What each case style is for
Case conventions carry meaning — different communities settled on different styles for good reasons, and mixing them up stands out as an error. Here is what each output is used for.
- UPPER CASE
- Constants in many languages (
MAX_RETRIES,PI), environment variables, headings that must shout, and acronyms. Also used in legal documents for emphasis. - lower case
- Default for most prose input, filenames on case-sensitive file systems, and normalisation before comparison or search.
- Title Case
- Book titles, article headlines, chapter headings, and proper nouns. Every word starts with a capital letter.
- Sentence case
- Normal prose, UI labels, and button text. Only the first word of each sentence is capitalised — everything else stays lower.
- camelCase
- Variable and function names in JavaScript and Java (
getUserName,totalPrice). The first word is lower-case; every subsequent word starts with a capital. - snake_case
- Variable names in Python (
user_name), database column names (created_at), and many Unix shell scripts. Words are joined by underscores, all lower-case. - kebab-case
- URL slugs (
/text/case-converter), CSS class names (.hero-section), and HTML attributes. Words are joined by hyphens, all lower-case. Hyphens are URL-safe without encoding.
Worked example
Input: hello world
| Format | Result |
|---|---|
| UPPER CASE | HELLO WORLD |
| lower case | hello world |
| Title Case | Hello World |
| Sentence case | Hello world |
| camelCase | helloWorld |
| snake_case | hello_world |
| kebab-case | hello-world |
Frequently asked
Does it handle punctuation and numbers?
Yes. Punctuation is preserved in upper, lower, title and sentence case. For camelCase, snake_case and kebab-case, non-alphanumeric characters act as word boundaries and are then removed, so only letters and digits appear in the output.
What about accented characters?
The converter uses the browser’s built-in toUpperCase() and toLowerCase(), which handle accented letters correctly for the Unicode Basic Multilingual Plane.
Is anything sent to a server?
No. All conversion happens in your browser. Nothing you type is transmitted anywhere.