About the Case Converter
This case converter rewrites any text in the letter case you need — UPPERCASE, lowercase, Title Case for headlines, Sentence case for body copy, Capitalized Each Word, aLtErNaTiNg and iNVERSE case — plus programmer formats such as camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE and dot.case. Paste the text, pick a style and copy the result.
It saves retyping when a paragraph was written with Caps Lock on, when a headline needs proper title capitalisation, or when you need to turn a phrase like "monthly payment amount" into a variable name such as monthlyPaymentAmount. The most common styles are shown side by side so you can copy whichever one fits.
Title Case follows common headline style: the first and last words and all major words are capitalised, while short articles, conjunctions and prepositions (a, an, the, and, of, to, in…) stay lowercase. Acronyms such as USA or 401K and mixed-case names such as iPhone are left untouched. Programmer cases split words at spaces, punctuation and existing camelCase boundaries and work line by line.
How to use the case converter
- 1Paste or type your text into the box.
- 2Choose the case you want from the list.
- 3Copy the converted text — or grab one of the other common styles shown below it.
Formula and method
UPPERCASE and lowercase use Unicode case mapping, so accented and non-Latin letters (é → É, ß → SS) convert correctly. The other styles only change a letter when it has a single-letter uppercase form, so a German ß is kept as ß rather than expanded to "SS". Sentence case lowercases everything, then capitalises the first letter of the text and the first letter after each full stop, question mark or exclamation mark that is followed by a space (so "example.com" is left alone), and restores the pronoun "I". Common mid-sentence abbreviations (i.e., e.g., vs., cf., approx., Mr., Mrs., Ms., Dr., St., fig.) are not treated as sentence ends. Abbreviations that often end a sentence (etc., a.m., p.m.) and all proper nouns cannot be told apart automatically, so check them by hand. Title Case capitalises every word except short minor words, which are only capitalised when they are the first or last word or follow a colon.
Programmer cases first split the text into words at spaces, punctuation and lower-to-upper boundaries (so "monthlyPayment" and "monthly payment" give the same words), remove apostrophes, then join the words: camelCase lowercases the first word and capitalises the rest, PascalCase capitalises all, and snake, kebab, CONSTANT and dot cases join with _, -, _ (upper) and . respectively.
Worked examples
Blog headline in Title Case
Major words are capitalised while "to", "an" and "in" stay lowercase because they are minor words in the middle of the title. The snake_case version joins the lowercase words with underscores.
Fixing a Caps Lock paragraph
Everything is lowercased, then the first letter of each sentence is capitalised after ".", "?" and "!". The pronoun "I" is restored to a capital.
Sentence case with an abbreviation
The full stop after "i.e." is followed by a space but is recognised as part of an abbreviation, so "spend" stays lowercase. The real sentence end after "less." capitalises "Start".
Turning a label into a variable name
The words monthly, payment, amount and USD are extracted, lowercased and joined with the first word in lowercase and the rest capitalised, giving monthlyPaymentAmountUsd. The kebab-case version is monthly-payment-amount-usd.
Frequently asked questions
What is the difference between Title Case and Sentence case?+
Title Case capitalises the main words of a heading ("How to Save Money Fast"), while Sentence case only capitalises the first word and proper nouns ("How to save money fast"). Many style guides now prefer sentence case for web headings.
Which words should not be capitalised in a title?+
Most headline styles keep articles (a, an, the), coordinating conjunctions (and, but, or, nor) and short prepositions (in, on, at, to, of, by) lowercase unless they start or end the title. AP, APA and Chicago differ slightly on longer prepositions.
How do I change uppercase to lowercase in Word or Google Docs?+
In Word, select the text and press Shift+F3 to cycle through cases. In Google Docs use Format → Text → Capitalization. For other apps, paste the text here, convert it and paste it back.
What is camelCase vs snake_case?+
camelCase joins words with no spaces and capitalises each word after the first (totalAmount), common in JavaScript and Java. snake_case joins lowercase words with underscores (total_amount), common in Python and databases.
Does the converter handle accented letters?+
Yes. Case changes use Unicode rules, so letters like é, ñ, ü, and Greek or Cyrillic letters convert correctly. The German ß becomes "SS" in UPPERCASE, which is the standard mapping; in Title, inverse and alternating case it stays ß.