JavaScript .normalize()

The .normalize() method in JavaScript returns the Unicode Normalization Form of a string. This is especially useful when comparing strings that may look identical but are composed of different Unicode code points.

Syntax

string.normalize([form])

Parameters:

• form (Optional): A string specifying the Unicode normalization form. Valid values are:
  • 'NFC' (Default): Canonical Composition
  • 'NFD': Canonical Decomposition
  • 'NFKC': Compatibility Composition
  • 'NFKD': Compatibility Decomposition

Return value:

A new string in the specified normalization form.

Example: Comparing Unicode Representations

In this example, two visually identical strings have different Unicode encodings, and .normalize() is used to make them comparable:

const word1 = '\u00e9'; // é as single character
const word2 = '\u0065\u0301'; // e + ́ (combining acute)

console.log(word1 === word2);
console.log(word1.normalize() === word2.normalize());

Copy to clipboard
Copy to clipboard

The output of this code is:

false
true

Copy to clipboard
Copy to clipboard

Codebyte Example: Stripping Accents Using Normalize + Regex

In this codebyte example, .normalize() is combined with a regular expression to strip accents by removing Unicode diacritical marks:

Visit us
Visit us
Hide code
Code
Output
Hide output
Loading...
Copy to your clipboard
Copy Codebyte
Run