RangeError: form must be one of 'NFC', 'NFD', 'NFKC', or 'NFKD'

This is a reference entry from MDN Web Docs. A full explanation with fixes has not been written yet.

The error messages

RangeError: The normalization form should be one of NFC, NFD, NFKC, NFKD. (V8-based)

As listed by MDN Web Docs

RangeError: form must be one of 'NFC', 'NFD', 'NFKC', or 'NFKD' (Firefox)

As listed by MDN Web Docs

RangeError: argument does not match any normalization form (Safari)

As listed by MDN Web Docs

Different error? Paste it

or press Cmd/Ctrl + Enter. The text is only sent to this site to match it.

Source: MDN Web Docs. Data fetched 2026-09-25T01:48:37.273Z.