What does NFC normalisation do?

NFC stands for Normalization Form C, or Canonical Composition. It first canonically decomposes the text, then recomposes combining marks onto their base letters, producing the shortest canonically equivalent representation.

Why would two visually identical strings not be equal?

The letter e-acute can be stored as one precomposed code point (U+00E9) or as a base e plus a combining accent (U+0065 U+0301). They look the same but are different byte sequences. NFC normalises both to the precomposed form so comparisons succeed.

When should I use NFC?

NFC is the recommended default for storing and transmitting text on the web. The W3C recommends NFC for HTML and most databases, identifiers, and APIs expect it because it is compact and stable.

Does NFC change the meaning of my text?

No. NFC only changes the encoding, not the visible characters. The result is canonically equivalent, so it renders identically while using the standard composed form.

Is my text uploaded anywhere?

No. Normalisation uses the browser's built-in Unicode engine via String.prototype.normalize, so everything happens locally and nothing is sent to a server.

Unicode NFC Normaliser

Unicode lets the same visible character be encoded in more than one way. NFC (Normalization Form C) collapses these alternatives into a single canonical composed form, which is the encoding the web recommends for storage and transmission. This tool applies NFC and shows you the code points before and after so you can see exactly what changed.

How it works

NFC is defined as a canonical decomposition followed by a canonical composition:

1. Canonical Decompose  é  ->  e + ◌́   (U+0065 U+0301)
2. Canonical Compose     e + ◌́  ->  é   (U+00E9)

The decomposition step puts everything into a fully separated, ordered form; the composition step then merges combining marks back onto their base characters wherever a precomposed code point exists. The result is the shortest canonically equivalent string. The tool relies on the engine’s native String.prototype.normalize("NFC"), which implements the full Unicode normalisation algorithm.

Notes and example

If you paste e followed by a combining acute accent, the output is the single character é (U+00E9) and the code point count drops by one. Text that is already composed is returned unchanged. Use NFC before storing user input or comparing identifiers so that visually identical names always match. For the opposite operation see the NFD decomposer.