What is UPPERCASE?
UPPERCASE — sometimes called "all caps" — converts every letter in the text to its capital form. It's the loudest, most emphatic capitalization, originally borrowed from inscriptional Latin and now used for emphasis, headers, and identifiers in code.
In digital text, all-caps reads as shouting and is generally avoided for body text. But for short labels, acronyms, and certain code conventions, it's exactly right.
When to use UPPERCASE
- Acronyms and initialisms — NASA, FBI, HTML, JSON.
- Constants and environment variables in code — see CONSTANT_CASE.
- Emphasis — use sparingly. ALL CAPS in body text reads as shouting.
- Section labels in print design where small caps aren't available.
- Headers in tickets, warnings, and labels — DRAFT, URGENT, WARNING.
- Stylistic display type in posters and signage.
How UPPERCASE conversion works
- Every letter is converted to its uppercase form using the browser's Unicode-aware
toLocaleUpperCase()function. - Non-letter characters (digits, punctuation, whitespace) pass through unchanged.
- Locale-specific rules are honored where applicable — for example, the German ß becomes ẞ in modern Unicode, and the Turkish dotless I rule is respected when the browser's locale is Turkish.
Worked examples
| Input | UPPERCASE |
|---|---|
hello world |
HELLO WORLD |
this needs emphasis |
THIS NEEDS EMPHASIS |
mixed CaSe text |
MIXED CASE TEXT |
Related case formats
lowercase
→ Convert text to lowercase
Capitalized Case→ Convert text to Capitalized Case
CONSTANT_CASE→ Convert text to CONSTANT_CASE
Need more conversion options?
Open the full converter →