The 12 cases at a glance
Paste once and every version appears together, so you can compare them before you copy. Here is the same phrase in each case, with where you would normally use it:
| Case | Example | Typical use |
|---|---|---|
| UPPERCASE | HOW TO TAKE BETTER PHOTOS | Short labels and warnings |
| lowercase | how to take better photos | Tags, usernames, email addresses |
| Title Case | How to Take Better Photos | Headlines, book and film titles |
| Sentence case | How to take better photos | Web headings, buttons, email subjects |
| camelCase | howToTakeBetterPhotos | JavaScript variables, JSON keys |
| PascalCase | HowToTakeBetterPhotos | Class and component names |
| snake_case | how_to_take_better_photos | Python, database columns |
| kebab-case | how-to-take-better-photos | URLs, CSS classes, file names |
| CONSTANT_CASE | HOW_TO_TAKE_BETTER_PHOTOS | Constants, environment variables |
| dot.case | how.to.take.better.photos | Config keys, some file names |
| aLtErNaTiNg | hOw To TaKe BeTtEr PhOtOs | Jokes and memes |
| InVeRsE | hOW TO TAKE BETTER PHOTOS | Undoing reversed Caps Lock |
Every conversion keeps your line breaks, so a list of 50 headlines or column names converts in one go.
How title case works
Title case is not “capitalize every word”. Style guides agree on most of the rules:
- Always capitalize the first and the last word.
- Capitalize the first word after a colon or a dash, because it starts a new phrase.
- Capitalize nouns, verbs (including short ones like “Is” and “Be”), adjectives, adverbs and pronouns.
- Lowercase articles (a, an, the) and the conjunctions and, but, or, nor and for.
They disagree about prepositions and a few short words. The Chicago Manual of Style lowercases prepositions of any length. AP style, used by many newsrooms, capitalizes every word of four letters or more and lowercases shorter conjunctions such as “so” and “yet”.
| Words | Chicago | AP |
|---|---|---|
| a, an, the | lowercase | lowercase |
| and, but, or, nor, for | lowercase | lowercase |
| so, yet | Capitalized | lowercase |
| Short prepositions: in, of, on, at, to | lowercase | lowercase |
| Long prepositions: with, about, through | lowercase | Capitalized |
Worked example: “a guide to living with less: what to keep and what to give away” becomes
- Chicago: A Guide to Living with Less: What to Keep and What to Give Away
- AP: A Guide to Living With Less: What to Keep and What to Give Away
Only “with” changes. “What” is capitalized in both because it follows the colon, and “Away” because it is the last word.
A few more details the converter handles for you. Hyphenated words get a capital on each part, but small words inside stay small, so “state-of-the-art” becomes “State-of-the-Art”. Words that already contain a capital after the first letter, such as NASA, HTML5, iPhone or McDonald, are left alone, because those capitals are deliberate. Links and email addresses are never touched.
One thing no converter can do perfectly: Chicago capitalizes a preposition when it works as an adverb, as in “Look Up” or “Turn Off”. The tool can’t read meaning, so check phrasal verbs like these by hand.
Sentence case and Caps Lock text
Sentence case lowercases the text, then capitalizes the first letter of each sentence, each new line, and the word “I” (including I’m, I’ve, I’ll and I’d). Abbreviations such as “e.g.” and “Dr.” don’t count as the end of a sentence.
It is the quickest fix for text typed with Caps Lock on. When almost every letter is a capital, the converter knows the capitals were not deliberate and treats the words normally instead of keeping them as acronyms.
The limit is proper nouns. “PARIS IN MAY” becomes “Paris in may” because the tool can’t know that May is a month here, and a name in the middle of a sentence ends up lowercase. Read the result once and fix names, places and brands.
How the programming cases split words
camelCase, snake_case and the other programming styles first break your text into words, then join them with the right separator. The splitter understands:
- spaces, punctuation, underscores, hyphens, dots and slashes;
- existing camel “humps”: “userName” splits into user and name;
- runs of capitals: “XMLHttpRequest” splits into XML, Http and Request, giving
xml_http_requestorxmlHttpRequest; - letters with accents, which are kept as they are.
Apostrophes are dropped rather than turned into separators, so “don’t stop” becomes dontStop and not donTStop.
Tips
- Use kebab-case for URLs and file names. Lowercase avoids trouble on servers that treat “Photo.jpg” and “photo.jpg” as different files.
- Pick one heading style and stick to it. Mixed title case and sentence case on one page looks careless.
- Renaming JSON keys? Check the result is still valid with the JSON formatter.
- Watch the length. Headlines often have limits; the character counter shows how much room is left on X, in search results and in an SMS.
- Want decorative letters instead? The font generator turns text into bold, script and other Unicode styles for bios.
Everything runs in your browser. Your text is not uploaded, and the draft is kept only in your own browser until you press Clear.