How to use the case converter
Paste your text and press a button. The conversion replaces the text in the box, so you can chain them — lower case, then Title Case — and step back with Undo (or Ctrl+Z) at any point. Select part of the text first and only that part changes, which is ideal for fixing one heading in a longer document. Character, word, sentence and line counts under the box update as you go; for the full breakdown with platform limits, use the character counter.
Keep acronyms is on by default, so NASA, BBC and UK survive sentence case and Title Case, and mixed-case brand names such as iPhone and eBay are left alone in titles. Turn it off to force every word through the same rule — useful when the source text was typed with Caps Lock on.
Title Case rules by style guide
“Title Case” is not one rule. Every style guide capitalises the first and last word and all nouns, verbs, adjectives and adverbs; they disagree about the small words in between.
| Style | Kept lowercase | Example |
|---|---|---|
| Chicago | Articles, and/but/for/or/nor, and all prepositions, whatever their length | A Walk through the Woods without a Map |
| AP | Articles, conjunctions and prepositions of three letters or fewer | A Walk Through the Woods Without a Map |
| APA | Short (three letters or fewer) articles, conjunctions and prepositions; both halves of hyphenated compounds capitalised | A Walk Through the Woods Without a Map |
| MLA | Articles, all prepositions, coordinating conjunctions and the to in infinitives | A Walk through the Woods without a Map |
The word after a colon or dash is always capitalised, as the start of a subtitle. Untick keep small words lowercase to capitalise every word, which is what many YouTube titles and some house styles use. The converter cannot know that a word such as up is part of a phrasal verb (“Set Up Your Account”), where the guides capitalise it, so give headlines a final read.
camelCase, snake_case and other programming cases
| Case | Example | Typical use |
|---|---|---|
| camelCase | userAccountId | JavaScript and Java variables and functions |
| PascalCase | UserAccountId | Classes, React components, C# methods |
| snake_case | user_account_id | Python, Ruby, database columns |
| CONSTANT_CASE | USER_ACCOUNT_ID | Constants and environment variables |
| kebab-case | user-account-id | CSS classes, file names, command-line flags |
| dot.case | user.account.id | Config keys, translation keys |
| Train-Case | User-Account-Id | HTTP headers |
The converter first breaks the input into words — at spaces, punctuation, underscores and hyphens, and at the boundaries inside existing camelCase and PascalCase (XMLHttpRequest becomes xml http request) — then joins them in the chosen style, so you can convert freely between them. With one identifier per line ticked, each line of a list becomes its own identifier. Convert accents to plain ASCII turns café into cafe and Straße into strasse, because most languages and systems only accept ASCII in names.
URL slugs and language-specific casing
Slugify produces a web address segment: lower case, ASCII only, words joined by hyphens, with & spelt out as and. Accents are transliterated rather than dropped, and Cyrillic and Greek letters are romanised, so “Crème Brûlée & Café” becomes creme-brulee-and-cafe and “Привет мир” becomes privet-mir. Keep slugs short and descriptive; a slug is part of the page’s address and is hard to change once people link to it.
Upper and lower case are not the same in every language. In Turkish and Azerbaijani, the capital of i is İ and the lower case of I is ı; with the default rules, “istanbul” would wrongly become “ISTANBUL” without the dot. Choose the language under Language rules to get it right. Dutch capitalises the IJ digraph together (IJsselmeer), German ß becomes SS in capitals, and Greek drops accents and uses the final sigma correctly. Reversed or decorative text is a job for the reverse text generator instead.
Frequently asked questions
What is the difference between Title Case and Capitalised Case?
Capitalised Case puts a capital at the start of every single word, including “a”, “of” and “the”. Title Case follows a style guide: it capitalises the important words but keeps short articles, conjunctions and prepositions in lower case unless they are the first or last word, as in “The Lord of the Rings”.
Which Title Case style should I use?
Use whatever your publication or organisation follows. News and PR writing in the US usually follows AP; books and many websites use Chicago; academic papers use APA or MLA according to the discipline. If you have no house style, Chicago is the most widely recognised. The differences mostly concern prepositions of four letters or more.
How do I convert only part of my text?
Select the words you want to change in the text box, then press a case button. Only the selection is converted and it stays selected, so you can try another case straight away. Press Undo to reverse the change. Without a selection, the whole text is converted.
Why did “istanbul” become “ISTANBUL” without the dot?
Because standard English casing rules were applied. In Turkish, lower-case i with a dot has the capital İ, and I without a dot has the lower case ı. Select Turkish (or Azerbaijani) under Language rules and upper case gives İSTANBUL, while lower case turns “ISPARTA” into “ısparta” correctly.
Does converting to sentence case keep names and acronyms?
It keeps acronyms written in capitals, such as NASA or UK, when Keep acronyms is ticked, and it always capitalises the word I. It cannot recognise ordinary proper nouns, so names like London or Sarah will be lowercased if they are not at the start of a sentence. Fix those by hand, or select just the sentences you want to change.