Uppercase Converter
Uppercase Converter calls toLocaleUpperCase on the entire input. Romanian letters such as ă, â, î, ș, and ț are handled by Unicode case mapping, while digits and punctuation remain. Uppercasing is not always one character to one character—some mappings expand—and the result can depend on the browser's current locale. It does not alter meaning-aware acronyms or preserve mixed brand casing.
Runs locally — files stay on your deviceCan uppercase conversion change string length?
Yes. Some Unicode mappings expand into multiple characters.
Unicode casing is more than ASCII
Case mappings are defined per Unicode character and locale; they are not guaranteed to be reversible or length-preserving.
How it works
The whole JavaScript string is passed to String.toLocaleUpperCase().
Key concepts
Locale-sensitive mapping
Results can vary for languages such as Turkish.
Expansion
One lowercase character can produce more than one uppercase character.
When to use it
- Normalize text for a visual label.
- Create an uppercase comparison copy.
- Convert Romanian and other Unicode letters.
When not to use it
- Do not use casing as a locale-independent identifier policy.
- Do not expect original brand/acronym casing.
- Do not assume converting back restores the exact source.
Worked examples
Romanian
- Input
învăț română- Expected output
ÎNVĂȚ ROMÂNĂ
Diacritics uppercase.
Punctuation
- Input
q2-report!- Expected output
Q2-REPORT!
Nonletters remain.
Mixed brand
- Input
iPhone- Expected output
IPHONE
Original styling is lost.
Common mistakes
Using as identity normalization
Locale and expansion matter. Correction: Use a specified case-folding protocol.
Expecting reversible conversion
Case distinctions are lost. Correction: Keep the source.
Ignoring proper nouns
All letters change. Correction: Review editorial output.
Best practices
- Keep original text.
- Apply a stated locale policy in production.
- Review names and identifiers.
Related operations and differences
Add Prefix to Every Line
Choose Add Prefix to Every Line when you need to add the same prefix before every line.; use Uppercase Converter specifically for uppercase.
Add Suffix to Every Line
Choose Add Suffix to Every Line when you need to add the same suffix after every line.; use Uppercase Converter specifically for uppercase.
Capitalize Every Word
Choose Capitalize Every Word when you need to capitalize the first character of every word.; use Uppercase Converter specifically for uppercase.
Extract Email Addresses
Choose Extract Email Addresses when you need to find unique email addresses in text.; use Uppercase Converter specifically for uppercase.
Extract URLs
Choose Extract URLs when you need to find unique HTTP and HTTPS links in text.; use Uppercase Converter specifically for uppercase.
Line Counter
Choose Line Counter when you need to count the number of text lines.; use Uppercase Converter specifically for uppercase.
Limitations and privacy
- Whole-string locale-aware uppercasing only; no locale selector, exceptions, acronym list, word policy, reversible mapping, or typography controls.
Text is transformed locally in this browser and is not uploaded by the tool.
Frequently asked questions
Are Romanian diacritics supported?
Yes through Unicode casing.
Are digits changed?
No.
Is conversion reversible?
Not always.
Can length change?
Yes.