Case Converter
Apply a predictable Unicode-aware case style to notes, headings, and pasted text without changing its spacing or layout.
A QUICK WALKTHROUGH
How to use this tool
- Paste up to 100,000 characters.
- Choose lowercase, uppercase, title, sentence, or toggle case.
- Review the result, then copy it or download a TXT file.
Five explicit conversion modes
Lowercase and uppercase use the browser’s default Unicode mappings. Toggle case switches each caseable character independently. Title Case treats runs of Unicode letters, numbers, and combining marks as words, so punctuation and whitespace remain separators. Sentence Case lowercases the text, then uppercases the first cased character at the start and after sentence punctuation.
Structure and Unicode boundaries
Spaces, tabs, line breaks, punctuation, numbers, symbols, and emoji stay in their original positions. Unicode case mappings can expand a character, such as ß becoming SS in uppercase, so output length can exceed input length. The tool accepts up to 100,000 UTF-16 characters and does not preserve all-caps abbreviations or apply language-specific editorial rules.
GOOD TO KNOW
Common questions
Does title case preserve acronyms?
No. Title Case applies the documented word rule and does not infer or preserve abbreviations such as API or NASA.
What counts as a word?
A word is a run of Unicode letters, numbers, or combining marks. Punctuation, symbols, and whitespace stay between words and are not moved.
Can Unicode case conversion change length?
Yes. Default Unicode mappings can expand or contract text, so the output is limited by the 100,000-character input boundary rather than a fixed character-for-character size.