Upper, lower, title, sentence, camel, snake and kebab case.
What it's for
Change the capital letters in a piece of text — all capitals, all small letters, a proper title — or turn a phrase into a name a programmer can use, such as my_file_name.
Before you start
Have the text ready to copy: a heading, a list of names typed all in capitals, or a phrase you need as a file name. It is changed here in your browser and is not sent anywhere.
Put in your text
Type or paste it into the Text box. The box already holds a sample sentence, so select it all and replace it.
Choose a style
In Style, pick how the text should look. Sentence case puts a capital only at the start of each sentence, which suits ordinary writing. Title Case capitalises most words, for a heading. UPPER CASE and lower case change every letter.
Pick a programmer's style, if you need one
camelCase, snake_case, kebab-case and the styles near them join the words into one name with no spaces, for a file name or for code. They keep only letters and numbers, so punctuation is dropped.
Convert and copy
Press Convert to bring the answer into view — it also changes as you type. Press Copy at the top to take it, then paste it where you need it.
Reading the result
If it goes wrong
Only one of these is hard: title case. And it is hard because there is no single right answer — the style guides genuinely disagree about which small words stay lower case.
So the list is published rather than hidden. A tool that quietly picks a house style and calls the result "title case" is making an editorial decision on your behalf without telling you.
One thing every guide agrees on: the first and last word are always capitalised, whatever the list says.
For the identifier styles, it splits an existing camelCase hump. Without that, theQuickBrownFox becomes thequickbrownfox — and the split is what makes converting between them work in both directions.
Articles, short conjunctions and short prepositions: a, an, the, and, but, or, nor, for, yet, so, as, at, by, in, of, off, on, per, to, up, via, from, into, onto, over, with. The first and last word of a title are always capitalised whatever the list says, which every style guide agrees on. Guides genuinely disagree about the rest — some capitalise prepositions of five letters or more — so this page prints the list it uses rather than presenting one house style as the answer.
Title case capitalises most words: The Quick Brown Fox. Sentence case capitalises only the first word of each sentence and anything that is a proper noun: The quick brown fox. Sentence case is what most style guides now prefer for headings, because it is easier to read and easier to get right.
It should not — this splits on an existing camelCase hump, so theQuickBrownFox becomes the_quick_brown_fox rather than thequickbrownfox. That split is what makes converting between identifier styles work in both directions.
They are kept. Converting Señor to lower case gives señor, and to kebab-case gives señor — not senor. Identifiers in most modern languages allow non-ASCII characters, and stripping them silently would change a name rather than its case. If you want them transliterated for a URL, use the Slug Generator, which does that deliberately and tells you it did.
No. A line break inside a paragraph is not a new sentence, and treating it as one mangles wrapped prose. Capitalisation happens after a full stop, question mark or exclamation mark, and at the very start of the text.
All ten are shown at once because the comparison is usually the question.
Señor becomes señor, not senor. Identifiers in most modern languages allow non-ASCII, and stripping it silently changes a name rather than its case. If the destination is a URL, use the Slug Generator — it does that deliberately, and says it did.
Important
Runs entirely in your browser. Title case has no single correct answer — the list of words kept lower case is printed on this page so you can see which convention was applied. Nothing you type here is sent to our servers — the calculation runs entirely in your browser.
