Case Converter

How to convert text case

Type or paste on the left. All nine forms appear on the right at once, and clicking one copies it.

There is deliberately no dropdown. Choosing a format before you can see any of them is the slowest part of every other converter, and half the time you only know which one you want once you have seen it.

Real title case, not capitalised every word

Title case keeps small words lowercase unless they open or close the title.

That is the whole difference between "The Lord of the Rings" and "The Lord Of The Rings", and it is why most converters produce headings that read as though a machine wrote them. Which it did.

The words that stay lowercase are articles, coordinating conjunctions, and prepositions of four letters or fewer: a, an, the, and, but, or, nor, of, in, on, to, up, at, by, for, from, with. Anything longer gets a capital. The first and last word of the title always get one, whatever they are, which is why "Of Mice and Men" opens with a capital O.

The Chicago and AP style guides disagree at the margins, mostly about four letter prepositions. This follows the part they agree on.

Words with a capital inside them are left alone

iPhone, macOS, eBay, JavaScript. That capital is deliberate, so it survives every conversion here.

It is a small thing that gives a converter away instantly. Lowercase the text first, as most do, and there is no way back: you get Iphone and Macos, and you have to fix them by hand every time.

Sentence case is per sentence

A paragraph has more than one sentence in it, and sentence case means one capital at the start of each.

Every full stop, question mark and exclamation mark followed by a space starts a new one, and so does every line break. The standalone "I" is restored too, since lowercasing it is the most visible thing a naive pass does to English.

One thing it gets wrong, and cannot fix without a dictionary: an abbreviation ends in a full stop, so "e.g. this" picks up a capital it should not have. Worth a glance if your text is full of them.

The programmer cases

camelCase, PascalCase, snake_case, kebab-case and CONSTANT_CASE all read the input the same way, which means you can convert between them freely. Paste user_profile_settings and you get userProfileSettings without an intermediate step.

Acronyms are kept whole. HTTPServer splits into HTTP and Server, not into five separate letters, which is what a naive camel-hump split does.

What often comes next

If the text is heading into a URL rather than into code, the slug generator is the one you want: it lowercases, folds the accents and drops the punctuation in a single step, which is three of these forms at once and none of them quite.

Text that came out of a document or a model carries curly quotes, hidden characters and non-breaking spaces that survive every case change, because none of them have a case. The AI text cleaner strips those in one pass.

If it arrived as markdown, the asterisks and hashes survive too, and worse, they change what counts as a word. The markdown stripper takes those off first.

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