Unicode Normalizer

Normalize text to a chosen Unicode normalization form.

Description

Normalize text to NFC, NFD, NFKC, or NFKD for consistent Unicode representation.

Visually identical text can have different code-point sequences. Unicode normalization provides defined canonical and compatibility forms for consistent storage and comparison.^[1]

When to use Unicode Normalization Tool

Normalize imported text before binary comparison
Inspect composed and decomposed accents
Apply compatibility normalization to controlled identifiers

How the calculation works

NFD canonically decomposes and NFC recomposes where possible. NFKD and NFKC also apply compatibility decomposition, which can erase distinctions such as width variants and ligatures.^[1]

Interpreting the result

Text can look unchanged despite a different encoding. Compatibility forms are more destructive than canonical forms and should be selected according to the target protocol.

Important limitations

Normalization is not transliteration, case folding, or confusable detection.
Compatibility forms can erase semantically important formatting distinctions.
Concatenated normalized strings may need normalization again.

References

Unicode Standard Annex #15: Unicode Normalization Forms — Unicode Consortium