﻿---
title: kuromoji analyzer
description: The kuromoji analyzer uses the following analysis chain: CJKWidthCharFilter from Lucene, kuromoji_tokenizer, kuromoji_baseform token filter, kuromoji_part_of_speech...
url: https://www.elastic.co/elastic/docs-builder/docs/2423/reference/elasticsearch/plugins/analysis-kuromoji-analyzer
---

# kuromoji analyzer
The `kuromoji` analyzer uses the following analysis chain:
- `CJKWidthCharFilter` from Lucene
- [`kuromoji_tokenizer`](https://www.elastic.co/elastic/docs-builder/docs/2423/reference/elasticsearch/plugins/analysis-kuromoji-tokenizer)
- [`kuromoji_baseform`](https://www.elastic.co/elastic/docs-builder/docs/2423/reference/elasticsearch/plugins/analysis-kuromoji-baseform) token filter
- [`kuromoji_part_of_speech`](https://www.elastic.co/elastic/docs-builder/docs/2423/reference/elasticsearch/plugins/analysis-kuromoji-speech) token filter
- [`ja_stop`](https://www.elastic.co/elastic/docs-builder/docs/2423/reference/elasticsearch/plugins/analysis-kuromoji-stop) token filter
- [`kuromoji_stemmer`](https://www.elastic.co/elastic/docs-builder/docs/2423/reference/elasticsearch/plugins/analysis-kuromoji-stemmer) token filter
- [`lowercase`](https://www.elastic.co/elastic/docs-builder/docs/2423/reference/text-analysis/analysis-lowercase-tokenfilter) token filter

It supports the `mode` and `user_dictionary` settings from [`kuromoji_tokenizer`](https://www.elastic.co/elastic/docs-builder/docs/2423/reference/elasticsearch/plugins/analysis-kuromoji-tokenizer).

## Normalize full-width characters

The `kuromoji_tokenizer` tokenizer uses characters from the MeCab-IPADIC dictionary to split text into tokens. The dictionary includes some full-width characters, such as `ｏ` and `ｆ`. If a text contains full-width characters, the tokenizer can produce unexpected tokens.
For example, the `kuromoji_tokenizer` tokenizer converts the text `Ｃｕｌｔｕｒｅ ｏｆ Ｊａｐａｎ` to the tokens `[ culture, o, f, japan ]` instead of `[ culture, of, japan ]`.
To avoid this, add the [`icu_normalizer` character filter](https://www.elastic.co/elastic/docs-builder/docs/2423/reference/elasticsearch/plugins/analysis-icu-normalization-charfilter) to a custom analyzer based on the `kuromoji` analyzer. The `icu_normalizer` character filter converts full-width characters to their normal equivalents.
First, duplicate the `kuromoji` analyzer to create the basis for a custom analyzer. Then add the `icu_normalizer` character filter to the custom analyzer. For example:
```json

{
  "settings": {
    "index": {
      "analysis": {
        "analyzer": {
          "kuromoji_normalize": {                 <1>
            "char_filter": [
              "icu_normalizer"                    <2>
            ],
            "tokenizer": "kuromoji_tokenizer",
            "filter": [
              "kuromoji_baseform",
              "kuromoji_part_of_speech",
              "cjk_width",
              "ja_stop",
              "kuromoji_stemmer",
              "lowercase"
            ]
          }
        }
      }
    }
  }
}
```