Case converter

How to change text case

1. 1

   Paste or drop your text

   Type into the box, paste from anywhere, or drop a .txt, .md or .csv file up to 5 MB.

2. 2

   Pick a case

   Eight of them. The result updates while you type; there is no button to press.

3. 3

   Copy or download

   One click for the clipboard, one for a .txt file.

Why case conversion is not just toUpperCase

It is in English, and nowhere else. Turkish has two separate letters where English has one: the dotted i uppercases to İ, not I, and getting this wrong turns Turkish words into different Turkish words. German ß uppercases to SS, and that change is one-way, because SS lowercased comes back as ss, not ß. Greek final sigma changes shape depending on where it sits in the word. This page uses locale-aware conversion and lets you name the language explicitly, and it warns you before the ß conversion rather than after you have already pasted the result somewhere.

Sentence case and the abbreviation problem

Sentence case means lowercasing everything and then capitalising the first letter of each sentence, which requires knowing where sentences end. A naive split on full stops breaks on "Dr. Smith", on "e.g.", and on "3.14". This page carries a list of two dozen common abbreviations and treats a full stop between two digits as a decimal point, so those cases survive. Acronyms are handled separately: NASA and PDF stay as they are rather than becoming Nasa and Pdf, unless you turn that off.

Title case, APA style

There are several title case conventions and they disagree. The one used here is APA's: capitalise every word except a short list of articles, conjunctions and prepositions (a, an, the, and, but, or, of, to, in and about twenty more), while always capitalising the first and last word regardless. That last rule is what separates a real title case from a naive one, and it is why "The Book of the Dead" comes out right rather than as "The Book Of The Dead" or "the Book of the dead". If you would rather have every word capitalised, that is the other option.

The programmer cases

camelCase, PascalCase, snake_case and kebab-case all need the same first step: working out where one word ends and the next begins. This page treats spaces, dashes, underscores and dots as boundaries, and also the point where a lowercase letter is followed by an uppercase one. That single extra rule is what lets it read helloWorldExample as three words rather than one, so converting between the four programmer cases works in both directions rather than only away from spaces.

Nothing is uploaded, and nothing needs to load

This is plain JavaScript with no libraries behind it, so the page works on a first visit, on a phone, and with the network switched off. There is no upload, no queue and no processing on anybody's server, which is also why there is no limit on how many times you can use it.

Frequently asked questions