A case converter for titles, sentences and code
Typed a heading with Caps Lock on? Need a list of product names in Title Case, or variable names in snake_case? The Case Converter changes the capitalisation of any text in one click: UPPER CASE, lower case, Title Case, Sentence case, Capitalize Each Word, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, dot.case, aLtErNaTiNg and iNVERSE.
This is not a simple “capitalise every word” tool. Title Case follows real style-guide rules — small words such as a, of and the stay lowercase unless they open or close the title — and you can switch between Chicago and AP/APA style. Acronyms and brand names like NASA, iPhone and eBay are kept as they are. Everything runs in your browser, so drafts and code never leave your device.
How to use the Case Converter
- Paste or type your text into “Your text”. Each line is converted on its own, so you can do a whole list at once.
- Click a button under “Convert to”, for example Title Case or snake_case. The result appears straight away below.
- For titles, choose the “Title Case style”: Chicago for books and blogs, AP / APA for news, essays and academic papers.
- Untick “Keep acronyms and brand names” if you want every word re-cased, including ones written in capitals.
- Press “Copy result”, download it as a .txt file, or use “Use result as input” to apply another conversion on top.
Case Converter features
13 cases, one click each
Every button converts immediately, and the result updates live as you edit the text.
Style-guide Title Case
Articles, short conjunctions and prepositions stay lowercase in the middle of a title; the first word, last word and the word after a colon are always capitalised.
Smart about acronyms
Mixed-case and all-caps words such as NASA, iPhone and McDonald are left alone — unless the whole line is in capitals, in which case it is treated as shouting and fixed.
Developer cases
camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE and dot.case split existing identifiers correctly, so XMLHttpRequest becomes xml_http_request.
Any language
Upper and lower case work for accented Latin, Greek and Cyrillic letters, including special cases such as German ß becoming SS.
Which case should you use?
| Case | Example | Typical use |
|---|---|---|
| UPPER CASE | ANNUAL REPORT 2025 | Short labels, warnings, acronyms |
| lower case | annual report 2025 | Tags, casual social posts, normalising data |
| Title Case | The Return of the King | Headlines, book and article titles, H1s |
| Sentence case | How to write a cover letter | Body text, UI labels, many modern headings |
| Capitalize Each Word | The Return Of The King | Names and labels where every word should start with a capital |
| camelCase / PascalCase | userName / UserName | JavaScript and Java variables / classes and components |
| snake_case / CONSTANT_CASE | user_name / MAX_RETRIES | Python and SQL names / constants and environment variables |
| kebab-case / dot.case | user-name / user.name | URLs, CSS classes, file names / config keys |
Title Case rules: Chicago vs AP and APA
All major style guides capitalise the first and last word of a title and every “major” word — nouns, verbs (including short ones like Is and Be), adjectives, adverbs and pronouns. They differ on the small words in between.
Chicago Manual of Style lowercases articles (a, an, the), the conjunctions and, but, for, or, nor, the words to and as, and every preposition regardless of length — so “A Guide to Working from Home with Kids”. AP and APA lowercase only short words of three letters or fewer and capitalise everything with four letters or more, giving “A Guide to Working From Home With Kids”.
Both styles capitalise the first word after a colon, which is how subtitles work: “Star Wars: A New Hope”. Hyphenated compounds are capitalised on each part, as in “Self-Driving Cars”, except for small words such as the of in “Out-of-Date”. For headings on a website, either style is fine — just use the same one everywhere.
Tips and edge cases
- Text in ALL CAPS: lines that are mostly capitals are converted fully, so “HOW TO WRITE A COVER LETTER” becomes “How to Write a Cover Letter”.
- Sentence case starts a new sentence after a full stop, question mark or exclamation mark and on each new line, and always writes the pronoun “I” in capitals.
- Words the tool cannot know: proper nouns such as “london” or “priya” cannot be detected automatically in Sentence case — check names after converting.
- For web addresses, use the Slug Generator, which also removes accents and punctuation. To change one word throughout a document rather than its case, use Find and Replace.
Case Converter FAQ
How do I convert text from uppercase to lowercase?
Paste the text and click “lower case”. To get normal capitalisation back instead, click “Sentence case”, which lowercases everything and then capitalises the first letter of each sentence.
Which words should not be capitalised in a title?
In most styles: articles (a, an, the), short coordinating conjunctions (and, but, or, nor, for) and short prepositions (at, by, in, of, on, to). Chicago style also lowercases longer prepositions such as “from”, “with” and “between”. The first and last words are always capitalised.
What is the difference between Title Case and Capitalize Each Word?
Title Case follows style-guide rules and keeps small words such as “of” and “the” lowercase. Capitalize Each Word simply gives every word a capital first letter, which suits names, labels and some product listings.
Will the case converter change my acronyms?
Not with “Keep acronyms and brand names” ticked: words with capitals after the first letter, like NASA or iPhone, are kept. If a whole line is in capitals it is treated as shouting and converted, because there is no way to tell acronyms apart in that case.
How does camelCase conversion handle existing names?
It splits words at spaces, hyphens, underscores, dots and existing capital letters, so “user_ID”, “user-id” and “UserId” all become “userId”. Apostrophes are dropped, so “don’t stop” becomes “dontStop”.
Is my text sent to a server?
No. The conversion runs in your browser with JavaScript, so nothing you paste is uploaded or stored.