence and the word “I”. Use it for normal writing, email subject lines, button labels and most website headings, because it is the easiest to read.
- Title Case capitalises the main words and keeps short words such as a, an, the, and, of, in, to in lower case, unless they come first or last. Use it for book, film and article titles.
- Capitalized Case capitalises every word, including the short ones. It suits names, place lists and some product labels.
- UPPER CASE works for short labels, codes and warnings. Long passages in capitals are hard to read and can feel like shouting.
- lower case is useful for usernames, tags, email addresses and file names.
- aLtErNaTiNg cAsE and InVeRsE CaSe are mostly for fun, although inverse case also flips text that was typed with Caps Lock on by mistake.
How the title case rules work
This tool follows the common style used by most publishers: articles (a, an, the), short conjunctions (and, but, or, nor, so, yet) and short prepositions (at, by, for, in, of, off, on, per, to, up, via) stay in lower case in the middle of a title. The first and last words are always capitalised, and so is the first word after a colon. That is why “the return of the king” becomes “The Return of the King”.
Style guides differ on details such as longer prepositions (about, between, through), which this tool capitalises. If your teacher, journal or publisher has its own rules, give the result a quick check.
Things to watch for
Sentence case, Title Case and Capitalized Case lower the rest of each word before capitalising it. That fixes text like “hELLO”, but it also turns acronyms and brand names such as NASA, PDF or iPhone into “Nasa”, “Pdf” and “Iphone”. Scan the result for these and correct them by hand.
Letters with accents, such as é or ü, convert correctly. Scripts without capital letters, such as Urdu, Hindi and Arabic, are left exactly as they are, so mixed English and Urdu text is safe to convert.
Private by design
The conversion runs in your browser. Nothing you type is uploaded or stored, so it is safe for emails, assignments and documents you would rather keep to yourself.