# Lowercase Tokenizer (小写分词器) **`lowercase`**** tokenizer**(小写分词器)，类似于  **[`letter` tokenizer](https://www.elastic.co/guide/en/elasticsearch/reference/5.4/analysis-letter-tokenizer.html "Letter Tokenizer") **，遇到非字母时分割文本，并将所有分割后的词元转为小写。功能上等同于 ** [`letter` tokenizer](https://www.elastic.co/guide/en/elasticsearch/reference/5.4/analysis-letter-tokenizer.html "Letter Tokenizer")** +  **[`lowercase` token filter](https://www.elastic.co/guide/en/elasticsearch/reference/5.4/analysis-lowercase-tokenfilter.html "Lowercase Token Filter")** ，但是由于单次执行了所有步骤，所以效率更高。 ## **输出示例** | `POST _analyze` `{` `"tokenizer"``: ``"lowercase"``,` `"text"``: ``"The 2 QUICK Brown-Foxes jumped over the lazy dog's bone."` `}` | 上面的句子会生成如下的词元: | `[ the, quick, brown, foxes, jumped, over, the, lazy, dog, s, bone ]` | ## **配置** **`lowercase`**** tokenizer**(小写分词器) 不支持配置。