CSS Case Fold Demo

This page demonstrates ACI and Unicode CF case folding as described here:CaseForCaseless

First, some buttons that demonstrate doing the case folds:

Click here to see UniCF implementation in JavaScript.

Enter your string to case fold:

TypeFolded ValueCode Points
ACI
Unicode C+F

Examples of each now follow. The "non-matching" version of "grun" uses the combining mark U+0308 and thus illustrates how normalization (or lack thereof) breaks matching.

The test items are:

  1. "GRÜN","grün","grÜn": case variants of the German word.
  2. "grün": uses U+0308 to add the umlaut to the 'u'. Not in Form NFC.
  3. "groß","gross","GROSS": case variants of the German word.
  4. "GROẞ": uses the uppercase sharp-S (U+1E9E)
  5. "ıI": dotless I
  6. "iI","Ii","II": other (regular) I cases
  7. "русски","РУССКИ","Русски": case variants in Cyrillic

ASCII Case Insensitive vs. Unicode C+F Matching

Items with 'A' match in an ASCII case-insensitive manner.

Items with 'U' match in a Unicode "common" plus "full" case-insensitive manner.

Items with '▋' have only one of the two ('A' or 'U').