How to use the Case Converter
- Paste or type your text into the left box.
- Pick a case from the buttons above, such as Title Case or snake_case. The result updates as you type.
- Click Copy result or download it as a text file.
- To apply a second conversion, click Use as input and choose another case.
Features
- Twelve cases, including Title Case with proper small-word rules
- Programming styles: camelCase, PascalCase, snake_case, kebab-case and CONSTANT_CASE
- Keeps acronyms and brand names such as NASA and iPhone in title case
- Converts each line separately, so lists stay lists
- Copy, download or feed the result back in for another pass
- Works with accented and non-Latin letters
Which case should you use?
| Case | Example | Typical use |
|---|---|---|
| Title Case | The Lord of the Rings | Headlines, book and article titles |
| Sentence case | The lord of the rings | Body text, UI labels, many style guides’ headings |
| UPPERCASE | THE LORD OF THE RINGS | Short labels, warnings, acronyms |
| camelCase | lordOfTheRings | JavaScript and Java variables and functions |
| PascalCase | LordOfTheRings | Class names, React components, C# methods |
| snake_case | lord_of_the_rings | Python variables, database columns |
| kebab-case | lord-of-the-rings | URLs, CSS class names, file names |
| CONSTANT_CASE | LORD_OF_THE_RINGS | Constants and environment variables |
How Title Case works here
Title case is not simply capitalizing every word. Most style guides keep short function words lowercase unless they start or end the title: articles (a, an, the), coordinating conjunctions (and, but, or, nor, for, so, yet) and short prepositions (at, by, in, of, on, to, up, via and similar). This converter follows that rule, always capitalizes the first and last word, and capitalizes the first word after a colon or dash so subtitles look right: “Notes from the Field: A Guide to Remote Work”.
Words that already contain a capital after the first letter, such as NASA, iPhone or McDonald, are left alone, because they are acronyms or brand names. If your whole text is in capitals, it is treated as having no case information and converted normally.
Style guides differ in the details. AP style capitalizes every word of four letters or more, so it writes “With” and “From”, while Chicago lowercases prepositions of any length. This tool keeps with, from, into and onto lowercase. If you follow AP, adjust those few words by hand, or use Capitalize Each Word when you simply want every word capitalized.
Sentence case and proper nouns
Sentence case lowercases everything, then capitalizes the first letter of each sentence and each new line, and fixes the pronoun “I”. It cannot know which words are names, so “paris” and “google” stay lowercase. Read the result once and restore capitals for names and places.
Naming styles for code
The programming cases split your text into words at spaces, punctuation and existing capital letters, so “Customer ID number”, “customer-id-number” and “customerIdNumber” all become the same words. Apostrophes are dropped (“don’t stop” becomes dontStop) and digits are kept. Each line is converted on its own, which lets you paste a whole column of field names and convert them in one go. For web addresses, the Slug Generator also strips accents and unsafe characters.
Fixing text typed with Caps Lock on
If you typed a paragraph with Caps Lock accidentally on, it looks like “hELLO tHERE”. Choose iNVERSE to swap every letter’s case and get “Hello There” back without retyping. Alternating case, the “mocking” style from memes, is fun for social posts but hard to read and poorly handled by screen readers, so avoid it for anything important.
Frequently asked questions
How do I change capital letters to lowercase without retyping?
Paste the text and click lowercase, or Sentence case if you want each sentence to start with a capital. Then copy the result.
What is the difference between Title Case and Capitalize Each Word?
Title Case keeps short words such as “of”, “and” and “the” lowercase in the middle of a title, as style guides recommend. Capitalize Each Word capitalizes every word without exceptions.
Will it keep acronyms like NASA or brand names like iPhone?
In Title Case and Capitalize Each Word, yes: words that already contain a capital after their first letter are left as they are. Other cases convert every letter.
What happens to punctuation in camelCase or snake_case?
Punctuation and spaces become word breaks and are removed, apostrophes are dropped, and letters and digits are kept. Each line is converted separately.
Is my text sent to a server?
No. The conversion runs in your browser, so nothing you paste leaves your device.