UPPERCASE Converter
Convert any text to UPPERCASE instantly. Free, no signup, runs entirely in your browser.
About UPPERCASE Converter
The UPPERCASE converter transforms every letter in your text to its capital form. It uses JavaScript's String.prototype.toUpperCase(), which is Unicode-aware: it correctly handles characters from non-Latin alphabets such as Greek, Cyrillic, and accented Latin characters. The conversion happens locally in your browser — your text is never sent to a server.
When to use it
- Formatting titles, headlines, or headings for consistency
- Normalizing user input before comparing strings (e.g. email matching)
- Preparing constants for code (SQL keywords, environment variable names)
- Emphasizing a word or phrase in a chat, email, or social post
- Converting database field names or HTTP header names to a uniform style
How it works
Each character is mapped to its uppercase counterpart according to the Unicode case-mapping tables built into your browser's JavaScript engine. Characters with no uppercase form (digits, punctuation, symbols, ideographs) are passed through unchanged. The operation is locale-independent by default — if you need locale-specific behavior (such as Turkish dotless I), the underlying API supports it via toLocaleUpperCase().
Examples
Hello, world!
HELLO, WORLD!
café naïve résumé
CAFÉ NAÏVE RÉSUMÉ
user_id, created_at, is_active
USER_ID, CREATED_AT, IS_ACTIVE
Frequently asked questions
- Is my text uploaded to a server?
- No. All conversion happens in your browser via JavaScript. Your input never leaves your device.
- Does it handle non-English characters?
- Yes. It uses Unicode case mapping, so accented Latin characters (é → É), Greek (α → Α), Cyrillic (д → Д), and other scripts with case are converted correctly. Scripts without case (Arabic, Hebrew, CJK ideographs) are passed through unchanged.
- What about the German sharp S (ß)?
- Modern JavaScript engines convert ß to SS (the historically standard uppercase form). The Unicode standard also defines a capital ẞ as of 2017, but most engines still prefer SS for compatibility.
- Is there a character limit?
- No fixed limit. The browser handles documents of millions of characters without issue. Very large inputs (tens of megabytes) may briefly slow the UI as the textarea re-renders.
- How is this different from CSS text-transform: uppercase?
- CSS only changes how text is displayed — the underlying characters remain lowercase. This tool changes the actual characters, so you can copy the uppercase result and paste it elsewhere.