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Uppercase & Lowercase

Case Converter (Upper & Lowercase)

Convert text between UPPERCASE, lowercase, sentence case, and capitalized words instantly.

Your text is processed locally in your browser. It is never sent to or stored on our servers.
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Guide: Text Case Transformations

This tool lets you transform text between uppercase, lowercase, sentence case, and capitalized words. Processing is executed in your browser with Unicode-aware casing, preserving common characters, accents, and punctuation.

Available Transformations

Format Input Example Output Description
Sentence case hola mundo. ¿qué tal? ¡bien! Hola mundo. ¿Qué tal? ¡Bien! Capitalizes the first letter after sentence starters (. ! ? ¿ ¡ and newlines).
lower case HOLA MUNDO ÁRBOL hola mundo árbol Transforms every character into lowercase letters.
UPPERCASE hola mundo pingüino HOLA MUNDO PINGÜINO Transforms all letters to uppercase (including accents and ñ).
Capitalized Case mañana será otro día Mañana Será Otro Día Capitalizes the first letter of each individual word.

Known Limitations

The Sentence Case converter applies automatic punctuation rules (. ! ? ¿ ¡ and newlines). As a mechanical script without natural language processing, mid-sentence proper names or acronyms (such as NASA) are lowercased.

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