Case Converter
Switch text between UPPERCASE, lowercase, Title Case, Sentence case and programmer formats like camelCase and snake_case.
🔒 Runs entirely in your browser. Nothing you enter is sent to a server.
Retyping a paragraph because Caps Lock was on, or fixing a headline that came out in all caps, is a waste of time. This case converter changes the capitalization of any amount of text in one click. It covers the everyday writing styles and the naming formats developers use in code.
How to use the case converter
- Paste or type your text into the left box, or click Try an example.
- Choose a format under Convert to. The result appears on the right immediately.
- Click Copy result. To apply a second conversion, click Use output as input.
Every format explained
| Format | Example | Typical use |
|---|---|---|
| UPPERCASE | THE QUICK BROWN FOX | Acronyms, warnings, short labels |
| lowercase | the quick brown fox | Normalizing data, hashtags, emails |
| Title Case | The Quick Brown Fox | Headlines, book and song titles |
| Sentence case | The quick brown fox | Body text, UI buttons, subject lines |
| camelCase | theQuickBrownFox | JavaScript and Java variables |
| PascalCase | TheQuickBrownFox | Class and component names |
| snake_case | the_quick_brown_fox | Python, SQL columns, file names |
| kebab-case | the-quick-brown-fox | URLs, CSS classes, CLI flags |
| CONSTANT_CASE | THE_QUICK_BROWN_FOX | Constants, environment variables |
| aLtErNaTiNg | tHe qUiCk bRoWn fOx | Memes and playful text |
Title case rules in short
English style guides disagree on details, but most share a core set of rules, and this tool follows them:
- Always capitalize the first and last important words and any word after a colon.
- Capitalize nouns, verbs, adjectives, adverbs and pronouns, even short ones like “Is” and “It”.
- Keep articles (a, an, the), short conjunctions (and, but, or, nor) and short prepositions (in, on, at, of, to, by) in lowercase.
For example, “a guide to the best hiking trails in the alps” becomes “A Guide to the Best Hiking Trails in the Alps”. Remember to capitalize proper nouns like “Alps” by hand when you use sentence case.
Why not just use Caps Lock or Word?
Word processors can change case, but they rarely offer programmer formats like snake_case or kebab-case, and their title case usually capitalizes every single word. This tool works on any device, handles many lines at once, and treats each line separately for code formats. That makes it handy for converting a whole list of field names in one go.
Frequently asked questions
What is the difference between Title Case and Sentence case?
Title Case capitalizes the first letter of most words, as in "The Lord of the Rings". Sentence case capitalizes only the first word of each sentence, plus proper nouns, as in "The lord of the rings". Headlines usually use title case, and body text and many modern UI labels use sentence case.
Which words stay lowercase in Title Case?
This tool keeps short articles, conjunctions and prepositions, such as a, an, the, and, but, of, in, on and to, in lowercase unless they start the title or follow a colon. That follows the common rule shared by most English style guides.
Will sentence case capitalize names like London or Sarah?
No. A tool can't reliably tell proper nouns from ordinary words, so sentence case lowercases everything except the first letter of each sentence. Re-capitalize names afterwards.
What are camelCase, snake_case and kebab-case used for?
They are naming conventions in programming. camelCase is common for JavaScript and Java variables, PascalCase for class names, snake_case for Python and database columns, kebab-case for URLs and CSS classes, and CONSTANT_CASE for constants and environment variables.