The letter tokenizer breaks text into terms whenever it encounters a character which is not a letter. It does a reasonable job for most European languages, but does a terrible job for some Asian languages, where words are not separated by spaces.

Example output

POST _analyze
{
  "tokenizer": "letter",
  "text": "The 2 QUICK Brown-Foxes jumped over the lazy dog's bone."
}

The above sentence would produce the following terms:

[ The, QUICK, Brown, Foxes, jumped, over, the, lazy, dog, s, bone ]

Configuration

The letter tokenizer is not configurable.