[[analysis-normalizers]] == Normalizers beta[] Normalizers are similar to analyzers except that they may only emit a single token. As a consequence, they do not have a tokenizer and only accept a subset of the available char filters and token filters. Only the filters that work on a per-character basis are allowed. For instance a lowercasing filter would be allowed, but not a stemming filter, which needs to look at the keyword as a whole. The current list of filters that can be used in a normalizer is following: `arabic_normalization`, `asciifolding`, `bengali_normalization`, `cjk_width`, `decimal_digit`, `elision`, `german_normalization`, `hindi_normalization`, `indic_normalization`, `lowercase`, `persian_normalization`, `scandinavian_folding`, `serbian_normalization`, `sorani_normalization`, `uppercase`. [float] === Custom normalizers Elasticsearch does not ship with built-in normalizers so far, so the only way to get one is by building a custom one. Custom normalizers take a list of char <<analysis-charfilters, character filters>> and a list of <<analysis-tokenfilters,token filters>>. [source,js] -------------------------------- PUT index { "settings": { "analysis": { "char_filter": { "quote": { "type": "mapping", "mappings": [ "« => \"", "» => \"" ] } }, "normalizer": { "my_normalizer": { "type": "custom", "char_filter": ["quote"], "filter": ["lowercase", "asciifolding"] } } } }, "mappings": { "type": { "properties": { "foo": { "type": "keyword", "normalizer": "my_normalizer" } } } } } -------------------------------- // CONSOLE